股骨柄假体的设计和临床应用选择

髋关节假体的设计和临床应用选择应明MD,PhD股骨柄临床成功的重要因素设计理念表面处理假体材料非骨水泥股骨柄材料钛合金(钛铝钒,钛铝铌)钴铬钼合金不锈钢非骨水泥股骨柄经典设计方型柄圆形柄锥形柄解剖柄组配柄方形柄圆形柄锥形柄解剖柄组配柄非骨水泥股骨柄植入后的稳定•柄局部与髓腔的紧密匹配和卡压初期稳定•骨长上或骨长入远期稳定非骨水泥股骨柄初期稳定的部位非骨水泥股骨柄远期稳定的实现•粗糙表面骨长上•多孔表面骨长入粗糙表面上的骨长上多孔表面上的骨长入采用多种不同的工艺，在非骨水泥柄表面形成具有一定厚度的多孔涂层，以利骨长入多孔内而获得柄远期稳定对表面多孔涂层的要求孔隙率对骨长入的影响孔隙大小对骨长入的影响孔隙大小(um)骨长入情况50结缔组织形成，无骨长入100有矿化骨组织侵入，有可能血管化200骨组织生长明显300明确加速骨组织的生长400骨组织进入孔隙深部仍有可能500骨组织生长速度受限，进入深部受限孔隙大小对术后抗剪力强度的影响各种不同多孔表面的骨接触百分比钛多孔表面植入后1个月植入后6个月钛丝21.8±2.5%43.2±4.5%钛珠34.0±4.2%33.3±2.9%等离子喷涂32.5±3.8%41.9±5.2%多孔涂层比较VPSVPSVPS原理涂层形成过程多孔表面上的骨长入非骨水泥柄的选择中的其他考虑假体选择的正确——髓腔评价型号选择的准确——术前计划并发症的预见（应力遮挡、大腿疼痛）颈干角/颈距/颈长/颈高/肢体长度股骨柄的发展195019601970198019902000骨水泥柄非骨水泥柄对非骨水泥柄热情下降骨水泥柄回潮非骨水泥柄回潮骨水泥柄的两种基本设计理念•主要关注载荷分散承载锥型•主要关注柄的形状组合柱型骨水泥柄的两种基本设计骨水泥柄的两种基本设计承载锥型组合柱型柄体材料CoCr，SSCoCr,SS,Ti合金柄体形状锥形为主截面方、椭圆颈领通常无通常有表面处理高抛光毛糙、粗糙骨水泥层的要求较低较高植入后下沉显著(0.9-1.4mm)甚小(0.1-0.5mm)骨水泥柄设计的两种思想承载锥型组合柱型骨水泥层是不可能完美的，股骨柄与骨水泥层之间的绑定也无法完美。因此通过允许柄的下沉达到二次稳定，使骨水泥在柄与骨骼之间形成良好的充填，使应力更好地从柄传递到骨水泥层再到骨骼应尽一切可能获得骨水泥层的完美，增加骨水泥层与柄之间的邦定，这是植入柄远期稳定的基础。因此应尽量限制柄的任何下沉或微动。增加颈领、表面粗糙化处理等均是出于这一目的。骨水泥柄中的“法国悖论”髓腔锉与植入柄同号尽可能植入较大号柄可去除较多的松质骨无需均匀的骨水泥层柄可直接与骨质接触A,Neck-stemangleisreduced.B,Neckisattachedatmoremedialpositiononstem.Large-diameterheadwithtrapezoidalneck(A)hasgreaterrangeofmotionandlessimpingementthansmallerdiameterheadandskirtedmodularneck(B).DefinitionPMstem.Proximallongitudinalgroovesandsurfacetexturingpromotemechanicalinterlockwithcement.Integralproximalanddistalpolymethylmethacrylatespacersensureneutralpositioningincanalandadequatethicknessofcementmantle.(CourtesyofStrykerOrthopaedics,Kalamazoo,Mich.)OmnifitEONstem(StrykerOrthopaedics,Kalamazoo,Mich).Normalizedproximaltexturingconvertsshearforcestocompressiveforces.A,Standardoffset.B,Enhancedoffset.SpectronEFstem.Rounded,rectangularshapeandlongitudinalgrooveimproverotationalstability.A,Highoffset.B,Standardoffset.(CourtesyofSmith&Nephew,Memphis,Tenn.)CPThipstem(Zimmer,Warsaw,Ind).Collarless,polished,tapereddesignallowscontrolledsubsidenceandmaintainscompressivestresseswithincementmantle.Basiccementlessstemshapes(StrykerOrthopaedics,Kalamazoo,Mich).A,MeridianTMZFstraightstemissymmetricalandfitseitherfemur.B,CitationTMZFanatomicalstemdesignincorporatesproximalposteriorbowandantevertedfemoralneck.Synergyporousstem(Smith&Nephew,Memphis,Tenn).Taperedstraightstemdesign.Proximalflutesprovideadditionalrotationalstability.A,Standardoffset.B,Highoffset.Shownwithoxidizedzirconiaheads.APRstem(Zimmer,Warsaw,Ind).Collaredanatomicaldesign.Standard(A)andlargebody(B)componentsprovidevariableproximalfitforgivendistalstemsize.Taperlocstem.Plasma-sprayedtitaniumporoussurface.Collarless,flat,wedge-shapedgeometryisavailablewithtwofemoraloffsets.(CourtesyofBiomet,Warsaw,Ind.)VerSysstem.Collaredtitaniumalloystemwithtitaniumfibermetalcircumferentialporoussurface.Trapezoidalproximalgeometryanddistalflutespromoterotationalstability.(CourtesyofZimmer,Warsaw,Ind.)S-ROMmodularstem.A,Multipleproximalsleevesizescanbecombinedwithgivendiameterstem.Stemcanberotatedinrelationtosleevetocorrectrotationaldeformityoffemur.Distalflutesimproverotationalstability.B,Long,curvedstem.Distalpartofstemisslottedincoronalplanetodiminishbendingstiffness.(CourtesyofJohnson&Johnson,DePuy,Warsaw,Ind.)Extensivelyporous-coatedstems.A,AMLstemforprimaryandrevisionarthroplastieswhenisthmusisintact.B,ExtensivelycoatedSolutionlongstemusedforrevisionswhenproximalbonelossissevere.C,Calcarreplacementlongstem.(CourtesyofJohnson&Johnson,DePuy,Warsaw,Ind.)Noncircumferentialporouscoating.Despiteexcellentingrowthintoporouspad,debrismaymigratetodistalaspectofstemthroughadjacentsmoothchannels(arrow).Alloclassicstem(Zimmer,Warsaw,Ind).Conicalstraightstemwithrectangularcrosssection.Titaniumalloywithgrit-blast,nonporoussurface.Corailstem(Johnson&Johnson,DePuy,Warsaw,Ind).Titaniumalloystemwithextensivehydroxyapatitecoating.Proximalridgesanddistalgroovesprovideadditionalstability.Specializedfemoralcomponentsforreplacementofvariablelengthofproximalfemur.OrthogenesisLimbPreservationSystem.Modularsegmentalreplacementstemforreplacementoflargesegmentofproximalfemur.Stemcanbecombinedwithtotalkneereplacementtoreplaceentirefemur.(CourtesyofJohnson&Johnson,DePuy,Warsaw,Ind.)EnduranceCDHstem.Straightsmall-diameterstemdesignisidealforuseinpatientswithdevelopmental(congenital)hipdysplasiaorsmallstature.(CourtesyofJohnson&Johnson,DePuy,Warsaw,Ind.)Acetabularcomponentdesignedforcementfixation.Texturedsurfaceandpolymethylmethacrylatespacersoptimizecementmantleandcement-prosthesisinterface.(CourtesyofSmith&Nephew,Memphis,Tenn.)Contourantiprotrusiocage(Smith&Nephew,Memphis,Tenn)hastitaniumsupportringfixedtoiliumandischiumwithscrews.Alternatively,inferiorfincanbeimpactedintoischiumwithoutscrews.Universalacetabularcomponent(Biomet,Warsaw,Ind).Titaniumplasmaspraycoatingwithdomeandrimscrewfixationoptions.Interfitacetabularcomponent.Hemisphericaldesignwithgradualtransitiontoenlargementinperipheralrimforimprovedinitialstabilityandperipheralstresstransfer.(CourtesyofSmith&Nephew,Memphis,Tenn.)Arrayoflinero