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ObjectiveToreconstructthree-dimensional(3D)finiteelementmodelsofnormalpelvisandTileB1(open-booktype)pelvicinjurywithinternalfixationmodels,andevaluatethecharacteristicofbiomechanicsbyfiniteelementanalysisrespectively.Methods Reconstructedthree-dimensionalmodelsofnormalpelvisandTileB1pelvicinjurymodelsbysoftwareMimics,GeomagicStudioandUGwithCTdataofahealthyvolunteer.Afterthat,modelswereimportedintosoftwareANSYSWorkbenchtoreconstruct3Dfiniteelementmodels.Atlast,biomechanicalstabilityandequivalentstress(vonMisesstress)distributionofinternalfixationswerecomparedandanalyzedaftermeshing,materialpropertydefinition,boundaryconstraintandexertingverticalload.Results Theeffectivenessandvalidityofnormalpelvicmodelwasproved.Themaximumvalueofequivalentstressofsingle5-holeplate model,double5-holeplatemodel,single7-holeplatemodelanddouble7-holeplatemodelwere31.779MPa,40.263MPa,35.840MPaand40.293MParespectively,allofwhichconcentratedinthecombiningsiteofscrewsandplates.Themaximumvalueofequivalentstressof7.3mmcannulatedscrewfixationmodelwas23.247MPawhichconcentratedinthemiddleofthe shaft.Themaximumvalueofequivalentstrainofpubicsymphysisofsingle5-holeplatemodel,double5-holeplatemodel,single 7-holeplatemodel,double7-holeplatemodelandcannulatedscrewwere1.4116×10-2,6.0527×10-3,1.4300×10-2,6.0056×10-3 and1.2086×10-2respectively.ConclusionAllthefivefixationsprovidedreliablestabilities.Ontheonehand,double-plate fixationsweremorestablethancannulatedscrewfixationandsingle-platefixations,however,thestress-shieldingeffectmay moreobviouslywithdouble-platefixationsandmedialscrewsweremorelikelytohavebreakageandscrewlooseningthanlateralscrews.Ontheotherhand,cannulatedscrewinternalfixationwaslesslikelytohaveimplantsbreakageandfailurethan screw-platesystem,whichhadabiomechanicaladvantage.