

<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://integralife.com/role/BasisOfPresentation" xlink:href="iart-20180630.xsd#BasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BasisOfPresentationNarrativeDetails" xlink:href="iart-20180630.xsd#BasisOfPresentationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BasisOfPresentationPolicies" xlink:href="iart-20180630.xsd#BasisOfPresentationPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestiture" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestiture" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestitureNarrativeDetails" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestitureNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestitureProFormaInformationDetails" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestitureProFormaInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestitureScheduleOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestitureScheduleOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestitureScheduleOfAssetsAndLiabilitiesDivestedDetails" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestitureScheduleOfAssetsAndLiabilitiesDivestedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/BusinessAcquisitionsAndDivestitureTables" xlink:href="iart-20180630.xsd#BusinessAcquisitionsAndDivestitureTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CommitmentsAndContingencies" xlink:href="iart-20180630.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CommitmentsAndContingenciesFairValueContingentConsiderationDetails" xlink:href="iart-20180630.xsd#CommitmentsAndContingenciesFairValueContingentConsiderationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CommitmentsAndContingenciesNarrativeDetails" xlink:href="iart-20180630.xsd#CommitmentsAndContingenciesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CommitmentsAndContingenciesTables" xlink:href="iart-20180630.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CommittmentsAndContingenciesFairValueSupplyAgreementDetails" xlink:href="iart-20180630.xsd#CommittmentsAndContingenciesFairValueSupplyAgreementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/ComprehensiveIncome" xlink:href="iart-20180630.xsd#ComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/ComprehensiveIncomeNarrativeDetails" xlink:href="iart-20180630.xsd#ComprehensiveIncomeNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/ComprehensiveIncomeScheduleOfChangesInAccumulatedOtherComprehensiveIncomeByComponentDetails" xlink:href="iart-20180630.xsd#ComprehensiveIncomeScheduleOfChangesInAccumulatedOtherComprehensiveIncomeByComponentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/ComprehensiveIncomeScheduleOfComprehensiveIncomeDetails" xlink:href="iart-20180630.xsd#ComprehensiveIncomeScheduleOfComprehensiveIncomeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/ComprehensiveIncomeTables" xlink:href="iart-20180630.xsd#ComprehensiveIncomeTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CondensedConsolidatedBalanceSheets" xlink:href="iart-20180630.xsd#CondensedConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:href="iart-20180630.xsd#CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:href="iart-20180630.xsd#CondensedConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncome" xlink:href="iart-20180630.xsd#CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/Debt" xlink:href="iart-20180630.xsd#Debt" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DebtContractualMaturityTableDetails" xlink:href="iart-20180630.xsd#DebtContractualMaturityTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DebtMaximumTotalLeverageRatioTableDetails" xlink:href="iart-20180630.xsd#DebtMaximumTotalLeverageRatioTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DebtNarrativeDetails" xlink:href="iart-20180630.xsd#DebtNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DebtTables" xlink:href="iart-20180630.xsd#DebtTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DefinedBenefitPlans" xlink:href="iart-20180630.xsd#DefinedBenefitPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DefinedBenefitPlansNarrativeDetails" xlink:href="iart-20180630.xsd#DefinedBenefitPlansNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstruments" xlink:href="iart-20180630.xsd#DerivativeInstruments" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsEffectOfDerivativeInstrumentsDesignatedCashFlowHedgesOnStatementsOfOperationsDetails" xlink:href="iart-20180630.xsd#DerivativeInstrumentsEffectOfDerivativeInstrumentsDesignatedCashFlowHedgesOnStatementsOfOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsFairValueOfDerivativeInstrumentsByBalanceSheetLocationDetails" xlink:href="iart-20180630.xsd#DerivativeInstrumentsFairValueOfDerivativeInstrumentsByBalanceSheetLocationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsNarrativeDetails" xlink:href="iart-20180630.xsd#DerivativeInstrumentsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsScheduleOfCrossCurrencySwapDerivativesDetails" xlink:href="iart-20180630.xsd#DerivativeInstrumentsScheduleOfCrossCurrencySwapDerivativesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsScheduleOfDerivativesDetails" xlink:href="iart-20180630.xsd#DerivativeInstrumentsScheduleOfDerivativesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DerivativeInstrumentsTables" xlink:href="iart-20180630.xsd#DerivativeInstrumentsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/DocumentAndEntityInformation" xlink:href="iart-20180630.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="iart-20180630.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsComponentsOfCompanysIdentifiableIntangibleAssetsDetails" xlink:href="iart-20180630.xsd#GoodwillAndOtherIntangibleAssetsComponentsOfCompanysIdentifiableIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:href="iart-20180630.xsd#GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfChangesInCarryingAmountOfGoodwillDetails" xlink:href="iart-20180630.xsd#GoodwillAndOtherIntangibleAssetsScheduleOfChangesInCarryingAmountOfGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:href="iart-20180630.xsd#GoodwillAndOtherIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/IncomeTaxes" xlink:href="iart-20180630.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/IncomeTaxesNarrativeDetails" xlink:href="iart-20180630.xsd#IncomeTaxesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/IncomeTaxesSummaryOfEffectiveTaxRateDetails" xlink:href="iart-20180630.xsd#IncomeTaxesSummaryOfEffectiveTaxRateDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/IncomeTaxesTables" xlink:href="iart-20180630.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/Inventories" xlink:href="iart-20180630.xsd#Inventories" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/InventoriesScheduleOfNetInventoriesDetails" xlink:href="iart-20180630.xsd#InventoriesScheduleOfNetInventoriesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/InventoriesTables" xlink:href="iart-20180630.xsd#InventoriesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/NetIncomePerShare" xlink:href="iart-20180630.xsd#NetIncomePerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/NetIncomePerShareBasicAndDilutedNetIncomePerShareDetails" xlink:href="iart-20180630.xsd#NetIncomePerShareBasicAndDilutedNetIncomePerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/NetIncomePerShareNarrativeDetails" xlink:href="iart-20180630.xsd#NetIncomePerShareNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/NetIncomePerShareTables" xlink:href="iart-20180630.xsd#NetIncomePerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomers" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomers" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersImpactOfAdoptionOnStatementOfOperationsDetails" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersImpactOfAdoptionOnStatementOfOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersNarrativeDetails" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersNarrativeRevenueRemainingPerformanceObligationDetails" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersNarrativeRevenueRemainingPerformanceObligationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersScheduleOfChangesInContractAssetsAndLiabilitiesDetails" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersScheduleOfChangesInContractAssetsAndLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersScheduleOfRevenuesDisaggregatedByMajorSourceDetails" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersScheduleOfRevenuesDisaggregatedByMajorSourceDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/RevenuesFromContractsWithCustomersTables" xlink:href="iart-20180630.xsd#RevenuesFromContractsWithCustomersTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/SegmentAndGeographicInformation" xlink:href="iart-20180630.xsd#SegmentAndGeographicInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/SegmentAndGeographicInformationNarrativeDetails" xlink:href="iart-20180630.xsd#SegmentAndGeographicInformationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/SegmentAndGeographicInformationNetSalesAndProfitByReportableSegmentDetails" xlink:href="iart-20180630.xsd#SegmentAndGeographicInformationNetSalesAndProfitByReportableSegmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/SegmentAndGeographicInformationTables" xlink:href="iart-20180630.xsd#SegmentAndGeographicInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/SegmentAndGeographicInformationTotalRevenueByMajorGeographicAreaDetails" xlink:href="iart-20180630.xsd#SegmentAndGeographicInformationTotalRevenueByMajorGeographicAreaDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/StockBasedCompensation" xlink:href="iart-20180630.xsd#StockBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/StockBasedCompensationNarrativeDetails" xlink:href="iart-20180630.xsd#StockBasedCompensationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/TreasuryStock" xlink:href="iart-20180630.xsd#TreasuryStock" xlink:type="simple" />
  <link:roleRef roleURI="http://integralife.com/role/TreasuryStockNarrativeDetails" xlink:href="iart-20180630.xsd#TreasuryStockNarrativeDetails" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:definitionLink xlink:role="http://integralife.com/role/BasisOfPresentation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/BasisOfPresentationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_6794C165B4922F2EFB4CD158E1BEB360" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionTable" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_4DA0FC812BD5D3F8EBAED158E1BEB477" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_6794C165B4922F2EFB4CD158E1BEB360" xlink:to="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_4DA0FC812BD5D3F8EBAED158E1BEB477" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_EA5DD825137A83B70600D158E1BEDA40" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_4DA0FC812BD5D3F8EBAED158E1BEB477" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_EA5DD825137A83B70600D158E1BEDA40" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_D64203FE7E9FD2544124D158E1BE6DAD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_EA5DD825137A83B70600D158E1BEDA40" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_D64203FE7E9FD2544124D158E1BE6DAD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_D64203FE7E9FD2544124D158E1BE6DAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_EA5DD825137A83B70600D158E1BEDA40" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_D64203FE7E9FD2544124D158E1BE6DAD" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_PublicOfferingMember" xlink:label="loc_iart_PublicOfferingMember_776FB3AEE73A57A75C94D158E1BE2D87" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_D64203FE7E9FD2544124D158E1BE6DAD" xlink:to="loc_iart_PublicOfferingMember_776FB3AEE73A57A75C94D158E1BE2D87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_D56DF64F34EEBE1CFEB9D158E1BED11D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_4DA0FC812BD5D3F8EBAED158E1BEB477" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_D56DF64F34EEBE1CFEB9D158E1BED11D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_89F92570933FDAAEECF8D158E1BEDECF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_D56DF64F34EEBE1CFEB9D158E1BED11D" xlink:to="loc_us-gaap_TypeOfAdoptionMember_89F92570933FDAAEECF8D158E1BEDECF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_89F92570933FDAAEECF8D158E1BEDECF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_D56DF64F34EEBE1CFEB9D158E1BED11D" xlink:to="loc_us-gaap_TypeOfAdoptionMember_89F92570933FDAAEECF8D158E1BEDECF" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AccountingStandardsUpdate201802Member" xlink:label="loc_iart_AccountingStandardsUpdate201802Member_28BD9F53A6A222E5968ED158E1BEE12A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_89F92570933FDAAEECF8D158E1BEDECF" xlink:to="loc_iart_AccountingStandardsUpdate201802Member_28BD9F53A6A222E5968ED158E1BEE12A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionAxis" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionAxis_4456117F8C8CD6ADE8C4D158E1BE4893" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_4DA0FC812BD5D3F8EBAED158E1BEB477" xlink:to="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionAxis_4456117F8C8CD6ADE8C4D158E1BE4893" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPrinciplesEarlyAdoptionMember" xlink:label="loc_us-gaap_NewAccountingPrinciplesEarlyAdoptionMember_91DFF395A9929F2AA080D158E1BE8F4F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionAxis_4456117F8C8CD6ADE8C4D158E1BE4893" xlink:to="loc_us-gaap_NewAccountingPrinciplesEarlyAdoptionMember_91DFF395A9929F2AA080D158E1BE8F4F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPrinciplesEarlyAdoptionMember" xlink:label="loc_us-gaap_NewAccountingPrinciplesEarlyAdoptionMember_91DFF395A9929F2AA080D158E1BE8F4F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionAxis_4456117F8C8CD6ADE8C4D158E1BE4893" xlink:to="loc_us-gaap_NewAccountingPrinciplesEarlyAdoptionMember_91DFF395A9929F2AA080D158E1BE8F4F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionEffectMember" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionEffectMember_5CD66703C66C34281621D158E1BEBBD2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPrinciplesEarlyAdoptionMember_91DFF395A9929F2AA080D158E1BE8F4F" xlink:to="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionEffectMember_5CD66703C66C34281621D158E1BEBBD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1E839FB83B895CF43B86D173E97DBD63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_6794C165B4922F2EFB4CD158E1BEB360" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1E839FB83B895CF43B86D173E97DBD63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_545BB418ADC2CF2D8345D158E1BEBADA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_6794C165B4922F2EFB4CD158E1BEB360" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_545BB418ADC2CF2D8345D158E1BEBADA" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings" xlink:label="loc_iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings_6248AEC69EBE1FE7C5E9D158E1BE0E46" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_6794C165B4922F2EFB4CD158E1BEB360" xlink:to="loc_iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings_6248AEC69EBE1FE7C5E9D158E1BE0E46" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/BasisOfPresentationPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestiture" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestitureNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_52E3DB5FD1569354AB96D37525B56C3D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_52E3DB5FD1569354AB96D37525B56C3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_CF662DEBB68570AB06D2D37525B5D56C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_52E3DB5FD1569354AB96D37525B56C3D" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_CF662DEBB68570AB06D2D37525B5D56C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_CF662DEBB68570AB06D2D37525B5D56C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_52E3DB5FD1569354AB96D37525B56C3D" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_CF662DEBB68570AB06D2D37525B5D56C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_2A2A2D663F7DC18C4300D37525B6C734" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_CF662DEBB68570AB06D2D37525B5D56C" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_2A2A2D663F7DC18C4300D37525B6C734" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_5C419EF5A488041253A6D37525B66556" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5C419EF5A488041253A6D37525B66556" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5C419EF5A488041253A6D37525B66556" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5C419EF5A488041253A6D37525B66556" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanMember" xlink:label="loc_iart_CodmanMember_B85B1F0DB8BC6B13AD1BD37525B6E220" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C" xlink:to="loc_iart_CodmanMember_B85B1F0DB8BC6B13AD1BD37525B6E220" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DermaSciencesMember" xlink:label="loc_iart_DermaSciencesMember_7D027281042C8ED7B552D37525B771A0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_301F155EA0D0C74F6FC2D37525B6348C" xlink:to="loc_iart_DermaSciencesMember_7D027281042C8ED7B552D37525B771A0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_B3EE1CAB491BECBE9718D37525B7A07F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_CreditFacilityAxis_B3EE1CAB491BECBE9718D37525B7A07F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_2B3C3B31DB277D78A72ED37525B70AED_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_B3EE1CAB491BECBE9718D37525B7A07F" xlink:to="loc_us-gaap_CreditFacilityDomain_2B3C3B31DB277D78A72ED37525B70AED_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_2B3C3B31DB277D78A72ED37525B70AED" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_B3EE1CAB491BECBE9718D37525B7A07F" xlink:to="loc_us-gaap_CreditFacilityDomain_2B3C3B31DB277D78A72ED37525B70AED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_AF2F4385D5C801982B11D37525B787C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_2B3C3B31DB277D78A72ED37525B70AED" xlink:to="loc_us-gaap_SecuredDebtMember_AF2F4385D5C801982B11D37525B787C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_14E43F120BC16A068907D37525B87B98" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_DebtInstrumentAxis_14E43F120BC16A068907D37525B87B98" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_C4830DC75EA94D52C591D37525B885AA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_14E43F120BC16A068907D37525B87B98" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_C4830DC75EA94D52C591D37525B885AA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_C4830DC75EA94D52C591D37525B885AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_14E43F120BC16A068907D37525B87B98" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_C4830DC75EA94D52C591D37525B885AA" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TermLoanFacilityMember" xlink:label="loc_iart_TermLoanFacilityMember_9C15DB043EA35BA3B96FD37525B856F8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_C4830DC75EA94D52C591D37525B885AA" xlink:to="loc_iart_TermLoanFacilityMember_9C15DB043EA35BA3B96FD37525B856F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_2C02CB29A16CBE35A9CED37525B8FF08" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_2C02CB29A16CBE35A9CED37525B8FF08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_113C32A617EF455594DBD37525B93888_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_2C02CB29A16CBE35A9CED37525B8FF08" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_113C32A617EF455594DBD37525B93888_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_113C32A617EF455594DBD37525B93888" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_2C02CB29A16CBE35A9CED37525B8FF08" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_113C32A617EF455594DBD37525B93888" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_8D078D222DE2266C7803D37525B9A87E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_113C32A617EF455594DBD37525B93888" xlink:to="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_8D078D222DE2266C7803D37525B9A87E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_24CE4DFD60DE825662B7D37525B905B4" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_24CE4DFD60DE825662B7D37525B905B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_77FFD354DD2C64F125F8D37525B9823E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_24CE4DFD60DE825662B7D37525B905B4" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_77FFD354DD2C64F125F8D37525B9823E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_77FFD354DD2C64F125F8D37525B9823E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_24CE4DFD60DE825662B7D37525B905B4" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_77FFD354DD2C64F125F8D37525B9823E" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_313FC874D2335CCA5129D37525BA55D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_77FFD354DD2C64F125F8D37525B9823E" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_313FC874D2335CCA5129D37525BA55D9" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_C58A9A9ED43DF67193A4D37525BAACCB" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_dei_LegalEntityAxis_C58A9A9ED43DF67193A4D37525BAACCB" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_CB26A85A8F73553929E3D37525BABF2A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_C58A9A9ED43DF67193A4D37525BAACCB" xlink:to="loc_dei_EntityDomain_CB26A85A8F73553929E3D37525BABF2A_default" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_CB26A85A8F73553929E3D37525BABF2A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_C58A9A9ED43DF67193A4D37525BAACCB" xlink:to="loc_dei_EntityDomain_CB26A85A8F73553929E3D37525BABF2A" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DermaSciencesMember" xlink:label="loc_iart_DermaSciencesMember_F0CA2DF0316C811C9AE8D37525BB3AB6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_CB26A85A8F73553929E3D37525BABF2A" xlink:to="loc_iart_DermaSciencesMember_F0CA2DF0316C811C9AE8D37525BB3AB6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_753D831577D7390DA614D37525BB2733" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_753D831577D7390DA614D37525BB2733" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_65E406F588E11979C54DD37525BB84D3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_753D831577D7390DA614D37525BB2733" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_65E406F588E11979C54DD37525BB84D3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_65E406F588E11979C54DD37525BB84D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_753D831577D7390DA614D37525BB2733" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_65E406F588E11979C54DD37525BB84D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProductConcentrationRiskMember" xlink:label="loc_us-gaap_ProductConcentrationRiskMember_8BC6DC426618B025F62CD37525BC65B7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_65E406F588E11979C54DD37525BB84D3" xlink:to="loc_us-gaap_ProductConcentrationRiskMember_8BC6DC426618B025F62CD37525BC65B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_66AB7B93321CE3CCC8C7D37525BC405E" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_srt_ProductOrServiceAxis_66AB7B93321CE3CCC8C7D37525BC405E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_6BB6DFFEC04AAD60EA23D37525BCA57C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_66AB7B93321CE3CCC8C7D37525BC405E" xlink:to="loc_srt_ProductsAndServicesDomain_6BB6DFFEC04AAD60EA23D37525BCA57C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_6BB6DFFEC04AAD60EA23D37525BCA57C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_66AB7B93321CE3CCC8C7D37525BC405E" xlink:to="loc_srt_ProductsAndServicesDomain_6BB6DFFEC04AAD60EA23D37525BCA57C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BioDMorselizedAmnioticMembraneBasedProductsMember" xlink:label="loc_iart_BioDMorselizedAmnioticMembraneBasedProductsMember_D670FE4D9A3EDA03525CD37525BC7B42" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6BB6DFFEC04AAD60EA23D37525BCA57C" xlink:to="loc_iart_BioDMorselizedAmnioticMembraneBasedProductsMember_D670FE4D9A3EDA03525CD37525BC7B42" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationByTypeAxis" xlink:label="loc_us-gaap_ContingentConsiderationByTypeAxis_E7B970DE61D300C8118DD37525C29936" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_ContingentConsiderationByTypeAxis_E7B970DE61D300C8118DD37525C29936" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_E7B970DE61D300C8118DD37525C29936" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_E7B970DE61D300C8118DD37525C29936" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BioDEarnoutPaymentsMember" xlink:label="loc_iart_BioDEarnoutPaymentsMember_ED82F6B9FB7AA967B819D37525C30B43" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF" xlink:to="loc_iart_BioDEarnoutPaymentsMember_ED82F6B9FB7AA967B819D37525C30B43" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ProductPaymentContingentConsiderationMember" xlink:label="loc_iart_ProductPaymentContingentConsiderationMember_009BB94AD01D337D3329D37525C35591" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF" xlink:to="loc_iart_ProductPaymentContingentConsiderationMember_009BB94AD01D337D3329D37525C35591" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_MedihoneyEarnoutPaymentsMember" xlink:label="loc_iart_MedihoneyEarnoutPaymentsMember_D9170015C9F4B6F9DE7AD37525C33535" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_0A59CB78974CB071358AD37525C284DF" xlink:to="loc_iart_MedihoneyEarnoutPaymentsMember_D9170015C9F4B6F9DE7AD37525C33535" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="loc_us-gaap_NonrecurringAdjustmentAxis_A089240CD7B5525A4C7DD37525C3172C" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_927027216EED3E6D8BA5D37525B41274" xlink:to="loc_us-gaap_NonrecurringAdjustmentAxis_A089240CD7B5525A4C7DD37525C3172C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_A089240CD7B5525A4C7DD37525C3172C" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_A089240CD7B5525A4C7DD37525C3172C" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueAdjustmentToInventoryMember" xlink:label="loc_us-gaap_FairValueAdjustmentToInventoryMember_DB527E63FEBA17020BB2D37525C4BA95" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778" xlink:to="loc_us-gaap_FairValueAdjustmentToInventoryMember_DB527E63FEBA17020BB2D37525C4BA95" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestExpenseIntangibleAssetAmortizationandExternalExpensesRelatedtoAcquisitionMember" xlink:label="loc_iart_InterestExpenseIntangibleAssetAmortizationandExternalExpensesRelatedtoAcquisitionMember_0A726576D5F991C661EED37525C48633" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_F323D2B506669FC2AC08D37525C45778" xlink:to="loc_iart_InterestExpenseIntangibleAssetAmortizationandExternalExpensesRelatedtoAcquisitionMember_0A726576D5F991C661EED37525C48633" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_6E4D929BE881DE2B5D55D37525C52A89" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_6E4D929BE881DE2B5D55D37525C52A89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_A54BAC4E964D3FC04B0BD37525C5B429" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_A54BAC4E964D3FC04B0BD37525C5B429" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_420BC00FDEC45C248CF9D37525C555E9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_420BC00FDEC45C248CF9D37525C555E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_EDD6E068B7AA151B3619D37525C50EFD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_EDD6E068B7AA151B3619D37525C50EFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_3DA5EA03A18E062A0914D37525C5347F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_3DA5EA03A18E062A0914D37525C5347F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_4B457381F7371F993637D37525C61AA2" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_4B457381F7371F993637D37525C61AA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromPreviousAcquisition" xlink:label="loc_us-gaap_ProceedsFromPreviousAcquisition_78A2432F62A811B6938AD37525C62A7E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_ProceedsFromPreviousAcquisition_78A2432F62A811B6938AD37525C62A7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_6915A559A5EC6FC669CBD37525C6B56B" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_6915A559A5EC6FC669CBD37525C6B56B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_225FEFCFE1AE435881EED37525C6F362" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_225FEFCFE1AE435881EED37525C6F362" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_6330EFDC1AB7427779B4D37525C6B7E9" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_6330EFDC1AB7427779B4D37525C6B7E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_44E3757D94DC9BA0A60BD37525C7DF5B" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_44E3757D94DC9BA0A60BD37525C7DF5B" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DisposalGroupIncludingDiscontinuedOperationAssetsProvidedUponTerminationOfTransitionalSupplyAgreementLiabilities" xlink:label="loc_iart_DisposalGroupIncludingDiscontinuedOperationAssetsProvidedUponTerminationOfTransitionalSupplyAgreementLiabilities_0BA53DD0E87CA615A293D37525C7E137" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_DisposalGroupIncludingDiscontinuedOperationAssetsProvidedUponTerminationOfTransitionalSupplyAgreementLiabilities_0BA53DD0E87CA615A293D37525C7E137" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_83A6BBC4E3B58FEDB8ADD37525C704F6" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_83A6BBC4E3B58FEDB8ADD37525C704F6" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationConsiderationTransferredOtherClosingExpenses" xlink:label="loc_iart_BusinessCombinationConsiderationTransferredOtherClosingExpenses_2D4426F653D49CF6840ED37525C7B7A3" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_BusinessCombinationConsiderationTransferredOtherClosingExpenses_2D4426F653D49CF6840ED37525C7B7A3" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationConsiderationTransferredOtherStockPlanSettlement" xlink:label="loc_iart_BusinessCombinationConsiderationTransferredOtherStockPlanSettlement_4DDC50B35EE09D14D4ABD37525C71E30" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_BusinessCombinationConsiderationTransferredOtherStockPlanSettlement_4DDC50B35EE09D14D4ABD37525C71E30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_519946613FB8195A284DD37525C8C537" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_519946613FB8195A284DD37525C8C537" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet_4A80F61DC8D6F2DAC62CD37525C8BC24" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet_4A80F61DC8D6F2DAC62CD37525C8BC24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_B711493F4E0403678937D37525C8F774" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_B711493F4E0403678937D37525C8F774" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic_3D8EB40AE1A8910E29C8D37525C82390" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic_3D8EB40AE1A8910E29C8D37525C82390" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:label="loc_us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_63049659F6E3FD6CEE6BD37525C8D54C" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_63049659F6E3FD6CEE6BD37525C8D54C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_861AA44E348D4CD1673ED37525C81FD6" xlink:type="locator" />
    <link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_861AA44E348D4CD1673ED37525C81FD6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="loc_us-gaap_DeferredTaxAssetsOther_645CF47F65A5EE6FD03DD37525C920A5" xlink:type="locator" />
    <link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DeferredTaxAssetsOther_645CF47F65A5EE6FD03DD37525C920A5" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxLiabilities" xlink:label="loc_iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxLiabilities_635AE9998912A4BFD243D37525C95D7C" xlink:type="locator" />
    <link:definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxLiabilities_635AE9998912A4BFD243D37525C95D7C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets" xlink:label="loc_iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets_BB6C96C5F4761442FA3BD37525C91625" xlink:type="locator" />
    <link:definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets_BB6C96C5F4761442FA3BD37525C91625" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_8780BAAB509DFD82BE58D37525C9441C" xlink:type="locator" />
    <link:definitionArc order="25" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_8780BAAB509DFD82BE58D37525C9441C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FairValueInputsRevenueVolatility" xlink:label="loc_iart_FairValueInputsRevenueVolatility_077C4B699DABAFC920F7D37525C9B521" xlink:type="locator" />
    <link:definitionArc order="26" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_FairValueInputsRevenueVolatility_077C4B699DABAFC920F7D37525C9B521" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentMeasurementInput" xlink:label="loc_us-gaap_DebtInstrumentMeasurementInput_7A062104E6973FB61EF8D37525CA1F2D" xlink:type="locator" />
    <link:definitionArc order="27" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_DebtInstrumentMeasurementInput_7A062104E6973FB61EF8D37525CA1F2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_B4388AB00ED356A440BBD37525CAE3BA" xlink:type="locator" />
    <link:definitionArc order="28" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_B4388AB00ED356A440BBD37525CAE3BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_CD2425B873B122B75218D37525CA1CFC" xlink:type="locator" />
    <link:definitionArc order="29" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_CD2425B873B122B75218D37525CA1CFC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FairValueInputsProductPaymentRate" xlink:label="loc_iart_FairValueInputsProductPaymentRate_E7A6E10AE26188F068F7D37525CA4A39" xlink:type="locator" />
    <link:definitionArc order="30" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_iart_FairValueInputsProductPaymentRate_E7A6E10AE26188F068F7D37525CA4A39" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_01019817B157E12ABAD9D37525CAC304" xlink:type="locator" />
    <link:definitionArc order="31" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_01019817B157E12ABAD9D37525CAC304" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_BFCB06877BAABF62DD8CD37525CAA277" xlink:type="locator" />
    <link:definitionArc order="32" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_BFCB06877BAABF62DD8CD37525CAA277" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_726DBA5BF515CF8E25DCD37525CBDB6A" xlink:type="locator" />
    <link:definitionArc order="33" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7873757359CAC5295DD37525C5B788" xlink:to="loc_us-gaap_NetIncomeLoss_726DBA5BF515CF8E25DCD37525CBDB6A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestitureProFormaInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestitureScheduleOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1637796135CE5BA4C081CEC3100B6EB5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1637796135CE5BA4C081CEC3100B6EB5" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9DDE281CF72794C577D1CEC3100BB6DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1637796135CE5BA4C081CEC3100B6EB5" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9DDE281CF72794C577D1CEC3100BB6DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9DDE281CF72794C577D1CEC3100BB6DA" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9DDE281CF72794C577D1CEC3100BB6DA" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanMember" xlink:label="loc_iart_CodmanMember_4148884D84CF773DE095CEC3100B9867" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB" xlink:to="loc_iart_CodmanMember_4148884D84CF773DE095CEC3100B9867" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DermaSciencesMember" xlink:label="loc_iart_DermaSciencesMember_7A3D7C4CAD680ABEBA87CEC3100BFDEA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FCAA69B5EBCE1CA50904CEC3100BFAEB" xlink:to="loc_iart_DermaSciencesMember_7A3D7C4CAD680ABEBA87CEC3100BFDEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_82E6BD39404959391AC4CEC3100B2189" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1637796135CE5BA4C081CEC3100B6EB5" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_82E6BD39404959391AC4CEC3100B2189" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5676D343BCFE4151EBD3CEC3100B9FA2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_82E6BD39404959391AC4CEC3100B2189" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5676D343BCFE4151EBD3CEC3100B9FA2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5676D343BCFE4151EBD3CEC3100B9FA2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_82E6BD39404959391AC4CEC3100B2189" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5676D343BCFE4151EBD3CEC3100B9FA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_122F2C41C6AB15BAB227CEC3100BE9DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5676D343BCFE4151EBD3CEC3100B9FA2" xlink:to="loc_us-gaap_TradeNamesMember_122F2C41C6AB15BAB227CEC3100BE9DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_AE3D40DD4435C6C55EB2CEC3100BCA53" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1637796135CE5BA4C081CEC3100B6EB5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_AE3D40DD4435C6C55EB2CEC3100BCA53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_AE3D40DD4435C6C55EB2CEC3100BCA53" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_AE3D40DD4435C6C55EB2CEC3100BCA53" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_97C81005AA60EBB48BE6CEC3100BD032" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:to="loc_us-gaap_CustomerRelationshipsMember_97C81005AA60EBB48BE6CEC3100BD032" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_0C55BA0E9D67036D1037CEC3100B7B41" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_0C55BA0E9D67036D1037CEC3100B7B41" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_CEE25EACAFCED5FA6915CEC3100B3FC3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_CEE25EACAFCED5FA6915CEC3100B3FC3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NoncompeteAgreementsMember" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_F791A18337CD3B3353DCCEC3101BE099" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A7E8345DB3EF0491031FCEC3100BE6AD" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_F791A18337CD3B3353DCCEC3101BE099" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_A7B65F1CD67B732F0C1ECEC3101B4955" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_A7B65F1CD67B732F0C1ECEC3101B4955" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedShorttermInvestments" xlink:label="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedShorttermInvestments_8B6180BBBAEB6419002BCEC3101BF1AC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedShorttermInvestments_8B6180BBBAEB6419002BCEC3101BF1AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_42D7822AE1A29BD29DE2CEC3101B12A1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_42D7822AE1A29BD29DE2CEC3101B12A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_12047F91BD81A23FB913CEC3101BDEE2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_12047F91BD81A23FB913CEC3101BDEE2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_B4D5ABC7722D720C5F12CEC3101B3122" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_B4D5ABC7722D720C5F12CEC3101B3122" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsHeldForSale" xlink:label="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsHeldForSale_7EF00E6B6F347D69F9B1CEC3101B940F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsHeldForSale_7EF00E6B6F347D69F9B1CEC3101B940F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_B7F194A59336BA2631C9CEC3101BFEDA" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_B7F194A59336BA2631C9CEC3101BFEDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_4F085C4545A60E814BF7CEC3101B89AF" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_4F085C4545A60E814BF7CEC3101B89AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillAbstract_39613F56CC219A6AE219CEC3101BE7AC" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillAbstract_39613F56CC219A6AE219CEC3101BE7AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_5B7DF4508456CE3B7035CEC3101BED36" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillAbstract_39613F56CC219A6AE219CEC3101BE7AC" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_5B7DF4508456CE3B7035CEC3101BED36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_00D3E55A0EECFB593FD4CEC3101B73C3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillAbstract_39613F56CC219A6AE219CEC3101BE7AC" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_00D3E55A0EECFB593FD4CEC3101B73C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_36F79C1DBD671681E4E9CEC3101BF9EB" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_Goodwill_36F79C1DBD671681E4E9CEC3101BF9EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_230005916B62B4813C38CEC3101B62A7" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_230005916B62B4813C38CEC3101B62A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_4981211D70ADF3CD9A3ECEC3101B6BD5" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_4981211D70ADF3CD9A3ECEC3101B6BD5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_CD086BFD9E974A989147CEC3101BE9FC" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_CD086BFD9E974A989147CEC3101BE9FC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" xlink:label="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_407861224B21F875B9F7CEC3101B69BC" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_407861224B21F875B9F7CEC3101B69BC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedPension" xlink:label="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedPension_0D2B53D884755873E96ECEC3101B7A3A" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_iart_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedPension_0D2B53D884755873E96ECEC3101B7A3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_30C0CBBCE62FBA0A07DBCEC3101B4C60" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_30C0CBBCE62FBA0A07DBCEC3101B4C60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_182A6CDD0A4926744D01CEC3101B22EE" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_182A6CDD0A4926744D01CEC3101B22EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability_5ECBBC1C25C15AD35A1FCEC3101B700E" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedContingentLiability_5ECBBC1C25C15AD35A1FCEC3101B700E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_89CEEDAF0C3FB9E0320BCEC3101B6A89" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_89CEEDAF0C3FB9E0320BCEC3101B6A89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_0A1F33F408E466C89972CEC3101B8105" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_0A1F33F408E466C89972CEC3101B8105" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_647D3F93B66207758B3ECEC3101B6732" xlink:type="locator" />
    <link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_FC914C8901A4B0E1B4B3CEC3101B1D77" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_647D3F93B66207758B3ECEC3101B6732" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestitureScheduleOfAssetsAndLiabilitiesDivestedDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B532500B644312BF4B5EA559799DADA0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B532500B644312BF4B5EA559799DADA0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_56213C27D1881425B3F0A559799D2CE7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B532500B644312BF4B5EA559799DADA0" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_56213C27D1881425B3F0A559799D2CE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_49F6DB20169FE73C8FA0A559799DA82E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_56213C27D1881425B3F0A559799D2CE7" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_49F6DB20169FE73C8FA0A559799DA82E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_49F6DB20169FE73C8FA0A559799DA82E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_56213C27D1881425B3F0A559799D2CE7" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_49F6DB20169FE73C8FA0A559799DA82E" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_1B9ACBF6BD1C531A5E97A559799DA7E1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_49F6DB20169FE73C8FA0A559799DA82E" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_1B9ACBF6BD1C531A5E97A559799DA7E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_D9D50FB77624143FA6BCA559799D4913" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_B532500B644312BF4B5EA559799DADA0" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_D9D50FB77624143FA6BCA559799D4913" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_072452DC7BBA88635E75A559799D11EB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_D9D50FB77624143FA6BCA559799D4913" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_072452DC7BBA88635E75A559799D11EB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_072452DC7BBA88635E75A559799D11EB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_D9D50FB77624143FA6BCA559799D4913" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_072452DC7BBA88635E75A559799D11EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_2695B89E47A986ED1184A559799DCDDB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_072452DC7BBA88635E75A559799D11EB" xlink:to="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_2695B89E47A986ED1184A559799DCDDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationInventoryCurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationInventoryCurrent_743C9616423CBB5C21A4A559799D0CD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationInventoryCurrent_743C9616423CBB5C21A4A559799D0CD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent_D4B71121FF93FE1FD861A559799DF253" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent_D4B71121FF93FE1FD861A559799DF253" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DisposalGroupIncludingDiscontinuedOperationAssetsHeldForSale" xlink:label="loc_iart_DisposalGroupIncludingDiscontinuedOperationAssetsHeldForSale_F8BF6770500EBBDFF93DA559799D4AC8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_iart_DisposalGroupIncludingDiscontinuedOperationAssetsHeldForSale_F8BF6770500EBBDFF93DA559799D4AC8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent_8E318B33154FEDCEEB51A559799D7407" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent_8E318B33154FEDCEEB51A559799D7407" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1_649394936C023221A095A559799DAFFC" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1_649394936C023221A095A559799DAFFC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_6610399AF3701A8D1FDEA559799DEC63" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_6610399AF3701A8D1FDEA559799DEC63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredRevenueCurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredRevenueCurrent_B81B309464CB6525532FA559799DD2C4" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredRevenueCurrent_B81B309464CB6525532FA559799DD2C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent_31BE8DC76F814952048FA559799D571B" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent_31BE8DC76F814952048FA559799D571B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_3E0FD7E6532DBC3DEC70A559799D8053" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8E93E0BE42422740572CA559799D7510" xlink:to="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_3E0FD7E6532DBC3DEC70A559799D8053" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/BusinessAcquisitionsAndDivestitureTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CommitmentsAndContingenciesFairValueContingentConsiderationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C13106A476A075A9252BC8C2D226F449" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C13106A476A075A9252BC8C2D226F449" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_8E10BDC81199F61DD631C8C2D2223F16" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_8E10BDC81199F61DD631C8C2D2223F16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C94AE2A0667BE3BD0951C8C2D222E841_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_8E10BDC81199F61DD631C8C2D2223F16" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C94AE2A0667BE3BD0951C8C2D222E841_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C94AE2A0667BE3BD0951C8C2D222E841" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_8E10BDC81199F61DD631C8C2D2223F16" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C94AE2A0667BE3BD0951C8C2D222E841" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ContingentConsiderationLiabilityMember" xlink:label="loc_iart_ContingentConsiderationLiabilityMember_867F5AF2E0F83EE84985C8C2D222E6CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C94AE2A0667BE3BD0951C8C2D222E841" xlink:to="loc_iart_ContingentConsiderationLiabilityMember_867F5AF2E0F83EE84985C8C2D222E6CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B30FE54A2BE81A78B58DC8C2D22385EB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B30FE54A2BE81A78B58DC8C2D22385EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_C2D85CAF7FEB110786BEC8C2D22365DD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B30FE54A2BE81A78B58DC8C2D22385EB" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_C2D85CAF7FEB110786BEC8C2D22365DD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_C2D85CAF7FEB110786BEC8C2D22365DD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_B30FE54A2BE81A78B58DC8C2D22385EB" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_C2D85CAF7FEB110786BEC8C2D22365DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_9097DAD2C63D34BAB088C8C2D223EBAC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_C2D85CAF7FEB110786BEC8C2D22365DD" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_9097DAD2C63D34BAB088C8C2D223EBAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_0CC48073575B3EE2B66DC8C2D223E908" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_0CC48073575B3EE2B66DC8C2D223E908" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0CC48073575B3EE2B66DC8C2D223E908" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0CC48073575B3EE2B66DC8C2D223E908" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DermaSciencesMember" xlink:label="loc_iart_DermaSciencesMember_EF99CEB3C96D2F005092C8C2D224A6F0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8" xlink:to="loc_iart_DermaSciencesMember_EF99CEB3C96D2F005092C8C2D224A6F0" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ConfluentSurgicalInc.Member" xlink:label="loc_iart_ConfluentSurgicalInc.Member_346D7F86FD04ACA61FFDC8C2D2243D5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_BCC381C47596AE78CE72C8C2D2243DA8" xlink:to="loc_iart_ConfluentSurgicalInc.Member_346D7F86FD04ACA61FFDC8C2D2243D5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_F0B248344701B51B993EC8C2D2245597" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_F0B248344701B51B993EC8C2D2245597" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_F0B248344701B51B993EC8C2D2245597" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_F0B248344701B51B993EC8C2D2245597" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AccruedExpensesAndOtherCurrentLiabilitiesMember" xlink:label="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_855AB70A5E1CE6ACDCBCC8C2D22551FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC" xlink:to="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_855AB70A5E1CE6ACDCBCC8C2D22551FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_4F0A0F6F7A9F4C1053C2C8C2D2253C52" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_976B773DF2DAC8B9E133C8C2D224BACC" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_4F0A0F6F7A9F4C1053C2C8C2D2253C52" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_B3066190569EA8B19AFBC8C2D2251D34" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_3B6D355DD6276F73C1FDC8C2D2218E6F" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_B3066190569EA8B19AFBC8C2D2251D34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_47181C64A0B8DAB67043C8C2D225B8A2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_B3066190569EA8B19AFBC8C2D2251D34" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_47181C64A0B8DAB67043C8C2D225B8A2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_47181C64A0B8DAB67043C8C2D225B8A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_B3066190569EA8B19AFBC8C2D2251D34" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_47181C64A0B8DAB67043C8C2D225B8A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_6C3CDC2C11A47A933289C8C2D2261EB6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_47181C64A0B8DAB67043C8C2D225B8A2" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_6C3CDC2C11A47A933289C8C2D2261EB6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C13106A476A075A9252BC8C2D226F449" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_13C5D5BFD0B96B7CC27FC8C2D2261725" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_13C5D5BFD0B96B7CC27FC8C2D2261725" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_3DA6EF1B4058E582988AC8C2D22738EE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_3DA6EF1B4058E582988AC8C2D22738EE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent" xlink:label="loc_iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent_90114808CD2590D2026BC8C2D227D29E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:to="loc_iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent_90114808CD2590D2026BC8C2D227D29E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_AB1F922B5EC691AF8370C8C2D227E24F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_AB1F922B5EC691AF8370C8C2D227E24F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_4B2BF34475D893BF7740C8C2D227F9B6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_1780B6072354624BD9DDC8C2D226A667" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_4B2BF34475D893BF7740C8C2D227F9B6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/CommitmentsAndContingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_A79E895D3CEDA02923CDA55977F5C767" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_A79E895D3CEDA02923CDA55977F5C767" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A79E895D3CEDA02923CDA55977F5C767" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A79E895D3CEDA02923CDA55977F5C767" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TEIMember" xlink:label="loc_iart_TEIMember_8085CA9A823DF9CD023DA55977F6B5DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE" xlink:to="loc_iart_TEIMember_8085CA9A823DF9CD023DA55977F6B5DE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ConfluentSurgicalInc.Member" xlink:label="loc_iart_ConfluentSurgicalInc.Member_67099D366A7743C4C1E1A55977F63A50" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE" xlink:to="loc_iart_ConfluentSurgicalInc.Member_67099D366A7743C4C1E1A55977F63A50" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DermaSciencesMember" xlink:label="loc_iart_DermaSciencesMember_B851E69BF8F08D68D396A55977F695F1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_930CF74C21FB4B75629FA55977F6DFCE" xlink:to="loc_iart_DermaSciencesMember_B851E69BF8F08D68D396A55977F695F1" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_8E929DEC826FA2265F36A55977F692F0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_dei_LegalEntityAxis_8E929DEC826FA2265F36A55977F692F0" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2C50BE5F47FFC4B0C8A5A55977F63D8E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_8E929DEC826FA2265F36A55977F692F0" xlink:to="loc_dei_EntityDomain_2C50BE5F47FFC4B0C8A5A55977F63D8E_default" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_2C50BE5F47FFC4B0C8A5A55977F63D8E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_8E929DEC826FA2265F36A55977F692F0" xlink:to="loc_dei_EntityDomain_2C50BE5F47FFC4B0C8A5A55977F63D8E" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ThirdPartyInsurerMember" xlink:label="loc_iart_ThirdPartyInsurerMember_2ED74BAD599D2472803DA55977F6A2A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_2C50BE5F47FFC4B0C8A5A55977F63D8E" xlink:to="loc_iart_ThirdPartyInsurerMember_2ED74BAD599D2472803DA55977F6A2A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_3C5F247DFB50007A6AB1A55977F6C7F9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_StatementScenarioAxis_3C5F247DFB50007A6AB1A55977F6C7F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_3C5F247DFB50007A6AB1A55977F6C7F9" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_3C5F247DFB50007A6AB1A55977F6C7F9" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_IndemnificationPeriodOneMember" xlink:label="loc_iart_IndemnificationPeriodOneMember_F51DC1C2FCC17EBBA6C7A55977F633B5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7" xlink:to="loc_iart_IndemnificationPeriodOneMember_F51DC1C2FCC17EBBA6C7A55977F633B5" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_IndemnificationPeriodTwoMember" xlink:label="loc_iart_IndemnificationPeriodTwoMember_C1AC79F682B07F1FA35FA55977F6DF30" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_0BAACE121F087F67EF53A55977F6C0C7" xlink:to="loc_iart_IndemnificationPeriodTwoMember_C1AC79F682B07F1FA35FA55977F6DF30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1CE473A39B14B8BBF875A55977F6DE60" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1CE473A39B14B8BBF875A55977F6DE60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_4083F73C5CEF4E04A5E1A55977F65DB8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1CE473A39B14B8BBF875A55977F6DE60" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_4083F73C5CEF4E04A5E1A55977F65DB8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_4083F73C5CEF4E04A5E1A55977F65DB8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1CE473A39B14B8BBF875A55977F6DE60" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_4083F73C5CEF4E04A5E1A55977F65DB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_B0D5D61F8A12AE269537A55977F65767" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_4083F73C5CEF4E04A5E1A55977F65DB8" xlink:to="loc_us-gaap_SubsequentEventMember_B0D5D61F8A12AE269537A55977F65767" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationByTypeAxis" xlink:label="loc_us-gaap_ContingentConsiderationByTypeAxis_AC7A15A2FF48A9B79A96A55977F6917E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_ContingentConsiderationByTypeAxis_AC7A15A2FF48A9B79A96A55977F6917E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_AC7A15A2FF48A9B79A96A55977F6917E" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_AC7A15A2FF48A9B79A96A55977F6917E" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CashConsiderationOneMember" xlink:label="loc_iart_CashConsiderationOneMember_812584F7C7331C29FA6DA55977F64AEE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61" xlink:to="loc_iart_CashConsiderationOneMember_812584F7C7331C29FA6DA55977F64AEE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CashConsiderationTwoMember" xlink:label="loc_iart_CashConsiderationTwoMember_E99D838C75E91A3BA896A55977F747D7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61" xlink:to="loc_iart_CashConsiderationTwoMember_E99D838C75E91A3BA896A55977F747D7" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BioDEarnoutPaymentsMember" xlink:label="loc_iart_BioDEarnoutPaymentsMember_1D4F9A507D52313F7C7DA55977F74F73" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_8689463409C9188CDF09A55977F68E61" xlink:to="loc_iart_BioDEarnoutPaymentsMember_1D4F9A507D52313F7C7DA55977F74F73" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_506056672FA0FD09C269A55977F716BF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_506056672FA0FD09C269A55977F716BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_8D7E588C24A6B5B13CE1A55977F73D8D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_506056672FA0FD09C269A55977F716BF" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_8D7E588C24A6B5B13CE1A55977F73D8D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_8D7E588C24A6B5B13CE1A55977F73D8D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_506056672FA0FD09C269A55977F716BF" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_8D7E588C24A6B5B13CE1A55977F73D8D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_0EF3643E5E4821C4D4A0A55977F79B56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_8D7E588C24A6B5B13CE1A55977F73D8D" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_0EF3643E5E4821C4D4A0A55977F79B56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_069794584AFCCFC67D64A55977F71E10" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_069794584AFCCFC67D64A55977F71E10" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_64DED05CE6A3E4236B04A55977F7D194_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_069794584AFCCFC67D64A55977F71E10" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_64DED05CE6A3E4236B04A55977F7D194_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_64DED05CE6A3E4236B04A55977F7D194" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_069794584AFCCFC67D64A55977F71E10" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_64DED05CE6A3E4236B04A55977F7D194" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ContingentConsiderationLiabilityMember" xlink:label="loc_iart_ContingentConsiderationLiabilityMember_F8AF98C716FE1429C0F8A55977F707A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_64DED05CE6A3E4236B04A55977F7D194" xlink:to="loc_iart_ContingentConsiderationLiabilityMember_F8AF98C716FE1429C0F8A55977F707A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentAxis" xlink:label="loc_us-gaap_SupplyCommitmentAxis_AC840230E3B56E5BE856A55977F70D89" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_81CAD6E5EF0C3D5733CDA55977F5D9A8" xlink:to="loc_us-gaap_SupplyCommitmentAxis_AC840230E3B56E5BE856A55977F70D89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentArrangementMember" xlink:label="loc_us-gaap_SupplyCommitmentArrangementMember_99484BA966040B348A47A55977F7D33C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SupplyCommitmentAxis_AC840230E3B56E5BE856A55977F70D89" xlink:to="loc_us-gaap_SupplyCommitmentArrangementMember_99484BA966040B348A47A55977F7D33C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentArrangementMember" xlink:label="loc_us-gaap_SupplyCommitmentArrangementMember_99484BA966040B348A47A55977F7D33C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SupplyCommitmentAxis_AC840230E3B56E5BE856A55977F70D89" xlink:to="loc_us-gaap_SupplyCommitmentArrangementMember_99484BA966040B348A47A55977F7D33C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SupplyCommitmentCurrentLongTermandAboveMarketMember" xlink:label="loc_iart_SupplyCommitmentCurrentLongTermandAboveMarketMember_88C83ABF52400C222A7BA55977F783EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplyCommitmentArrangementMember_99484BA966040B348A47A55977F7D33C" xlink:to="loc_iart_SupplyCommitmentCurrentLongTermandAboveMarketMember_88C83ABF52400C222A7BA55977F783EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_042A30D85D626D88CA13A55977F749A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_042A30D85D626D88CA13A55977F749A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_E81D788627EA42464317A55977F739F2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_E81D788627EA42464317A55977F739F2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueHigh_B54310C2658B85DF1259A55977F7BD48" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueHigh_B54310C2658B85DF1259A55977F7BD48" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_BusinessCombinationIndemnificationAssetsPeriodofIndemnification" xlink:label="loc_iart_BusinessCombinationIndemnificationAssetsPeriodofIndemnification_8F3F2DEB82BE98B8E940A55977F7021E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_iart_BusinessCombinationIndemnificationAssetsPeriodofIndemnification_8F3F2DEB82BE98B8E940A55977F7021E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueLow" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueLow_82251C1B76217E677A48A55977F794D7" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsRangeOfOutcomesValueLow_82251C1B76217E677A48A55977F794D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyReceivableProceeds" xlink:label="loc_us-gaap_LossContingencyReceivableProceeds_46AC7637016561E2BA7EA55977F765C9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_LossContingencyReceivableProceeds_46AC7637016561E2BA7EA55977F765C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyReceivable" xlink:label="loc_us-gaap_LossContingencyReceivable_2620681AAC0A23E6D6D0A55977F7DEFA" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_LossContingencyReceivable_2620681AAC0A23E6D6D0A55977F7DEFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_D749CF0ACF4B97ADE339A55977F805F8" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_D749CF0ACF4B97ADE339A55977F805F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow_49B70FC14A826A98A399A55977F8EAB4" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow_49B70FC14A826A98A399A55977F8EAB4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentMeasurementInput" xlink:label="loc_us-gaap_DebtInstrumentMeasurementInput_18BF899254EA5658A2EDA55977F81C87" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_DebtInstrumentMeasurementInput_18BF899254EA5658A2EDA55977F81C87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_B1DBF0B258D6BDD12AD1A55977F8828B" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_6FED28FFB01F51C2E90EA55977F7C629" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_B1DBF0B258D6BDD12AD1A55977F8828B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CommittmentsAndContingenciesFairValueSupplyAgreementDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C727BD2B1EDF294EC6ECA55977DC7C38" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C727BD2B1EDF294EC6ECA55977DC7C38" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_C4FA403C7E05E386CC1DA55977D8C131" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_C4FA403C7E05E386CC1DA55977D8C131" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C408619F9A1A9C96230AA55977D8EACD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_C4FA403C7E05E386CC1DA55977D8C131" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C408619F9A1A9C96230AA55977D8EACD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C408619F9A1A9C96230AA55977D8EACD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_C4FA403C7E05E386CC1DA55977D8C131" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C408619F9A1A9C96230AA55977D8EACD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommitmentsMember" xlink:label="loc_us-gaap_CommitmentsMember_6FE1E40284FBF56F2CFEA55977D92518" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_C408619F9A1A9C96230AA55977D8EACD" xlink:to="loc_us-gaap_CommitmentsMember_6FE1E40284FBF56F2CFEA55977D92518" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F5FFFF8B709610DFA705A55977D9A681" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F5FFFF8B709610DFA705A55977D9A681" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_E5C03CD147D4AB8E5670A55977D9A891_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F5FFFF8B709610DFA705A55977D9A681" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_E5C03CD147D4AB8E5670A55977D9A891_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_E5C03CD147D4AB8E5670A55977D9A891" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F5FFFF8B709610DFA705A55977D9A681" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_E5C03CD147D4AB8E5670A55977D9A891" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_FB34E7DDA613C10BB946A55977D905CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_E5C03CD147D4AB8E5670A55977D9A891" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_FB34E7DDA613C10BB946A55977D905CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_BE0EDC5AFFE2379006B4A55977D9802A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_BE0EDC5AFFE2379006B4A55977D9802A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_BE0EDC5AFFE2379006B4A55977D9802A" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_BE0EDC5AFFE2379006B4A55977D9802A" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AccruedExpensesAndOtherCurrentLiabilitiesMember" xlink:label="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_6D53A830D19A4CD17626A55977D9E7A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F" xlink:to="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_6D53A830D19A4CD17626A55977D9E7A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_3A2E7E09051591202D9DA55977D9C035" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_126A93F83ECAF244511DA55977D97A4F" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_3A2E7E09051591202D9DA55977D9C035" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentAxis" xlink:label="loc_us-gaap_SupplyCommitmentAxis_8155D94FAFCEE5491ABBA55977DA8153" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:to="loc_us-gaap_SupplyCommitmentAxis_8155D94FAFCEE5491ABBA55977DA8153" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentArrangementMember" xlink:label="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SupplyCommitmentAxis_8155D94FAFCEE5491ABBA55977DA8153" xlink:to="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentArrangementMember" xlink:label="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SupplyCommitmentAxis_8155D94FAFCEE5491ABBA55977DA8153" xlink:to="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplyCommitmentMember" xlink:label="loc_us-gaap_SupplyCommitmentMember_79C09EE9BD713E003455A55977DAC41C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878" xlink:to="loc_us-gaap_SupplyCommitmentMember_79C09EE9BD713E003455A55977DAC41C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SupplyCommitmentAboveMarketMember" xlink:label="loc_iart_SupplyCommitmentAboveMarketMember_E4B326E488EDA2B50DA0A55977DBBB8D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878" xlink:to="loc_iart_SupplyCommitmentAboveMarketMember_E4B326E488EDA2B50DA0A55977DBBB8D" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SupplyCommitmentAboveMarketLongTermMember" xlink:label="loc_iart_SupplyCommitmentAboveMarketLongTermMember_3B2F68E5DBFE14A4E8C2A55977DB0DE9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplyCommitmentArrangementMember_778E28F79643AE8CD023A55977DA8878" xlink:to="loc_iart_SupplyCommitmentAboveMarketLongTermMember_3B2F68E5DBFE14A4E8C2A55977DB0DE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_020389EE7338B88486DEA55977DC8F11" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_D2B7C68251A3CED3D6F4A55977D8E31B" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_020389EE7338B88486DEA55977DC8F11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_E8700997C96F41974909A55977DC79F7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_020389EE7338B88486DEA55977DC8F11" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_E8700997C96F41974909A55977DC79F7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_E8700997C96F41974909A55977DC79F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_020389EE7338B88486DEA55977DC8F11" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_E8700997C96F41974909A55977DC79F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_41A9BA2B37243F9A26C4A55977DC2684" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_E8700997C96F41974909A55977DC79F7" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_41A9BA2B37243F9A26C4A55977DC2684" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_C727BD2B1EDF294EC6ECA55977DC7C38" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_64C723441FF09A2908A8A55977DC66D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_64C723441FF09A2908A8A55977DC66D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_52EB43E46AAE8E5E55F7A55977DC7691" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_52EB43E46AAE8E5E55F7A55977DC7691" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent" xlink:label="loc_iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent_9DAF99D997A51F771EEBA55977DCDCAF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:to="loc_iart_FairValueMeasurementwithUnobservableInputsReconciliationLiabilityTransfersFromLongTermtoCurrent_9DAF99D997A51F771EEBA55977DCDCAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_421F1A6032CC645445BEA55977DC8818" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_421F1A6032CC645445BEA55977DC8818" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransferToAccountsPayable" xlink:label="loc_iart_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransferToAccountsPayable_469A397A53088A7A65A2A55977DCFD6F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_BB96747866B92AF440A9A55977DC7E9D" xlink:to="loc_iart_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransferToAccountsPayable_469A397A53088A7A65A2A55977DCFD6F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/ComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/ComprehensiveIncomeNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_310A3C0B0897580C5C77D158E04EB507" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_304E1010C67AF1F5D755D158E03F1B06" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_310A3C0B0897580C5C77D158E04EB507" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_304E1010C67AF1F5D755D158E03F1B06" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_7CF12B3ED0C73745C08BD158E03F9ED2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_304E1010C67AF1F5D755D158E03F1B06" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_7CF12B3ED0C73745C08BD158E03F9ED2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7CF12B3ED0C73745C08BD158E03F9ED2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7CF12B3ED0C73745C08BD158E03F9ED2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="loc_us-gaap_InterestExpenseMember_B43761A1A88FE973D50DD158E04E9DEA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C" xlink:to="loc_us-gaap_InterestExpenseMember_B43761A1A88FE973D50DD158E04E9DEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherExpenseMember" xlink:label="loc_us-gaap_OtherExpenseMember_C32D4523024E7F7C7A3AD158E04E60E5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6B073F6E81F4C9132764D158E03F900C" xlink:to="loc_us-gaap_OtherExpenseMember_C32D4523024E7F7C7A3AD158E04E60E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_31A50990A05825BA1109D158E04E1799" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_304E1010C67AF1F5D755D158E03F1B06" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_31A50990A05825BA1109D158E04E1799" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_93FB5CFFDB2982639765D158E04E2F03_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_31A50990A05825BA1109D158E04E1799" xlink:to="loc_us-gaap_EquityComponentDomain_93FB5CFFDB2982639765D158E04E2F03_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_93FB5CFFDB2982639765D158E04E2F03" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_31A50990A05825BA1109D158E04E1799" xlink:to="loc_us-gaap_EquityComponentDomain_93FB5CFFDB2982639765D158E04E2F03" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_2B354C377D3912E7A5F4D158E04E5072" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_93FB5CFFDB2982639765D158E04E2F03" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_2B354C377D3912E7A5F4D158E04E5072" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_5D9E6ACB89ACFC47F683D158E04E27AB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_310A3C0B0897580C5C77D158E04EB507" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_5D9E6ACB89ACFC47F683D158E04E27AB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/ComprehensiveIncomeScheduleOfChangesInAccumulatedOtherComprehensiveIncomeByComponentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_351E2687EB7360A7BD9BA5597826D379" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_B880BF77062458737695A55978269233" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_351E2687EB7360A7BD9BA5597826D379" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_B880BF77062458737695A55978269233" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_FBB50BA6BD0FAE352185A55978261DCB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_B880BF77062458737695A55978269233" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_FBB50BA6BD0FAE352185A55978261DCB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_FBB50BA6BD0FAE352185A55978261DCB" xlink:to="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_FBB50BA6BD0FAE352185A55978261DCB" xlink:to="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_7FF7C7453FBD3AEE24BFA5597826F882" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_7FF7C7453FBD3AEE24BFA5597826F882" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_B0FB8EDA4B4CE914D1DCA55978263BC0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_B0FB8EDA4B4CE914D1DCA55978263BC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_6593FA5B246609682FADA5597826018C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_6593FA5B246609682FADA5597826018C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_656AB5A0860D13196DBCA5597826EC02" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_AFE13E6059014EDD3084A5597826046B" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_656AB5A0860D13196DBCA5597826EC02" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_351E2687EB7360A7BD9BA5597826D379" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_ADE18FEF0FFF1E1E02E4A5597836D4AE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:to="loc_us-gaap_StockholdersEquity_ADE18FEF0FFF1E1E02E4A5597836D4AE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings" xlink:label="loc_iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings_13DDE078D6212EE9B3E6A5597836939C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:to="loc_iart_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarnings_13DDE078D6212EE9B3E6A5597836939C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_E58609919FD9D36F1211A559783692A6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_E58609919FD9D36F1211A559783692A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_34FE719B9E57648F8860A55978366746" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_34FE719B9E57648F8860A55978366746" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_45CCDEA7DBCC5B8B277CA5597836C44E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_D3B6BA70BA23316096E7A5597836801A" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_45CCDEA7DBCC5B8B277CA5597836C44E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/ComprehensiveIncomeScheduleOfComprehensiveIncomeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/ComprehensiveIncomeTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/Debt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DebtContractualMaturityTableDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DebtMaximumTotalLeverageRatioTableDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_2C2F8409457A4B790F52A5597901A632" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_0EDBAF599E27B53AC955A5597901DC56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2C2F8409457A4B790F52A5597901A632" xlink:to="loc_us-gaap_DebtInstrumentTable_0EDBAF599E27B53AC955A5597901DC56" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriodAxis" xlink:label="loc_iart_DebtCovenantPeriodAxis_1AA12A14343D6F06DB76A5597901C795" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_0EDBAF599E27B53AC955A5597901DC56" xlink:to="loc_iart_DebtCovenantPeriodAxis_1AA12A14343D6F06DB76A5597901C795" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriodDomain" xlink:label="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_iart_DebtCovenantPeriodAxis_1AA12A14343D6F06DB76A5597901C795" xlink:to="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4_default" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriodDomain" xlink:label="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_iart_DebtCovenantPeriodAxis_1AA12A14343D6F06DB76A5597901C795" xlink:to="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriod1Member" xlink:label="loc_iart_DebtCovenantPeriod1Member_167F36F0E9AE8059755BA5597901F8CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:to="loc_iart_DebtCovenantPeriod1Member_167F36F0E9AE8059755BA5597901F8CC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriod2Member" xlink:label="loc_iart_DebtCovenantPeriod2Member_86AA526B80A2CADB3116A5597901F3F3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:to="loc_iart_DebtCovenantPeriod2Member_86AA526B80A2CADB3116A5597901F3F3" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriod3Member" xlink:label="loc_iart_DebtCovenantPeriod3Member_A603C4F1CBC584D5DD3BA5597901FD59" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:to="loc_iart_DebtCovenantPeriod3Member_A603C4F1CBC584D5DD3BA5597901FD59" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtCovenantPeriod4Member" xlink:label="loc_iart_DebtCovenantPeriod4Member_C4CF5DF3BDE198CDFC56A55979019A28" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iart_DebtCovenantPeriodDomain_03D89B07CE5830006C8AA5597901D5A4" xlink:to="loc_iart_DebtCovenantPeriod4Member_C4CF5DF3BDE198CDFC56A55979019A28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_97790F11D962A271772BA55979013909" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_0EDBAF599E27B53AC955A5597901DC56" xlink:to="loc_us-gaap_DebtInstrumentAxis_97790F11D962A271772BA55979013909" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_81D7E86DD77E3AFB7F1EA5597901E8E9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_97790F11D962A271772BA55979013909" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_81D7E86DD77E3AFB7F1EA5597901E8E9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_81D7E86DD77E3AFB7F1EA5597901E8E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_97790F11D962A271772BA55979013909" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_81D7E86DD77E3AFB7F1EA5597901E8E9" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SeniorCreditFacilityMember" xlink:label="loc_iart_SeniorCreditFacilityMember_DC16FC085F601B2CA427A5597901F247" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_81D7E86DD77E3AFB7F1EA5597901E8E9" xlink:to="loc_iart_SeniorCreditFacilityMember_DC16FC085F601B2CA427A5597901F247" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DebtInstrumentCovenantMaximumLeverageRatio" xlink:label="loc_iart_DebtInstrumentCovenantMaximumLeverageRatio_9140531884DAEDEBD0A8A5597901BFAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_2C2F8409457A4B790F52A5597901A632" xlink:to="loc_iart_DebtInstrumentCovenantMaximumLeverageRatio_9140531884DAEDEBD0A8A5597901BFAD" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_E5FA4D09164D16392285D158E13863AF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_DebtInstrumentAxis_E5FA4D09164D16392285D158E13863AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_E5FA4D09164D16392285D158E13863AF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_E5FA4D09164D16392285D158E13863AF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TermLoanFacilityMember" xlink:label="loc_iart_TermLoanFacilityMember_7F61701CBD9C067D8CE4D158E1380ABA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:to="loc_iart_TermLoanFacilityMember_7F61701CBD9C067D8CE4D158E1380ABA" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SeniorCreditFacilityMember" xlink:label="loc_iart_SeniorCreditFacilityMember_09E22D4D406102EF66C7D158E13871A1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:to="loc_iart_SeniorCreditFacilityMember_09E22D4D406102EF66C7D158E13871A1" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TermLoanA1Member" xlink:label="loc_iart_TermLoanA1Member_90E1A5852CE0A1C96580D158E1381DBB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:to="loc_iart_TermLoanA1Member_90E1A5852CE0A1C96580D158E1381DBB" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TermLoanAFacilityMember" xlink:label="loc_iart_TermLoanAFacilityMember_E6861B926169A9BD1D1DD158E138EF67" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3C5635DB63E6EA026F11D158E138519D" xlink:to="loc_iart_TermLoanAFacilityMember_E6861B926169A9BD1D1DD158E138EF67" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_A2047A39F002DEAC4942D158E138A8F8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_CreditFacilityAxis_A2047A39F002DEAC4942D158E138A8F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_A2047A39F002DEAC4942D158E138A8F8" xlink:to="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_A2047A39F002DEAC4942D158E138A8F8" xlink:to="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_64DF55F6E98EFD9287BED158E138172E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:to="loc_us-gaap_SecuredDebtMember_64DF55F6E98EFD9287BED158E138172E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_0BC0B5D6B3D7CBFDEF38D158E13857FC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_0BC0B5D6B3D7CBFDEF38D158E13857FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StandbyLettersOfCreditMember" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_8A361BD292BE751D275FD158E13805A3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_8A361BD292BE751D275FD158E13805A3" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SwinglineLoanMember" xlink:label="loc_iart_SwinglineLoanMember_7BF5989D49208CBBA21DD158E138A75E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_663A48D6B908203FDF90D158E1386BAD" xlink:to="loc_iart_SwinglineLoanMember_7BF5989D49208CBBA21DD158E138A75E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_90631A92EF36E5DFA17DD158E138EA29" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_VariableRateAxis_90631A92EF36E5DFA17DD158E138EA29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_90631A92EF36E5DFA17DD158E138EA29" xlink:to="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_90631A92EF36E5DFA17DD158E138EA29" xlink:to="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EurodollarMember" xlink:label="loc_us-gaap_EurodollarMember_2DF5A6F8ADD0FA4F8B53D158E138193C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:to="loc_us-gaap_EurodollarMember_2DF5A6F8ADD0FA4F8B53D158E138193C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FederalFundsEffectiveSwapRateMember" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember_5CAFE7A76A4F9E85CC54D158E1388F4A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:to="loc_us-gaap_FederalFundsEffectiveSwapRateMember_5CAFE7A76A4F9E85CC54D158E1388F4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PrimeRateMember" xlink:label="loc_us-gaap_PrimeRateMember_2CD8971EFE10B035B987D158E138CBF7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:to="loc_us-gaap_PrimeRateMember_2CD8971EFE10B035B987D158E138CBF7" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OneMonthEurodollarRateMember" xlink:label="loc_iart_OneMonthEurodollarRateMember_6F42294D27029C2EADB5D158E138732A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B94B775D86F9FCAE7921D158E1381D76" xlink:to="loc_iart_OneMonthEurodollarRateMember_6F42294D27029C2EADB5D158E138732A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_22F4E0BFEFFEB1515513D158E138430B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_srt_RangeAxis_22F4E0BFEFFEB1515513D158E138430B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_22F4E0BFEFFEB1515513D158E138430B" xlink:to="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_22F4E0BFEFFEB1515513D158E138430B" xlink:to="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_4E25CF2810B4F6D570F4D158E138E6EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72" xlink:to="loc_srt_MinimumMember_4E25CF2810B4F6D570F4D158E138E6EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_F5330C580F2C3872E46BD158E138BD4B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A91758BD350B1F3D593DD158E138CE72" xlink:to="loc_srt_MaximumMember_F5330C580F2C3872E46BD158E138BD4B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_D21A3C93E02FA7E7E9B8D158E1389F25" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_D21A3C93E02FA7E7E9B8D158E1389F25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8624C672746FAE7AB2A1D158E1380BCA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_D21A3C93E02FA7E7E9B8D158E1389F25" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8624C672746FAE7AB2A1D158E1380BCA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8624C672746FAE7AB2A1D158E1380BCA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_D21A3C93E02FA7E7E9B8D158E1389F25" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8624C672746FAE7AB2A1D158E1380BCA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_C349F76A20A76D5790C5D158E138809E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8624C672746FAE7AB2A1D158E1380BCA" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_C349F76A20A76D5790C5D158E138809E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_279B8DECDB8F5B6B5158D158E138D2AB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_HedgingDesignationAxis_279B8DECDB8F5B6B5158D158E138D2AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_165D14D823A61F3EA0F9D158E1381CF8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_279B8DECDB8F5B6B5158D158E138D2AB" xlink:to="loc_us-gaap_HedgingDesignationDomain_165D14D823A61F3EA0F9D158E1381CF8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_165D14D823A61F3EA0F9D158E1381CF8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_279B8DECDB8F5B6B5158D158E138D2AB" xlink:to="loc_us-gaap_HedgingDesignationDomain_165D14D823A61F3EA0F9D158E1381CF8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_FFF2AFFEA3A25E11EC76D158E138D9B3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_165D14D823A61F3EA0F9D158E1381CF8" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_FFF2AFFEA3A25E11EC76D158E138D9B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_653BA6EF5347137E59C4D158E138EA61" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A66F90C4A548D53BB2ED158E1387830" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_653BA6EF5347137E59C4D158E138EA61" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_F974A3A267959338500ED158E138D9CE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_653BA6EF5347137E59C4D158E138EA61" xlink:to="loc_us-gaap_HedgingRelationshipDomain_F974A3A267959338500ED158E138D9CE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_F974A3A267959338500ED158E138D9CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_653BA6EF5347137E59C4D158E138EA61" xlink:to="loc_us-gaap_HedgingRelationshipDomain_F974A3A267959338500ED158E138D9CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_0C7CD6EE10D1520474AED158E13858B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_F974A3A267959338500ED158E138D9CE" xlink:to="loc_us-gaap_CashFlowHedgingMember_0C7CD6EE10D1520474AED158E13858B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_E45741CF1EF9B6543ED3D158E1386F3C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_E45741CF1EF9B6543ED3D158E1386F3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_BC23B2ACA8C60E0470C3D158E138D7D6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_BC23B2ACA8C60E0470C3D158E138D7D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_5161D295BEEBF79FE26BD158E138F544" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_5161D295BEEBF79FE26BD158E138F544" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredFinanceCostsGross" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_7CAF9D0845007D714772D158E1382CC4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_7CAF9D0845007D714772D158E1382CC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_C92E8874107D458A5498D158E1389680" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_C92E8874107D458A5498D158E1389680" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_3CD6D346714954098EC7D158E13856BC" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LineOfCredit_3CD6D346714954098EC7D158E13856BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtWeightedAverageInterestRate" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_142251A3D9E1DCFBD839D158E138DC13" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_142251A3D9E1DCFBD839D158E138DC13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_74489C9E47CF631C0649D158E1382F6C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_74489C9E47CF631C0649D158E1382F6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:label="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_8C9D88021978138F29D6D158E1388D3B" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_8C9D88021978138F29D6D158E1388D3B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_CA7E8D95EC17E28A0BD3D158E138A1D0" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_8F179C87DCD1B731AB78D158E1387720" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_CA7E8D95EC17E28A0BD3D158E138A1D0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DebtTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DefinedBenefitPlans" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DefinedBenefitPlansNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstruments" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsEffectOfDerivativeInstrumentsDesignatedCashFlowHedgesOnStatementsOfOperationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_2E74855356114C12279ED158E10A16CC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_1B70FA29158993AEDFCAD158E10AC3C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_2E74855356114C12279ED158E10A16CC" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_1B70FA29158993AEDFCAD158E10AC3C0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_16A3FC8274746BCEED20D158E10AEB2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_1B70FA29158993AEDFCAD158E10AC3C0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_16A3FC8274746BCEED20D158E10AEB2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_573D7A41C42D56FDF03BD158E10ADC31_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_16A3FC8274746BCEED20D158E10AEB2D" xlink:to="loc_us-gaap_EquityComponentDomain_573D7A41C42D56FDF03BD158E10ADC31_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_573D7A41C42D56FDF03BD158E10ADC31" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_16A3FC8274746BCEED20D158E10AEB2D" xlink:to="loc_us-gaap_EquityComponentDomain_573D7A41C42D56FDF03BD158E10ADC31" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AccumulatedGainLossGrossCashFlowHedgeParentMember" xlink:label="loc_iart_AccumulatedGainLossGrossCashFlowHedgeParentMember_15CC42EDBD73A6A57ADCD199059BC2CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_573D7A41C42D56FDF03BD158E10ADC31" xlink:to="loc_iart_AccumulatedGainLossGrossCashFlowHedgeParentMember_15CC42EDBD73A6A57ADCD199059BC2CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_8AEA439BCD07D78865C9D158E10AF253" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_1B70FA29158993AEDFCAD158E10AC3C0" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_8AEA439BCD07D78865C9D158E10AF253" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8AEA439BCD07D78865C9D158E10AF253" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8AEA439BCD07D78865C9D158E10AF253" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_B8BB320ACD25F239F880D158E10AF6AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727" xlink:to="loc_us-gaap_InterestRateSwapMember_B8BB320ACD25F239F880D158E10AF6AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CrossCurrencyInterestRateContractMember" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_D15A1FF4372A0B2BB9A8D158E10A6071" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7D37E36C816044CEEBC7D158E10A3727" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_D15A1FF4372A0B2BB9A8D158E10A6071" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_158B4DF6B3616A65A405D158E10AE740" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_1B70FA29158993AEDFCAD158E10AC3C0" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_158B4DF6B3616A65A405D158E10AE740" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_158B4DF6B3616A65A405D158E10AE740" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_158B4DF6B3616A65A405D158E10AE740" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="loc_us-gaap_InterestExpenseMember_5CE450A6ED0E27E55F66D158E10A70A8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263" xlink:to="loc_us-gaap_InterestExpenseMember_5CE450A6ED0E27E55F66D158E10A70A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_17363712BC1687FB5949D158E10A8ED0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_411A5CD226ACD17E5A7CD158E10A6263" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_17363712BC1687FB5949D158E10A8ED0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_700E17BE897303155688D158E10A43D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_2E74855356114C12279ED158E10A16CC" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_700E17BE897303155688D158E10A43D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_B084BEDCCC879DBF7151D158E10A9226" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_700E17BE897303155688D158E10A43D5" xlink:to="loc_us-gaap_StockholdersEquity_B084BEDCCC879DBF7151D158E10A9226" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent" xlink:label="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_E26EFD40D8F8B33D51C3D1A2ED5E3994" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_700E17BE897303155688D158E10A43D5" xlink:to="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_E26EFD40D8F8B33D51C3D1A2ED5E3994" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_98DBDA9D28B357A89D46D158E10AC2F6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_700E17BE897303155688D158E10A43D5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_98DBDA9D28B357A89D46D158E10AC2F6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsFairValueOfDerivativeInstrumentsByBalanceSheetLocationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_14CFFF121547E219BFE7A55978B37BB9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_14CFFF121547E219BFE7A55978B37BB9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_78981FD2A2DFD08E8D50A55978B3989B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_14CFFF121547E219BFE7A55978B37BB9" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_78981FD2A2DFD08E8D50A55978B3989B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_78981FD2A2DFD08E8D50A55978B3989B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_78981FD2A2DFD08E8D50A55978B3989B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_86130B8A98E7A022EBC1A55978B3DCCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF" xlink:to="loc_us-gaap_InterestRateSwapMember_86130B8A98E7A022EBC1A55978B3DCCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CrossCurrencyInterestRateContractMember" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_A8287C5095D7792C5A37A55978B39EB1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_CCC4C5C887F7EEFD6886A55978B39FAF" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_A8287C5095D7792C5A37A55978B39EB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_F22215208A6BBC70C119A55978B3AC9D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_14CFFF121547E219BFE7A55978B37BB9" xlink:to="loc_us-gaap_HedgingDesignationAxis_F22215208A6BBC70C119A55978B3AC9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_82FD1D29BF997B9046CFA55978B37E37_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_F22215208A6BBC70C119A55978B3AC9D" xlink:to="loc_us-gaap_HedgingDesignationDomain_82FD1D29BF997B9046CFA55978B37E37_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_82FD1D29BF997B9046CFA55978B37E37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_F22215208A6BBC70C119A55978B3AC9D" xlink:to="loc_us-gaap_HedgingDesignationDomain_82FD1D29BF997B9046CFA55978B37E37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_68380603E02DF3B20575A55978B3E9CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_82FD1D29BF997B9046CFA55978B37E37" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_68380603E02DF3B20575A55978B3E9CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_D22CEC2B57AFB33769F1A55978B37DA7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_14CFFF121547E219BFE7A55978B37BB9" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_D22CEC2B57AFB33769F1A55978B37DA7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_D22CEC2B57AFB33769F1A55978B37DA7" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_D22CEC2B57AFB33769F1A55978B37DA7" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember" xlink:label="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_11821DBD576C3C305652A55978B3731E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:to="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_11821DBD576C3C305652A55978B3731E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_4D2B459C5D7284C03A35A55978B3E899" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:to="loc_us-gaap_OtherAssetsMember_4D2B459C5D7284C03A35A55978B3E899" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AccruedExpensesAndOtherCurrentLiabilitiesMember" xlink:label="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_2295436A909C74A61315A55978B3D152" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:to="loc_iart_AccruedExpensesAndOtherCurrentLiabilitiesMember_2295436A909C74A61315A55978B3D152" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherLiabilitiesMember" xlink:label="loc_us-gaap_OtherLiabilitiesMember_1DD1A54B8F55881F688CA55978B33273" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_8008982E39BF9EEBD0DCA55978B3A560" xlink:to="loc_us-gaap_OtherLiabilitiesMember_1DD1A54B8F55881F688CA55978B33273" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_B93250E78668F5A95B69A55978B3ED2C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_B93250E78668F5A95B69A55978B3ED2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_4D47358931DE30C67F6CA55978B35579" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_4D47358931DE30C67F6CA55978B35579" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_235541FAE63FE5153E81A55978B3F700" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:to="loc_invest_DerivativeNotionalAmount_235541FAE63FE5153E81A55978B3F700" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ReductionInNotionalAmountOfInterestRateDerivativesInNextTwelveMonths" xlink:label="loc_iart_ReductionInNotionalAmountOfInterestRateDerivativesInNextTwelveMonths_C428BF8697C066AEB9E0A55978B34F5C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_2A09DDDAFA0021D16074A55978B328D3" xlink:to="loc_iart_ReductionInNotionalAmountOfInterestRateDerivativesInNextTwelveMonths_C428BF8697C066AEB9E0A55978B34F5C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_9A3F9EE5391FFEBB245BD1E2950DE27C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_9A3F9EE5391FFEBB245BD1E2950DE27C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_9A3F9EE5391FFEBB245BD1E2950DE27C" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_9A3F9EE5391FFEBB245BD1E2950DE27C" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_06641D979BC40ABBE7E0D1E2950D1414" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_06641D979BC40ABBE7E0D1E2950D1414" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CrossCurrencyInterestRateContractMember" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_489E82F67311A9662D22D1E2950D3C26" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5900179535B810D10F03D1E2950D9223" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_489E82F67311A9662D22D1E2950D3C26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_4052F991A35505245677D1E2950D4938" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:to="loc_us-gaap_HedgingDesignationAxis_4052F991A35505245677D1E2950D4938" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_30BBC4BC84FD0425125FD1E2950D3DB1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_4052F991A35505245677D1E2950D4938" xlink:to="loc_us-gaap_HedgingDesignationDomain_30BBC4BC84FD0425125FD1E2950D3DB1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_30BBC4BC84FD0425125FD1E2950D3DB1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_4052F991A35505245677D1E2950D4938" xlink:to="loc_us-gaap_HedgingDesignationDomain_30BBC4BC84FD0425125FD1E2950D3DB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NondesignatedMember" xlink:label="loc_us-gaap_NondesignatedMember_2506B57F74473E4AA14BD1E2950D659A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_30BBC4BC84FD0425125FD1E2950D3DB1" xlink:to="loc_us-gaap_NondesignatedMember_2506B57F74473E4AA14BD1E2950D659A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionAxis" xlink:label="loc_us-gaap_PositionAxis_6B8DE595A2DE21642D2FD1E2950D9960" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:to="loc_us-gaap_PositionAxis_6B8DE595A2DE21642D2FD1E2950D9960" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PositionAxis_6B8DE595A2DE21642D2FD1E2950D9960" xlink:to="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PositionAxis_6B8DE595A2DE21642D2FD1E2950D9960" xlink:to="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_2A0BE20D6AF569B8DD51D1E2950DECC3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8" xlink:to="loc_us-gaap_ShortMember_2A0BE20D6AF569B8DD51D1E2950DECC3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_04355F495278FE96B03AD1E2950D3BC2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_3C871077D943B1423061D1E2950DDEF8" xlink:to="loc_us-gaap_LongMember_04355F495278FE96B03AD1E2950D3BC2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_B0D22D0DE6DD8EA17364D1E2950DA56D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_B0D22D0DE6DD8EA17364D1E2950DA56D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_661C96CA2B4640C63BA1D1E2950D8891_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_B0D22D0DE6DD8EA17364D1E2950DA56D" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_661C96CA2B4640C63BA1D1E2950D8891_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_661C96CA2B4640C63BA1D1E2950D8891" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_B0D22D0DE6DD8EA17364D1E2950DA56D" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_661C96CA2B4640C63BA1D1E2950D8891" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanMember" xlink:label="loc_iart_CodmanMember_7D0A915157B1FBCC6342D1E2950D2FFB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_661C96CA2B4640C63BA1D1E2950D8891" xlink:to="loc_iart_CodmanMember_7D0A915157B1FBCC6342D1E2950D2FFB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_8698EE22347F62199C06D1E2951D2907" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_3294507F00DFF4BAF0B6D1E2950DEB39" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_8698EE22347F62199C06D1E2951D2907" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_B8F8E4CEB4DA965533C1D1E2951DF0F8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8698EE22347F62199C06D1E2951D2907" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_B8F8E4CEB4DA965533C1D1E2951DF0F8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_B8F8E4CEB4DA965533C1D1E2951DF0F8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8698EE22347F62199C06D1E2951D2907" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_B8F8E4CEB4DA965533C1D1E2951DF0F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_C5C8A118EDE6FE5B6718D1E2951DF512" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_B8F8E4CEB4DA965533C1D1E2951DF0F8" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_C5C8A118EDE6FE5B6718D1E2951DF512" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_E0ADB88311472DB79F84D1E2951DADCF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_invest_DerivativeNotionalAmount_E0ADB88311472DB79F84D1E2951DADCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives_7BDE3FE3E70EDB5E8441D1E2951D956E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives_7BDE3FE3E70EDB5E8441D1E2951D956E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_1EB5AD8CAEF6C13FB012D1FDE1AE99A6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_DerivativeAssets_1EB5AD8CAEF6C13FB012D1FDE1AE99A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ChangeInUnrealizedGainLossOnForeignCurrencyFairValueHedgingInstruments1" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnForeignCurrencyFairValueHedgingInstruments1_39AB1300BAAAF4A5805DD1E2951DC743" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnForeignCurrencyFairValueHedgingInstruments1_39AB1300BAAAF4A5805DD1E2951DC743" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_7C9542518BD7E46FB34AD1E2951DC190" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_7C9542518BD7E46FB34AD1E2951DC190" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnDerivativeInstrumentsNetPretax" xlink:label="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_63C8AF580BD76D783A0ED1E2951D1F51" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_GainLossOnDerivativeInstrumentsNetPretax_63C8AF580BD76D783A0ED1E2951D1F51" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_717D1D49EBCD191F4856D1E2951D274C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C4AE6863DD3408672F56D1E2951D7A8A" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_717D1D49EBCD191F4856D1E2951D274C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsScheduleOfCrossCurrencySwapDerivativesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_88C2A7571A256E5590AAA55978C292BA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_88C2A7571A256E5590AAA55978C292BA" xlink:to="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_44BD740BAC4A75913DD7A55978C25968" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_44BD740BAC4A75913DD7A55978C25968" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_30887C6905B8C5B8E658A55978C277F7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_44BD740BAC4A75913DD7A55978C25968" xlink:to="loc_us-gaap_HedgingRelationshipDomain_30887C6905B8C5B8E658A55978C277F7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_30887C6905B8C5B8E658A55978C277F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_44BD740BAC4A75913DD7A55978C25968" xlink:to="loc_us-gaap_HedgingRelationshipDomain_30887C6905B8C5B8E658A55978C277F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_9913F055DEE20104CC08A55978C2E0FD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_30887C6905B8C5B8E658A55978C277F7" xlink:to="loc_us-gaap_CashFlowHedgingMember_9913F055DEE20104CC08A55978C2E0FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5CFBD90CD68FF291848AA55978C21F77" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5CFBD90CD68FF291848AA55978C21F77" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5CFBD90CD68FF291848AA55978C21F77" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_5CFBD90CD68FF291848AA55978C21F77" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SwapOneMember" xlink:label="loc_iart_SwapOneMember_8D27E03261877E9BFF2FA55978C2D663" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D" xlink:to="loc_iart_SwapOneMember_8D27E03261877E9BFF2FA55978C2D663" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SwapTwoMember" xlink:label="loc_iart_SwapTwoMember_CC6E8F222DD0EB565398A55978C275DE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D" xlink:to="loc_iart_SwapTwoMember_CC6E8F222DD0EB565398A55978C275DE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SwapThreeMember" xlink:label="loc_iart_SwapThreeMember_021A71B29FBCC712751CA55978C26C83" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_E63A5275A3157B5B3E24A55978C2D85D" xlink:to="loc_iart_SwapThreeMember_021A71B29FBCC712751CA55978C26C83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_E0128DDEE424BB3463AAA55978C2BD6A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_us-gaap_HedgingDesignationAxis_E0128DDEE424BB3463AAA55978C2BD6A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_C97582CE4A7D4FB0E919A55978C2A656_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_E0128DDEE424BB3463AAA55978C2BD6A" xlink:to="loc_us-gaap_HedgingDesignationDomain_C97582CE4A7D4FB0E919A55978C2A656_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_C97582CE4A7D4FB0E919A55978C2A656" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_E0128DDEE424BB3463AAA55978C2BD6A" xlink:to="loc_us-gaap_HedgingDesignationDomain_C97582CE4A7D4FB0E919A55978C2A656" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_9A5EF600F1575EFD815FA55978C277C8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_C97582CE4A7D4FB0E919A55978C2A656" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_9A5EF600F1575EFD815FA55978C277C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_FC17EF843D3AEB75373BA55978C27251" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_FC17EF843D3AEB75373BA55978C27251" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8E25493B1E71A0433FBDA55978C2233B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC17EF843D3AEB75373BA55978C27251" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8E25493B1E71A0433FBDA55978C2233B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8E25493B1E71A0433FBDA55978C2233B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC17EF843D3AEB75373BA55978C27251" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8E25493B1E71A0433FBDA55978C2233B" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanMember" xlink:label="loc_iart_CodmanMember_771055C55A341E9EF4F6A55978C2088C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8E25493B1E71A0433FBDA55978C2233B" xlink:to="loc_iart_CodmanMember_771055C55A341E9EF4F6A55978C2088C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_A38675D6A8075AEFE710A55978C29763" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_A38675D6A8075AEFE710A55978C29763" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_E86BC73ED3880677170AA55978C2FD5D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_A38675D6A8075AEFE710A55978C29763" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_E86BC73ED3880677170AA55978C2FD5D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_E86BC73ED3880677170AA55978C2FD5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_A38675D6A8075AEFE710A55978C29763" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_E86BC73ED3880677170AA55978C2FD5D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CrossCurrencyInterestRateContractMember" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_9AC6587993086561BD86A55978C242C3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_E86BC73ED3880677170AA55978C2FD5D" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_9AC6587993086561BD86A55978C242C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionAxis" xlink:label="loc_us-gaap_PositionAxis_89925630555EC270879CA55978C2C74D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_8A528EC043AF4B39ED04A55978C24AE6" xlink:to="loc_us-gaap_PositionAxis_89925630555EC270879CA55978C2C74D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PositionAxis_89925630555EC270879CA55978C2C74D" xlink:to="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PositionAxis_89925630555EC270879CA55978C2C74D" xlink:to="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongMember" xlink:label="loc_us-gaap_LongMember_04EC94F9289FC9BD324CA55978C21F4C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827" xlink:to="loc_us-gaap_LongMember_04EC94F9289FC9BD324CA55978C21F4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_42AED6A57C50F9EBDA8DA55978C228B5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_31007B7F107907DD3715A55978C26827" xlink:to="loc_us-gaap_ShortMember_42AED6A57C50F9EBDA8DA55978C228B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_7BAB94B5CE23718CC9EDA55978C29C68" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_88C2A7571A256E5590AAA55978C292BA" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_7BAB94B5CE23718CC9EDA55978C29C68" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_7D185F4EF724980F92B3A55978C269DE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_88C2A7571A256E5590AAA55978C292BA" xlink:to="loc_invest_DerivativeNotionalAmount_7D185F4EF724980F92B3A55978C269DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_93AF11F1507396B88FDEA55978C258DC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_88C2A7571A256E5590AAA55978C292BA" xlink:to="loc_us-gaap_DerivativeLiabilities_93AF11F1507396B88FDEA55978C258DC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsScheduleOfDerivativesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_B7EDAB84A666AFBEA50DA55978F18ECE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_B7EDAB84A666AFBEA50DA55978F18ECE" xlink:to="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_2244D70D22D4F904959AA55978F1C535" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_2244D70D22D4F904959AA55978F1C535" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_EC0E4BC7810290ACCF11A55978F15455_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_2244D70D22D4F904959AA55978F1C535" xlink:to="loc_us-gaap_HedgingRelationshipDomain_EC0E4BC7810290ACCF11A55978F15455_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_EC0E4BC7810290ACCF11A55978F15455" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_2244D70D22D4F904959AA55978F1C535" xlink:to="loc_us-gaap_HedgingRelationshipDomain_EC0E4BC7810290ACCF11A55978F15455" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_A413AEAC5D23B6C52EF6A55978F1A8D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_EC0E4BC7810290ACCF11A55978F15455" xlink:to="loc_us-gaap_CashFlowHedgingMember_A413AEAC5D23B6C52EF6A55978F1A8D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_986B0A899DA3177027DCA55978F1A349" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:to="loc_us-gaap_HedgingDesignationAxis_986B0A899DA3177027DCA55978F1A349" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_DE1E87DFD2B8429273FCA55978F14C7F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_986B0A899DA3177027DCA55978F1A349" xlink:to="loc_us-gaap_HedgingDesignationDomain_DE1E87DFD2B8429273FCA55978F14C7F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_DE1E87DFD2B8429273FCA55978F14C7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_986B0A899DA3177027DCA55978F1A349" xlink:to="loc_us-gaap_HedgingDesignationDomain_DE1E87DFD2B8429273FCA55978F14C7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_69E0515B0A7CE3261967A55978F17E5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_DE1E87DFD2B8429273FCA55978F14C7F" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_69E0515B0A7CE3261967A55978F17E5D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_C572EC81B64ADBCA0057A55978F1FB72" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:to="loc_us-gaap_VariableRateAxis_C572EC81B64ADBCA0057A55978F1FB72" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_C572EC81B64ADBCA0057A55978F1FB72" xlink:to="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_C572EC81B64ADBCA0057A55978F1FB72" xlink:to="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ThreeMonthUSDLIBORMember" xlink:label="loc_iart_ThreeMonthUSDLIBORMember_60CF133FEB82CBBD4490A55978F1B70C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550" xlink:to="loc_iart_ThreeMonthUSDLIBORMember_60CF133FEB82CBBD4490A55978F1B70C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OneMonthUSDLIBORMember" xlink:label="loc_iart_OneMonthUSDLIBORMember_0251C4D47FC45AF173AAA55978F1A38B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B2B9C7187FC6556D5B7FA55978F18550" xlink:to="loc_iart_OneMonthUSDLIBORMember_0251C4D47FC45AF173AAA55978F1A38B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_9346A8ECF81AA1F66381A55978F10A2E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_E501865F02E2D86AF05CA55978F1652D" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_9346A8ECF81AA1F66381A55978F10A2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_9346A8ECF81AA1F66381A55978F10A2E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_9346A8ECF81AA1F66381A55978F10A2E" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedJune222016Tranche1Member" xlink:label="loc_iart_InterestRateSwapDesignatedJune222016Tranche1Member_F3103425847AA1EF4A7FA55978F12F78" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedJune222016Tranche1Member_F3103425847AA1EF4A7FA55978F12F78" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedJune222016Tranche2Member" xlink:label="loc_iart_InterestRateSwapDesignatedJune222016Tranche2Member_A283EB5E30D65879C4C4A55978F10836" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedJune222016Tranche2Member_A283EB5E30D65879C4C4A55978F10836" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedJuly122016Member" xlink:label="loc_iart_InterestRateSwapDesignatedJuly122016Member_649062915DA7531E678FA55978F18716" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedJuly122016Member_649062915DA7531E678FA55978F18716" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedFebruary62017Tranche1Member" xlink:label="loc_iart_InterestRateSwapDesignatedFebruary62017Tranche1Member_8E661704FC19DA1233F4A55978F1CB87" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedFebruary62017Tranche1Member_8E661704FC19DA1233F4A55978F1CB87" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedFebruary62017Tranche2Member" xlink:label="loc_iart_InterestRateSwapDesignatedFebruary62017Tranche2Member_021776447EA745B0EAABA55978F16373" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedFebruary62017Tranche2Member_021776447EA745B0EAABA55978F16373" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedMarch272017Member" xlink:label="loc_iart_InterestRateSwapDesignatedMarch272017Member_AB671411A7AB00DE1FBDA55978F1192C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedMarch272017Member_AB671411A7AB00DE1FBDA55978F1192C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedDecember132017Tranche1Member" xlink:label="loc_iart_InterestRateSwapDesignatedDecember132017Tranche1Member_7C12D880F05A72F59888A55978F118F1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedDecember132017Tranche1Member_7C12D880F05A72F59888A55978F118F1" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedDecember132017Tranche2Member" xlink:label="loc_iart_InterestRateSwapDesignatedDecember132017Tranche2Member_4691DFA09B8D0E00D260A55978F1C2E1" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedDecember132017Tranche2Member_4691DFA09B8D0E00D260A55978F1C2E1" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedDecember132017Tranche3Member" xlink:label="loc_iart_InterestRateSwapDesignatedDecember132017Tranche3Member_1273766FC55CF79DE648A55978F13441" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedDecember132017Tranche3Member_1273766FC55CF79DE648A55978F13441" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedDecember132017Tranche4Member" xlink:label="loc_iart_InterestRateSwapDesignatedDecember132017Tranche4Member_48EA8670A032ABC78C44A55978F17425" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedDecember132017Tranche4Member_48EA8670A032ABC78C44A55978F17425" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InterestRateSwapDesignatedDecember132017Tranche5Member" xlink:label="loc_iart_InterestRateSwapDesignatedDecember132017Tranche5Member_D41D351257C84CC6EB19A55978F1EEEA" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_B007D5423D6AB9BC0090A55978F13AB7" xlink:to="loc_iart_InterestRateSwapDesignatedDecember132017Tranche5Member_D41D351257C84CC6EB19A55978F1EEEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_3EED2B35246B3F7B998FA55978F1C4C4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_B7EDAB84A666AFBEA50DA55978F18ECE" xlink:to="loc_invest_DerivativeNotionalAmount_3EED2B35246B3F7B998FA55978F1C4C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_E9EF223D21ECE041644AA55978F11E43" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_B7EDAB84A666AFBEA50DA55978F18ECE" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_E9EF223D21ECE041644AA55978F11E43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_2D318319E21862A23C0BA55978F1D538" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_B7EDAB84A666AFBEA50DA55978F18ECE" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_2D318319E21862A23C0BA55978F1D538" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/DerivativeInstrumentsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/GoodwillAndOtherIntangibleAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsComponentsOfCompanysIdentifiableIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_93FE6861BC38FAC890C3CD0EFD3FB5DD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_93FE6861BC38FAC890C3CD0EFD3FB5DD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_97DC57858AF914F0B175CD0EFD40FB91" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_93FE6861BC38FAC890C3CD0EFD3FB5DD" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_97DC57858AF914F0B175CD0EFD40FB91" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_97DC57858AF914F0B175CD0EFD40FB91" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_97DC57858AF914F0B175CD0EFD40FB91" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CompletedTechnologyMember" xlink:label="loc_iart_CompletedTechnologyMember_FDB074D4141BCC024B87CD0EFD400DB4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:to="loc_iart_CompletedTechnologyMember_FDB074D4141BCC024B87CD0EFD400DB4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_022287A22D020BE8B620CD0EFD412E94" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:to="loc_us-gaap_CustomerRelationshipsMember_022287A22D020BE8B620CD0EFD412E94" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TrademarksBrandNamesMember" xlink:label="loc_iart_TrademarksBrandNamesMember_14B844335BB6DFD9B2FDCD0EFD4114E5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:to="loc_iart_TrademarksBrandNamesMember_14B844335BB6DFD9B2FDCD0EFD4114E5" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SupplierRelationShipsMember" xlink:label="loc_iart_SupplierRelationShipsMember_95E20CDA25F35989C5BFCD0EFD413685" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:to="loc_iart_SupplierRelationShipsMember_95E20CDA25F35989C5BFCD0EFD413685" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_AllOtherMember" xlink:label="loc_iart_AllOtherMember_97A35874BA55612A8FF7CD0EFD41E638" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_EEE75B2DCB0B353838C7CD0EFD40EABC" xlink:to="loc_iart_AllOtherMember_97A35874BA55612A8FF7CD0EFD41E638" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_5C7B93D01DF71A2CB5B9CD0EFD422DA3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_93FE6861BC38FAC890C3CD0EFD3FB5DD" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_5C7B93D01DF71A2CB5B9CD0EFD422DA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_5C7B93D01DF71A2CB5B9CD0EFD422DA3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_5C7B93D01DF71A2CB5B9CD0EFD422DA3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_0B43F9DAB7733434BD51CD0EFD42DE22" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE" xlink:to="loc_us-gaap_TradeNamesMember_0B43F9DAB7733434BD51CD0EFD42DE22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InProcessResearchAndDevelopmentMember" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_3479B6CEFBCA44A9B761CD0EFD437031" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5AFE41483E48F548ADA2CD0EFD42ECFE" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_3479B6CEFBCA44A9B761CD0EFD437031" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_01DF12ED212E8F5BFD2DCD0EFD4305C8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_01DF12ED212E8F5BFD2DCD0EFD4305C8" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CostOfDefiniteAndIndefiniteLivedIntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_iart_CostOfDefiniteAndIndefiniteLivedIntangibleAssetsGrossExcludingGoodwill_C05AABC474822CCD9700CD0EFD43E2B1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_iart_CostOfDefiniteAndIndefiniteLivedIntangibleAssetsGrossExcludingGoodwill_C05AABC474822CCD9700CD0EFD43E2B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_C6EAE4B7FA711760478ECD0EFD43C09B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_C6EAE4B7FA711760478ECD0EFD43C09B" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DefiniteAndIndefiniteLivedIntangibleAssetsNetExcludingGoodwill" xlink:label="loc_iart_DefiniteAndIndefiniteLivedIntangibleAssetsNetExcludingGoodwill_D59CCFEB9F89721479C4CD0EFD44738F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_iart_DefiniteAndIndefiniteLivedIntangibleAssetsNetExcludingGoodwill_D59CCFEB9F89721479C4CD0EFD44738F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherIndefiniteLivedIntangibleAssets" xlink:label="loc_us-gaap_OtherIndefiniteLivedIntangibleAssets_5F82559960B56D100BBFCD0EFD44A349" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_4588D81AA0FF420976FBCD0EFD43F030" xlink:to="loc_us-gaap_OtherIndefiniteLivedIntangibleAssets_5F82559960B56D100BBFCD0EFD44A349" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_16FC765FF135E65EE32DA559793F1558" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_16FC765FF135E65EE32DA559793F1558" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_17647F11EB820340D824A559793FA1D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_16FC765FF135E65EE32DA559793F1558" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_17647F11EB820340D824A559793FA1D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3B9180C33E8A3679F8BCA559793FBAD9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_17647F11EB820340D824A559793FA1D1" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3B9180C33E8A3679F8BCA559793FBAD9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3B9180C33E8A3679F8BCA559793FBAD9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_17647F11EB820340D824A559793FA1D1" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3B9180C33E8A3679F8BCA559793FBAD9" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TarsusMedicalInc.Member" xlink:label="loc_iart_TarsusMedicalInc.Member_90C9A671BD7A895395D5A559793F092F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3B9180C33E8A3679F8BCA559793FBAD9" xlink:to="loc_iart_TarsusMedicalInc.Member_90C9A671BD7A895395D5A559793F092F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_823E001FEAC34C7EDF1CA559793F22B1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_16FC765FF135E65EE32DA559793F1558" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_823E001FEAC34C7EDF1CA559793F22B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_8C8951491EA556ECDEB4A559793F32BA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_823E001FEAC34C7EDF1CA559793F22B1" xlink:to="loc_us-gaap_SegmentDomain_8C8951491EA556ECDEB4A559793F32BA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_8C8951491EA556ECDEB4A559793F32BA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_823E001FEAC34C7EDF1CA559793F22B1" xlink:to="loc_us-gaap_SegmentDomain_8C8951491EA556ECDEB4A559793F32BA" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OrthopedicsandTissueTechnologiesMember" xlink:label="loc_iart_OrthopedicsandTissueTechnologiesMember_8F2B8B6A8F855A6FE9ACA559793FDDF3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8C8951491EA556ECDEB4A559793F32BA" xlink:to="loc_iart_OrthopedicsandTissueTechnologiesMember_8F2B8B6A8F855A6FE9ACA559793FDDF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_512316005F0F306054B9A559793FBE6E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_512316005F0F306054B9A559793FBE6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_024E0DC79CD2D62DE2ADA559793FEF25" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_024E0DC79CD2D62DE2ADA559793FEF25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_A599B36B59CE5F5224F8A559793F04A3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_A599B36B59CE5F5224F8A559793F04A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_C211D8EAD93F7B7156AEA559793F8889" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_C211D8EAD93F7B7156AEA559793F8889" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_9F90DB75B6CAD61934E4A559793F2315" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_9F90DB75B6CAD61934E4A559793F2315" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_542FC3EBE7A219096EEDA559793F4866" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_542FC3EBE7A219096EEDA559793F4866" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FiniteLivedIntangibleAssetsAmortizationExpenseYearSix" xlink:label="loc_iart_FiniteLivedIntangibleAssetsAmortizationExpenseYearSix_76277BC7F368C0F02F46A559793F7611" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_iart_FiniteLivedIntangibleAssetsAmortizationExpenseYearSix_76277BC7F368C0F02F46A559793F7611" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearSix" xlink:label="loc_iart_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearSix_2CC50FD9ADE79906123FA559793F4A7E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_4E3F2E9F1E3A81107389A559793F6064" xlink:to="loc_iart_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearSix_2CC50FD9ADE79906123FA559793F4A7E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfChangesInCarryingAmountOfGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_FF5ABD2333B62BA7FC97A559794F9961" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_6998D11EAEB8C9057662A559794FE100" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_FF5ABD2333B62BA7FC97A559794F9961" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_6998D11EAEB8C9057662A559794FE100" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1505E4699668EC878285A559794FA4B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_6998D11EAEB8C9057662A559794FE100" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1505E4699668EC878285A559794FA4B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1505E4699668EC878285A559794FA4B6" xlink:to="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1505E4699668EC878285A559794FA4B6" xlink:to="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_CD8553B38BDDD6B418A2A559794F430C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_CD8553B38BDDD6B418A2A559794F430C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OrthopedicsandTissueTechnologiesMember" xlink:label="loc_iart_OrthopedicsandTissueTechnologiesMember_F449F6C940CAEC311BDCA559794F337C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9C3FBC88E93883A4EC86A559794F59D6" xlink:to="loc_iart_OrthopedicsandTissueTechnologiesMember_F449F6C940CAEC311BDCA559794F337C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2AD6FD12F26F9312A85AA559794F1E29" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_6998D11EAEB8C9057662A559794FE100" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2AD6FD12F26F9312A85AA559794F1E29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3E8FB0D6FD6895C41A46A559794F60A3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2AD6FD12F26F9312A85AA559794F1E29" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3E8FB0D6FD6895C41A46A559794F60A3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3E8FB0D6FD6895C41A46A559794F60A3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2AD6FD12F26F9312A85AA559794F1E29" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3E8FB0D6FD6895C41A46A559794F60A3" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanMember" xlink:label="loc_iart_CodmanMember_C5905BF8BF65A2186A1BA559794F00EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3E8FB0D6FD6895C41A46A559794F60A3" xlink:to="loc_iart_CodmanMember_C5905BF8BF65A2186A1BA559794F00EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_463FA149AD50A215CF0BA559794F3740" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_FF5ABD2333B62BA7FC97A559794F9961" xlink:to="loc_us-gaap_GoodwillRollForward_463FA149AD50A215CF0BA559794F3740" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_7E19A16EE8ACBFE23E72A559794F6C94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_463FA149AD50A215CF0BA559794F3740" xlink:to="loc_us-gaap_Goodwill_7E19A16EE8ACBFE23E72A559794F6C94" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_FB67E60A13529EBDD622A559794F2800" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_463FA149AD50A215CF0BA559794F3740" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_FB67E60A13529EBDD622A559794F2800" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1466A268E1D2580DE34CA559794F98E7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_463FA149AD50A215CF0BA559794F3740" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1466A268E1D2580DE34CA559794F98E7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/IncomeTaxes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/IncomeTaxesSummaryOfEffectiveTaxRateDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/IncomeTaxesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/Inventories" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/InventoriesScheduleOfNetInventoriesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/InventoriesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/NetIncomePerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/NetIncomePerShareBasicAndDilutedNetIncomePerShareDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/NetIncomePerShareNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_64F1933DBEBDB3465E2DA559784637C4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_64F1933DBEBDB3465E2DA559784637C4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_9151F35595C29CD13F61A5597846AD5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_64F1933DBEBDB3465E2DA559784637C4" xlink:to="loc_us-gaap_DebtInstrumentAxis_9151F35595C29CD13F61A5597846AD5F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_03D760AD96A42827AB13A55978460423_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_9151F35595C29CD13F61A5597846AD5F" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_03D760AD96A42827AB13A55978460423_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_03D760AD96A42827AB13A55978460423" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_9151F35595C29CD13F61A5597846AD5F" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_03D760AD96A42827AB13A55978460423" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_TwoThousandSixteenSeniorConvertibleNotesMember" xlink:label="loc_iart_TwoThousandSixteenSeniorConvertibleNotesMember_90E25413AB88B8697704A5597846B4C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_03D760AD96A42827AB13A55978460423" xlink:to="loc_iart_TwoThousandSixteenSeniorConvertibleNotesMember_90E25413AB88B8697704A5597846B4C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_AB896D9CCD9D8BE1CFF1A5597846FE21" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_64F1933DBEBDB3465E2DA559784637C4" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_AB896D9CCD9D8BE1CFF1A5597846FE21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_235018FAE8F487DF959EA55978463000_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_AB896D9CCD9D8BE1CFF1A5597846FE21" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_235018FAE8F487DF959EA55978463000_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_235018FAE8F487DF959EA55978463000" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_AB896D9CCD9D8BE1CFF1A5597846FE21" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_235018FAE8F487DF959EA55978463000" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConvertibleDebtMember" xlink:label="loc_us-gaap_ConvertibleDebtMember_C0238AC3D51C2EB63586A55978466767" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_235018FAE8F487DF959EA55978463000" xlink:to="loc_us-gaap_ConvertibleDebtMember_C0238AC3D51C2EB63586A55978466767" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_CE5D2C47DB9B38D1B7B5A5597846108A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_64F1933DBEBDB3465E2DA559784637C4" xlink:to="loc_us-gaap_AwardTypeAxis_CE5D2C47DB9B38D1B7B5A5597846108A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_F74E5D11DC623E39E72BA5597846267B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_CE5D2C47DB9B38D1B7B5A5597846108A" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_F74E5D11DC623E39E72BA5597846267B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_F74E5D11DC623E39E72BA5597846267B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_CE5D2C47DB9B38D1B7B5A5597846108A" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_F74E5D11DC623E39E72BA5597846267B" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_PerformanceSharesandRestrictedUnitsMember" xlink:label="loc_iart_PerformanceSharesandRestrictedUnitsMember_847005380A4328FA169CA55978461312" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_F74E5D11DC623E39E72BA5597846267B" xlink:to="loc_iart_PerformanceSharesandRestrictedUnitsMember_847005380A4328FA169CA55978461312" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_BA4A718658DBBE8D2A7BA5597846CEFA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_BA4A718658DBBE8D2A7BA5597846CEFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_88910F13CD301CBE6708A5597846465D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_88910F13CD301CBE6708A5597846465D" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ClassofWarrantorRightExercised" xlink:label="loc_iart_ClassofWarrantorRightExercised_D486BF5C8D9359B0A185A559784635BE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_iart_ClassofWarrantorRightExercised_D486BF5C8D9359B0A185A559784635BE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_StockIssuedDuringPeriodSharesExerciseOfWarrants" xlink:label="loc_iart_StockIssuedDuringPeriodSharesExerciseOfWarrants_34F1428A3B972EDBDB3FA5597846064A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_iart_StockIssuedDuringPeriodSharesExerciseOfWarrants_34F1428A3B972EDBDB3FA5597846064A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_038023A08A292716396AA559784660CC" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_038023A08A292716396AA559784660CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_9EF7171C1C6C9D62DAD0A5597846F9CB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_77C31BAC0E1D2B68F43FA55978460777" xlink:to="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_9EF7171C1C6C9D62DAD0A5597846F9CB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/NetIncomePerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomers" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersImpactOfAdoptionOnStatementOfOperationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_320475DBD33ED713BC65B7B2535BAC32" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_5CD4CEFD5CA1AC0BCE29B7B2535B2994" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_320475DBD33ED713BC65B7B2535BAC32" xlink:to="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_5CD4CEFD5CA1AC0BCE29B7B2535B2994" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_509441C45A38E37F1092B7B2535B5DD0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_5CD4CEFD5CA1AC0BCE29B7B2535B2994" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_509441C45A38E37F1092B7B2535B5DD0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_72504F01078BBBA7CCEBB7B2535B2C8B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_509441C45A38E37F1092B7B2535B5DD0" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_72504F01078BBBA7CCEBB7B2535B2C8B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_72504F01078BBBA7CCEBB7B2535B2C8B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_509441C45A38E37F1092B7B2535B5DD0" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_72504F01078BBBA7CCEBB7B2535B2C8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member" xlink:label="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_245385C9BA7BF1C51CE5B7B2535B6649" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_72504F01078BBBA7CCEBB7B2535B2C8B" xlink:to="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_245385C9BA7BF1C51CE5B7B2535B6649" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_320475DBD33ED713BC65B7B2535BAC32" xlink:to="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0681FEDDAA3DCE09D801B7B2535BAB71" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0681FEDDAA3DCE09D801B7B2535BAB71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_8062FC39BB916614717DB7B2535B42D9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_8062FC39BB916614717DB7B2535B42D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_7E509C9A883709389CFCB7B2535BFD58" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_7E509C9A883709389CFCB7B2535BFD58" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_AC09C11F75195F851A3AB7B2535B15E2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract_21F51C1AE9A6ACCFA164B7B2535B736A" xlink:to="loc_us-gaap_NetIncomeLoss_AC09C11F75195F851A3AB7B2535B15E2" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_290548F8EC1459B02AC4A559798DB5C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:to="loc_srt_RangeAxis_290548F8EC1459B02AC4A559798DB5C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_290548F8EC1459B02AC4A559798DB5C9" xlink:to="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_290548F8EC1459B02AC4A559798DB5C9" xlink:to="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_9868126FB14A45F98860A559798DAB32" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74" xlink:to="loc_srt_MinimumMember_9868126FB14A45F98860A559798DAB32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_1CEB1E2C542736E11275A559798DF8E3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0E2FDD783565B4657EB4A559798DEF74" xlink:to="loc_srt_MaximumMember_1CEB1E2C542736E11275A559798DF8E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_AC508F77A07D282BC47EA559798DF2D8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_AC508F77A07D282BC47EA559798DF2D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_F5389B57343F191CB183A559798DFAC4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_AC508F77A07D282BC47EA559798DF2D8" xlink:to="loc_us-gaap_TypeOfAdoptionMember_F5389B57343F191CB183A559798DFAC4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_F5389B57343F191CB183A559798DFAC4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_AC508F77A07D282BC47EA559798DF2D8" xlink:to="loc_us-gaap_TypeOfAdoptionMember_F5389B57343F191CB183A559798DFAC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_E22C418F76203013CED0A559798DFDE2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_F5389B57343F191CB183A559798DFAC4" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_E22C418F76203013CED0A559798DFDE2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_5B13F5E3CD7AA74276D8A559798DBA9F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_5B13F5E3CD7AA74276D8A559798DBA9F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_5ACDD768E7CE3F3C4398A559798DC4DA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_5B13F5E3CD7AA74276D8A559798DBA9F" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_5ACDD768E7CE3F3C4398A559798DC4DA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_5ACDD768E7CE3F3C4398A559798DC4DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_5B13F5E3CD7AA74276D8A559798DBA9F" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_5ACDD768E7CE3F3C4398A559798DC4DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member" xlink:label="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_A2902E488AAD463D0FF5A559798DCB6E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_5ACDD768E7CE3F3C4398A559798DC4DA" xlink:to="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_A2902E488AAD463D0FF5A559798DCB6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_8AACB204DE658392C7F2A559798DBBD5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_8AACB204DE658392C7F2A559798DBBD5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_72C09AA775854CF92AE5A559798DEDD3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_8AACB204DE658392C7F2A559798DBBD5" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_72C09AA775854CF92AE5A559798DEDD3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_72C09AA775854CF92AE5A559798DEDD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_8AACB204DE658392C7F2A559798DBBD5" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_72C09AA775854CF92AE5A559798DEDD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TransferredOverTimeMember" xlink:label="loc_us-gaap_TransferredOverTimeMember_1209F5C3DB24C5784557A559798DAAAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_72C09AA775854CF92AE5A559798DEDD3" xlink:to="loc_us-gaap_TransferredOverTimeMember_1209F5C3DB24C5784557A559798DAAAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_E1677C97DC4D57958057A559798D7199" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_2A9F975488A8C0A225F8A559798D0C2D" xlink:to="loc_srt_ProductOrServiceAxis_E1677C97DC4D57958057A559798D7199" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_44A0243E0ABED456FBDEA559798D9D31_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_E1677C97DC4D57958057A559798D7199" xlink:to="loc_srt_ProductsAndServicesDomain_44A0243E0ABED456FBDEA559798D9D31_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_44A0243E0ABED456FBDEA559798D9D31" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_E1677C97DC4D57958057A559798D7199" xlink:to="loc_srt_ProductsAndServicesDomain_44A0243E0ABED456FBDEA559798D9D31" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_PrivateLabelMember" xlink:label="loc_iart_PrivateLabelMember_88F594585CA097B05279A559798DA028" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_44A0243E0ABED456FBDEA559798D9D31" xlink:to="loc_iart_PrivateLabelMember_88F594585CA097B05279A559798DA028" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_RevenueFromContractWithCustomerProductsShippedWithNoAlternativeUseAndRightOfPaymentForPerformanceManufacturingPeriod" xlink:label="loc_iart_RevenueFromContractWithCustomerProductsShippedWithNoAlternativeUseAndRightOfPaymentForPerformanceManufacturingPeriod_39C8EC357DECFF374630A559798D212C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_iart_RevenueFromContractWithCustomerProductsShippedWithNoAlternativeUseAndRightOfPaymentForPerformanceManufacturingPeriod_39C8EC357DECFF374630A559798D212C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ReturnPolicyIssueofCreditNumberofDaysfromShipment" xlink:label="loc_iart_ReturnPolicyIssueofCreditNumberofDaysfromShipment_C7E7D333F84E545216B4A559798D6139" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_iart_ReturnPolicyIssueofCreditNumberofDaysfromShipment_C7E7D333F84E545216B4A559798D6139" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_1B8D821642E033142327A559798D6FF8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_1B8D821642E033142327A559798D6FF8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_56F2819FABDEB0BA50C6A559798D9DCE" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_56F2819FABDEB0BA50C6A559798D9DCE" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_RevenueProductWarrantyPeriod" xlink:label="loc_iart_RevenueProductWarrantyPeriod_7AC0E3EA79FC51CB588EA559798DF88F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_iart_RevenueProductWarrantyPeriod_7AC0E3EA79FC51CB588EA559798DF88F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_F2D524C546A00AE90070A559798D4919" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_F2D524C546A00AE90070A559798D4919" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_8FAD64838725D15B09BCA559798DB7BA" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_Assets_8FAD64838725D15B09BCA559798DB7BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_7E5B31C9AA6EDE7C4D3AA559798DFEA3" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_6C63AA462346891EC23EA559798DEBB9" xlink:to="loc_us-gaap_Liabilities_7E5B31C9AA6EDE7C4D3AA559798DFEA3" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersNarrativeRevenueRemainingPerformanceObligationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_F566A2A59103783776A8A559798D6EF3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_B5BFE01C96820560A26FA559798DDED0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_F566A2A59103783776A8A559798D6EF3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_B5BFE01C96820560A26FA559798DDED0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_B5475AB453261CE5D817A559798D98D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_B5BFE01C96820560A26FA559798DDED0" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_B5475AB453261CE5D817A559798D98D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_2BD899CB3CD20B940693A559798D6D5A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_F566A2A59103783776A8A559798D6EF3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_2BD899CB3CD20B940693A559798D6D5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_778FB1A75311F802BA79A559798D4244" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_F566A2A59103783776A8A559798D6EF3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_778FB1A75311F802BA79A559798D4244" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersScheduleOfChangesInContractAssetsAndLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersScheduleOfRevenuesDisaggregatedByMajorSourceDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_5F72B5256C51BE4F36D8D1E29566E8C6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_E027832BFFDB7EE30767D1E295663A8D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_5F72B5256C51BE4F36D8D1E29566E8C6" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_E027832BFFDB7EE30767D1E295663A8D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_D7AA3E02B7A8F78C12F1D1E29566BAD9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_E027832BFFDB7EE30767D1E295663A8D" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_D7AA3E02B7A8F78C12F1D1E29566BAD9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_D7AA3E02B7A8F78C12F1D1E29566BAD9" xlink:to="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_D7AA3E02B7A8F78C12F1D1E29566BAD9" xlink:to="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_FA49A98952C7680EE67ED1E29566847A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_FA49A98952C7680EE67ED1E29566847A" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OrthopedicsandTissueTechnologiesMember" xlink:label="loc_iart_OrthopedicsandTissueTechnologiesMember_BCDF4465112D02AFF9DAD1E29566EE36" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_E22769D8CEB34FB51974D1E29566D321" xlink:to="loc_iart_OrthopedicsandTissueTechnologiesMember_BCDF4465112D02AFF9DAD1E29566EE36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_A9C93003598DB0A9C12ED1E29566DCCE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_E027832BFFDB7EE30767D1E295663A8D" xlink:to="loc_srt_ProductOrServiceAxis_A9C93003598DB0A9C12ED1E29566DCCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_A9C93003598DB0A9C12ED1E29566DCCE" xlink:to="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_A9C93003598DB0A9C12ED1E29566DCCE" xlink:to="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_NeurosurgeryMember" xlink:label="loc_iart_NeurosurgeryMember_2306F12C6B4C1C457AE3D1E2956682CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:to="loc_iart_NeurosurgeryMember_2306F12C6B4C1C457AE3D1E2956682CB" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_InstrumentsMember" xlink:label="loc_iart_InstrumentsMember_FB43762C4D1239E03A4CD1E295661F14" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:to="loc_iart_InstrumentsMember_FB43762C4D1239E03A4CD1E295661F14" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_RegenerativeSkinAndWoundMember" xlink:label="loc_iart_RegenerativeSkinAndWoundMember_C8E183FEF9EE07E57502D1E295665650" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:to="loc_iart_RegenerativeSkinAndWoundMember_C8E183FEF9EE07E57502D1E295665650" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ExtremityOrthopedicsMember" xlink:label="loc_iart_ExtremityOrthopedicsMember_13D3447404D24F514144D1E29566973C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:to="loc_iart_ExtremityOrthopedicsMember_13D3447404D24F514144D1E29566973C" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_PrivateLabelMember" xlink:label="loc_iart_PrivateLabelMember_05B0C59ADE93792C883CD1E29566B60D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_AF109010F18B81D91A5BD1E295664E96" xlink:to="loc_iart_PrivateLabelMember_05B0C59ADE93792C883CD1E29566B60D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_78CC53E7F7A750E94001D1E29566B033" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_5F72B5256C51BE4F36D8D1E29566E8C6" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_78CC53E7F7A750E94001D1E29566B033" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/RevenuesFromContractsWithCustomersTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/SegmentAndGeographicInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/SegmentAndGeographicInformationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_8DEA05AC0668FFE1C793A5597817FDE8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2B3AE4FBC99DDC2D664FA5597817418A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8DEA05AC0668FFE1C793A5597817FDE8" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2B3AE4FBC99DDC2D664FA5597817418A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_37034F7228E3D1741606A55978178E13" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_2B3AE4FBC99DDC2D664FA5597817418A" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_37034F7228E3D1741606A55978178E13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_53540DCB98080870F7BEA55978172213_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_37034F7228E3D1741606A55978178E13" xlink:to="loc_us-gaap_SegmentDomain_53540DCB98080870F7BEA55978172213_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_53540DCB98080870F7BEA55978172213" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_37034F7228E3D1741606A55978178E13" xlink:to="loc_us-gaap_SegmentDomain_53540DCB98080870F7BEA55978172213" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_037595FA678AAB9AEA56A55978172420" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_53540DCB98080870F7BEA55978172213" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_037595FA678AAB9AEA56A55978172420" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="loc_us-gaap_NumberOfReportableSegments_FA70331BCED17B93B121A55978176191" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8DEA05AC0668FFE1C793A5597817FDE8" xlink:to="loc_us-gaap_NumberOfReportableSegments_FA70331BCED17B93B121A55978176191" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_SegmentReportingInformationNumberofProductsOffered" xlink:label="loc_iart_SegmentReportingInformationNumberofProductsOffered_BD7285168D644E060B37A5597817040E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8DEA05AC0668FFE1C793A5597817FDE8" xlink:to="loc_iart_SegmentReportingInformationNumberofProductsOffered_BD7285168D644E060B37A5597817040E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/SegmentAndGeographicInformationNetSalesAndProfitByReportableSegmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_0A0F5714D146EE510FCEA5597807743F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FCE0348ED78FE38AAD7BA55978079A24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0A0F5714D146EE510FCEA5597807743F" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FCE0348ED78FE38AAD7BA55978079A24" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_AFDF243FFB0D5530B070A5597807FDC4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FCE0348ED78FE38AAD7BA55978079A24" xlink:to="loc_srt_ConsolidationItemsAxis_AFDF243FFB0D5530B070A5597807FDC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_AFDF243FFB0D5530B070A5597807FDC4" xlink:to="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_AFDF243FFB0D5530B070A5597807FDC4" xlink:to="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_261C7A33FE9EF9C3BEABA559780795D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F" xlink:to="loc_us-gaap_OperatingSegmentsMember_261C7A33FE9EF9C3BEABA559780795D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MaterialReconcilingItemsMember" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_06ED939EEBD042515AC5A55978076980" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_06ED939EEBD042515AC5A55978076980" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_3CFFF3AFA065D950A366A559780759A9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_283A9CE3E1E4282D5807A5597807BB1F" xlink:to="loc_us-gaap_CorporateNonSegmentMember_3CFFF3AFA065D950A366A559780759A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_D4070B7FA581004F9614A5597807DD5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_FCE0348ED78FE38AAD7BA55978079A24" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_D4070B7FA581004F9614A5597807DD5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_D4070B7FA581004F9614A5597807DD5C" xlink:to="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_D4070B7FA581004F9614A5597807DD5C" xlink:to="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_CodmanSpecialtySurgicalMember" xlink:label="loc_iart_CodmanSpecialtySurgicalMember_AD6A8EAB2BB4C60FA533A55978077522" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58" xlink:to="loc_iart_CodmanSpecialtySurgicalMember_AD6A8EAB2BB4C60FA533A55978077522" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_OrthopedicsandTissueTechnologiesMember" xlink:label="loc_iart_OrthopedicsandTissueTechnologiesMember_ED414F848BE59D9C0664A5597807FE6B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_463CF68EEEDD5BFFDA0CA55978074C58" xlink:to="loc_iart_OrthopedicsandTissueTechnologiesMember_ED414F848BE59D9C0664A5597807FE6B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract" xlink:label="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_ADA02B10089FFB42FF70A55978071895" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0A0F5714D146EE510FCEA5597807743F" xlink:to="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_ADA02B10089FFB42FF70A55978071895" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_96471090A51FF847B5FDA559780773DB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_ADA02B10089FFB42FF70A55978071895" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_96471090A51FF847B5FDA559780773DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationProfitLossAbstract" xlink:label="loc_us-gaap_SegmentReportingInformationProfitLossAbstract_CFD29D3FE568EA602AEAA5597807E2A7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0A0F5714D146EE510FCEA5597807743F" xlink:to="loc_us-gaap_SegmentReportingInformationProfitLossAbstract_CFD29D3FE568EA602AEAA5597807E2A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_324451C88694767A64F3A5597807B312" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationProfitLossAbstract_CFD29D3FE568EA602AEAA5597807E2A7" xlink:to="loc_us-gaap_OperatingIncomeLoss_324451C88694767A64F3A5597807B312" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_FEAFFCD4DA336424F562A5597807A4F6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0A0F5714D146EE510FCEA5597807743F" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_FEAFFCD4DA336424F562A5597807A4F6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/SegmentAndGeographicInformationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/SegmentAndGeographicInformationTotalRevenueByMajorGeographicAreaDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1899D83EA5093FAB7264B966F0CECB83" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6F9F7CBB20E245AF4DAFB966F0CEF56B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1899D83EA5093FAB7264B966F0CECB83" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6F9F7CBB20E245AF4DAFB966F0CEF56B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_4D5C863DA0A37E063E49B966F0CEFE20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6F9F7CBB20E245AF4DAFB966F0CEF56B" xlink:to="loc_srt_StatementGeographicalAxis_4D5C863DA0A37E063E49B966F0CEFE20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_4D5C863DA0A37E063E49B966F0CEFE20" xlink:to="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_4D5C863DA0A37E063E49B966F0CEFE20" xlink:to="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_2895B54A47F6C84ED751B966F0CED24A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:to="loc_country_US_2895B54A47F6C84ED751B966F0CED24A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_EuropeMember" xlink:label="loc_srt_EuropeMember_1F2BB71C9B99705CC532B966F0CE24FC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:to="loc_srt_EuropeMember_1F2BB71C9B99705CC532B966F0CE24FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_AsiaPacificMember" xlink:label="loc_srt_AsiaPacificMember_700CD170BF1749A1D8F1B966F0CECDCB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:to="loc_srt_AsiaPacificMember_700CD170BF1749A1D8F1B966F0CECDCB" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_RestOfWorldMember" xlink:label="loc_iart_RestOfWorldMember_C6DB2DE0DE321A2CDBE1B966F0CE9156" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B9C4B2CA1C3F38C6AC79B966F0CEF8E9" xlink:to="loc_iart_RestOfWorldMember_C6DB2DE0DE321A2CDBE1B966F0CE9156" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_A0B13B8E61A302DA6740B966F0CE458A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1899D83EA5093FAB7264B966F0CECB83" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_A0B13B8E61A302DA6740B966F0CE458A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/StockBasedCompensation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/StockBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7E49A4751C0F897A0A89A55978944ADE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7E49A4751C0F897A0A89A55978944ADE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_0CA11FA3FA8E5BE6C23CA5597894A69F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7E49A4751C0F897A0A89A55978944ADE" xlink:to="loc_us-gaap_AwardTypeAxis_0CA11FA3FA8E5BE6C23CA5597894A69F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0CA11FA3FA8E5BE6C23CA5597894A69F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0CA11FA3FA8E5BE6C23CA5597894A69F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_5D49CD3F8876459A6E8CA55978947594" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:to="loc_us-gaap_EmployeeStockOptionMember_5D49CD3F8876459A6E8CA55978947594" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_PerformanceStockAndRestrictedStockAwardsMember" xlink:label="loc_iart_PerformanceStockAndRestrictedStockAwardsMember_E3F04A4BBF92D0232226A55978941793" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:to="loc_iart_PerformanceStockAndRestrictedStockAwardsMember_E3F04A4BBF92D0232226A55978941793" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_RestrictedStockAwardsAndUnitsMember" xlink:label="loc_iart_RestrictedStockAwardsAndUnitsMember_8350DF441C186A4B6545A5597894155B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:to="loc_iart_RestrictedStockAwardsAndUnitsMember_8350DF441C186A4B6545A5597894155B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:label="loc_us-gaap_PerformanceSharesMember_32BA9CA0208E2C43D394A55978944D0D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_E8876DBCB9217C54744BA55978949F9A" xlink:to="loc_us-gaap_PerformanceSharesMember_32BA9CA0208E2C43D394A55978944D0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_95160319BCA78D39F5E5A55978943D7F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7E49A4751C0F897A0A89A55978944ADE" xlink:to="loc_us-gaap_TitleOfIndividualAxis_95160319BCA78D39F5E5A55978943D7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_95160319BCA78D39F5E5A55978943D7F" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_95160319BCA78D39F5E5A55978943D7F" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DirectorMember" xlink:label="loc_us-gaap_DirectorMember_7B2A15328957CA1E8A8DA55978944A38" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D" xlink:to="loc_us-gaap_DirectorMember_7B2A15328957CA1E8A8DA55978944A38" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_EmployeeMember" xlink:label="loc_iart_EmployeeMember_2918BFAA75EA0781579DA55978941D69" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D" xlink:to="loc_iart_EmployeeMember_2918BFAA75EA0781579DA55978941D69" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_DirectorsandCertainExecutiveOfficersMember" xlink:label="loc_iart_DirectorsandCertainExecutiveOfficersMember_2BD8496618126CCBF08DA5597894E158" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_9BBFE426C2AEF630A006A55978941B5D" xlink:to="loc_iart_DirectorsandCertainExecutiveOfficersMember_2BD8496618126CCBF08DA5597894E158" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_05B9D5069487F7D54CB1A559789412A4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7E49A4751C0F897A0A89A55978944ADE" xlink:to="loc_srt_RangeAxis_05B9D5069487F7D54CB1A559789412A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_05B9D5069487F7D54CB1A559789412A4" xlink:to="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_05B9D5069487F7D54CB1A559789412A4" xlink:to="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_C6A17DA66CE6F0746815A559789470FC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE" xlink:to="loc_srt_MinimumMember_C6A17DA66CE6F0746815A559789470FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_8DE0DDC64D257E9979C6A559789418B7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_EFE93841F209036FC068A559789401EE" xlink:to="loc_srt_MaximumMember_8DE0DDC64D257E9979C6A559789418B7" xlink:type="arc" />
    <link:loc xlink:href="iart-20180630.xsd#iart_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlans" xlink:label="loc_iart_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlans_72E45CFC2223ACE98513A55978949645" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_iart_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlans_72E45CFC2223ACE98513A55978949645" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_6F3074AC8200D2A5E36FA559789486EB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_6F3074AC8200D2A5E36FA559789486EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_642403B96E597B7955D3A559789467A2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_642403B96E597B7955D3A559789467A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_818A9FAEE06E5BFC5EA5A5597894D540" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_818A9FAEE06E5BFC5EA5A5597894D540" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_E46B9DB8FD432082AA6BA5597894B4C3" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_E46B9DB8FD432082AA6BA5597894B4C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_3A597EF1729BD0BA3E1AA5597894190E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_3A597EF1729BD0BA3E1AA5597894190E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_563243B58EBFAFB69EC0A5597894DE5E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_563243B58EBFAFB69EC0A5597894DE5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_794B55CC264E5C503144A559789443DB" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C447D09621735D6FF551A5597894DD77" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_794B55CC264E5C503144A559789443DB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://integralife.com/role/TreasuryStock" xlink:type="extended" />
  <link:definitionLink xlink:role="http://integralife.com/role/TreasuryStockNarrativeDetails" xlink:type="extended" />
</link:linkbase>





