Gait adaptationsarepersistentaftertotalhiparthroplastyandcandependonthetypeofsurgery.This studyfocusedontwosurgicalapproaches:anteriorandlateral.Toanalyzegaitadaptations, biomechanicalanalysesusuallyemployan a priori selectionoftheparametersthatleadstoincomplete or redundantinformation.Incontrast,PrincipalComponentAnalysis(PCA)providesanefficient transformationofthedatasetbyautomaticallyidentifyingthemajorsourcesofvariability.Thepurpose of thisstudywastoinvestigatedifferencesinlevel-walkingamongthreegroupsofparticipantsusing PCA:patientsundergoingananteriorsurgicalapproach,patientsundergoingalateralsurgical approach,andhealthycontrols.Biomechanicaldescriptionsoftheextractedprincipalcomponents aidedintheinterpretationofthestatisticallysignificantresultsobtainedfrommultivariateanalysisof covariance(MANCOVA)tests.Apointsystemwasintroducedtosummarizetheresultsandguidethe interpretation.PCAcapturedreducedmagnitudeinsagittalandfrontalmomentsintheanterior approachgroup,andreducedsagittalpeaksangleinthelateralgroup,aspreviouslyfoundwith traditionalanalyses.PCAalsoidentifiedsignificantpatterndelaysintheanteriorgroup,unnoticedin previousstudies.Inconclusion,neithersurgicalapproachrestorednormalgaitfunctionalitybecause lower extremitykineticsandkinematicsalterationspersistedat300-dayfollow-upafterthesurgery, regardlessofthetechnique.