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现代全踝关节置换的历史、发展、进展、未来方向，包括假体设计、适用证、手术方法、临床效果、并发症_现代全踝关节置换的评价:叙述性回顾（2024）Anevaluationofthetotalanklereplacementinthemodernera:anarrativereview ShaffreyI,HenryJ,DemetracopoulosC.Anevaluationofthetotalanklereplacementinthemodernera:anarrativereview[J].AnnTranslMed,2024,12(4):71.转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/39118953/转载文章的原链接2：https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11304414/ AbstractBackgroundandObjectiveTotalanklereplacementhasbecomeanincreasinglypopularsurgicalprocedurefortreatmentofend-stageanklearthritis.Thoughanklearthrodesishashistoricallybeenconsideredthegoldstandardtreatment,advancementsinimplantdesign,functionaloutcomes,andsurvivorshiphavemadetotalanklereplacementacompellingalternative.Particularly,inthepast20years,totalanklereplacementhasundergonetremendousinnovation,andthefieldofresearchinthisprocedurecontinuestogrow.Inthisreview,weaimtosummarizethehistory,evolution,advancements,andfuturedirectionsoftotalanklereplacementasdescribedthroughimplantdesign,indications,surgicalprocedures,complications,andoutcomes.全踝关节置换术已成为治疗终末期踝关节关节炎的一种日益流行的手术方法。虽然踝关节融合术历来被认为是金标准的治疗方法，但随着植入物设计、功能结果和生存率的提高，全踝关节置换术已成为一种令人信服的选择。特别是在过去的20年里，全踝关节置换术经历了巨大的创新，该手术的研究领域也在不断发展。在这篇综述中，我们旨在总结全踝关节置换术的历史、发展、进展和未来方向，包括植入物设计、适应症、手术方法、并发症和结果。 MethodsLiteraturesearcheswereconductedinPubMedtoidentifyrelevantarticlespublishedpriortoMarch2023usingthefollowingkeywords:“totalanklereplacement”,“totalanklearthroplasty”,and“totalankle”.在PubMed中检索2023年3月之前发表的相关文章，检索关键词为:“全踝关节置换”、“全踝关节置换”和“全踝”。 KeyContentandFindingsTotalanklereplacementhasdemonstratedsignificantimprovementsinsurgicaltechnique,implantdesign,survivorship,andclinicalandfunctionaloutcomesinthemodernera.Theprocedurereportshighpatientsatisfaction,lowcomplicationrates,andimprovedfunctionalabilitiesthatchallengethecurrentgoldstandardtreatmentforanklearthritis.在现代，全踝关节置换术在手术技术、植入物设计、存活、临床和功能结果方面都有显著的改进。该手术报告患者满意度高，并发症发生率低，并改善了功能，挑战了目前治疗踝关节关节炎的黄金标准。 ConclusionsThoughthereareareasofimprovementfortotalanklereplacement,theproceduredemonstratespromisingoutcomesforpatientswithend-stageanklearthritistoimprovepainandfunctionalabilities.Researchstudiescontinuetoexplorevariousthefacetsoftotalanklereplacement,includingoutcomes,riskfactors,noveltechniquesandmodalities,andcomplications,todirectfutureinnovationandtooptimizepatientresults.虽然全踝关节置换术有改进的地方，但该手术对终末期踝关节关节炎患者改善疼痛和功能能力的效果很有希望。研究继续探索全踝关节置换术的各个方面，包括结果、风险因素、新技术和模式以及并发症，以指导未来的创新并优化患者的结果。 Keywords:Totalanklereplacement(TAR),totalanklearthroplasty(TAA),anklearthritis IntroductionTotalanklereplacement(TAR)hasundergonetremendousdevelopmentssinceitsinception50yearsago.Inthemodernera,therehasbeenimmensegrowthinannualvolumes,increasingby564%between2005to2017(1),asindicationsforsurgeryexpand,surgicaltechniquesrefine,andoutcomesimprove.Concurrently,theliteraturesurroundinganklereplacementcontinuestoevolveasnewinsightsanddiscoveriesarepublished.Atthistime,thefieldofTARhasintroduceditsfourthgenerationofimplants,increaseditssurgicalindications,improveditsimplantsurvivorship,minimizeditscomplications,anddevelopednewtechnologyaimedtooptimizepatientoutcomes.全踝置换术(TAR)自50年前问世以来，经历了巨大的发展。在现代，随着手术适应症的扩大、手术技术的改进和结果的改善，年交易量有了巨大的增长，2005年至2017年增长了564%(1)。同时，随着新的见解和发现的发表，关于踝关节置换术的文献也在不断发展。此时，TAR领域已经推出了第四代植入物，增加了手术指征，提高了植入物的存活率，最大限度地减少了并发症，并开发了旨在优化患者预后的新技术。ThisreviewaimstosummarizethecurrentknowledgeofTARasdescribedthroughitsevolution,improvements,andfuturedirections.WepresentthisarticleinaccordancewiththeNarrativeReviewreportingchecklist.这篇综述的目的是通过TAR的演变、改进和未来方向来总结目前对其的了解。我们按照叙述性评论报告清单来呈现这篇文章。 MethodsWereviewedtheresultsofclinicalstudiesandmeta-analysesofTARspresentedonPubMed.Thesearticlesincludedtopicsaboutthehistory,indications,surgicaltechnique,complications,outcomes,andfutureofTARs,aswellascomparativestudiesbetweenTARsandanklearthrodesis.Thesearticleswereidentifiedusingthefollowingkeywords:“totalanklereplacement”,“totalanklearthroplasty”,and“totalankle”(Table1).  Table1ThesearchstrategysummaryItems        SpecificationDateofsearch  March1,2023DatabasesandothersourcessearchedPubMedSearchtermsused     Totalanklereplacement,totalanklearthroplasty,andtotalankleTimeframe       EnglishabstractsandarticlesbeforeMarch2023Inclusioncriteria       EnglishabstractsandarticlesSelectionprocess      LiteraturesearchwasconductedbyI.S.Finalapprovalofliteraturesearchwasconductedbyallauthors  DiscussionHistoryPriortotheintroductionofanklereplacements,theonlyoperativetreatmentoptionforend-stageanklearthritiswasanklearthrodesis,consideredthe‘gold-standard’treatment.Thoughtheresultsofanklearthrodesiswereshowntoachievegoodclinicaloutcomesandhighsatisfactionscores,concernsaboutcomplicationsandfunctionaloutcomesstillexisted(2,3).Namely,anklearthrodesishadcomplicationswithnonunion,malunion,andinfectionfollowingsurgery,withlimitedsalvageoptions(4).Furthermore,patientswithanklearthrodesisexperienceddecreasedsagittalplanemotioninthehindfoot,slower,asymmetricalgait,andultimately,degenerativearthritischangesinadjacentjoints(5-7).Theseshortcomingsinanklearthrodesispromptedexplorationinalternativetreatmentoptions,includingjointreplacement.在引入踝关节置换术之前，终末期踝关节关节炎的唯一手术治疗选择是踝关节融合术，被认为是“金标准”治疗。尽管踝关节融合术的临床效果良好，满意度较高，但对并发症和功能结局的担忧仍然存在(2,3)。也就是说，踝关节融合术有术后不愈合、不愈合和感染等并发症，且挽救选择有限(4)。此外，踝关节融合术患者后足矢状面运动减少，步态变慢、不对称，最终相邻关节发生退行性关节炎变化(5-7)。踝关节融合术的这些缺点促使人们探索包括关节置换术在内的替代治疗方案。 FirstgenerationThefirstgenerationofTARimplants,developedinthe1970s,featuredavarietyofdesignsthatattemptedtomimicthesuccessfulfeaturesofhipandkneearthroplasty.Thoughtherewaswidevariabilityinprosthesisdesigns,thebasicmodelofthisgenerationfeaturedatwo-partsystemwithapolyethyleneconcavearticularcomponentandaconvexcobaltchromemetalcomponent.Thisgenerationhadbothconstrainedandunconstrainedsystems,eachwiththeirownramificationscontributingtohighfailureratesandunsatisfactoryoutcomes.Constrainedsystemslimitedthedissipationofstressesbetweenthecontactsurfaces,contributingtohighratesofloosening;unconstrainedsystemsplacedincreasedstressesonthesurroundingligamentsoftheankle,leadingtoproblemsofmalalignment(8,9).Moreover,thisearlygenerationofimplantsusedcementedfixationandrequiredextensiveboneresectiontoproperlypositionthecomponent.Thisfirstgenerationofimplantsencounteredseveralissues:highratesofloosening(between29–90%at10years),lowsatisfactionscores,andpoorsurvivorship(8-11).Thepoorresultsassociatedwiththeimplantsofthisgenerationledtothecompleteabandonmentofthesedesigns.Nonetheless,thisgenerationofferedimmenseinsightforimprovementsinthefuturegenerationsofimplants,includingconsiderationsaboutminimizingbonyresection,balancingsofttissue,anddecreasingshearstressforces(10,12).20世纪70年代开发的第一代TAR植入物具有多种设计，试图模仿髋关节和膝关节置换术的成功特征。虽然假体设计有很大的可变性，但这一代的基本模型具有两部分系统，其中包括聚乙烯凹关节组件和凸钴铬金属组件。这一代既有受约束的系统，也有不受约束的系统，每个系统都有自己的分支，导致高失败率和令人不满意的结果。约束系统限制了接触面之间应力的消散，导致高松动率;无约束系统增加了踝关节周围韧带的压力，导致了错位问题(8,9)。此外，早期的植入物使用骨水泥固定，需要广泛的骨切除来正确定位组件。第一代植入物遇到了几个问题:高松动率(10年在29-90%之间)、低满意度评分和低生存率(8-11)。与这一代植入物相关的不良结果导致了这些设计的完全放弃。尽管如此，这一代为未来几代植入物的改进提供了巨大的见解，包括考虑最小化骨切除，平衡软组织和减少剪切应力(10,12)。 SecondgenerationThesecondgenerationofTARwasintroducedtothemarketinthemid-1980s,incorporatingnovelimplantfeaturesthatattemptedtoaddresstheshortcomingsofthepreviousgeneration.Pooroutcomesattributedtocementedfixationandlargeboneresectioninthefirstgenerationledtoatransitiontowardscementlessimplantsinthesecondgeneration.Inaddition,thesedesignsfeaturedporous-coatedmetallictibialimplantsintendedtostimulateosseousintegrationanddecreasehighratesofloosening.第二代TAR于20世纪80年代中期引入市场，结合了新颖的植入物特征，试图解决上一代的缺点。第一代骨水泥固定和大骨切除的不良结果导致第二代骨水泥植入物的过渡。此外，这些设计的特点是多孔涂层金属胫骨植入物旨在刺激骨整合和降低高松动率。Inthepreviousgeneration,bothhighlyconstrainedandhighlyunconstraineddesignswereassociatedwithalitanyofcomplications.Learningfromthisinsight,thesecondgenerationofTARdevelopedtwocategoriesofimplants,fixed-bearingandmobile-bearing,thathopedtomitigatepreviousshortcomings.Fixed-bearingimplantsconsistofatibial,talar,andfixedpolyethylenecomponent,thatfunctionasatwo-componentimplant.Incontrast,mobile-bearingimplantsfeaturethesamethreecomponents(tibia,talus,andpolyethylene),butimplementanunconstrainedpolyethyleneinsertthatcanarticulatebetweenthetibialandtalarcomponents(11,13,14).Fixed-bearingimplantshavehigherconstraintthanmobile-bearing,whichallowsforgreaterstability,butalsoincreasestheriskofimplantloosening.Thoughmobile-bearingimplantshaveminimalconstraintacrossthepolyethyleneinserttodecreaseloadstress,therearestillconcernsaboutpolyethylenewear,instability,andtranslation.Outcomeswerestilllargelyvariableinthesecond-generationdesigns.Inonemeta-analysisof1,105secondgenerationTARs,theaveragesurvivorshipacross7implantswas90%at5years,thoughsurvivorshiprangedbetween68%to100%acrossdifferentstudies(13).Further,thisgenerationcitedresidualissueswithimplantsubsidence,residualpain,andlimitedrangeofmotion(13).在上一代，高度约束和高度不约束的设计都伴随着一连串的复杂问题。从这一见解中学习，第二代TAR开发了两类植入物，固定轴承和移动轴承，希望减轻以前的缺点。固定轴承植入物包括胫骨、距骨和固定聚乙烯组件，其功能为双组件植入物。相比之下，移动轴承植入物具有相同的三个组件(胫骨、距骨和聚乙烯)，但实现了可以在胫骨和距骨组件之间铰接的不受约束的聚乙烯插入物(11,13,14)。固定轴承植入物比移动轴承具有更高的约束，允许更大的稳定性，但也增加了植入物松动的风险。虽然移动轴承植入物在聚乙烯插入物上具有最小的约束以降低载荷应力，但仍然存在聚乙烯磨损、不稳定和易动的问题。在第二代设计中，结果仍然很大程度上是可变的。在一项对1105例第二代TARs的荟萃分析中，7种植入物的5年平均生存率为90%，尽管不同研究的生存率在68%至100%之间(13)。此外，这一代人还提到了植入物下沉、疼痛和活动范围受限等遗留问题(13)。 Moderngenerations(thirdandfourth)AfterthefirsttwogenerationsofTAR,modernimplantswererefinedtominimizebonyresectionandrespectlocalanatomy.Moreover,surgeonshadgreaterappreciationformechanicalalignmentandbalancingtheanklewithadditionalbonyandsofttissueprocedurestoensureastableankleandfootaroundthereplacement.Modernimplantsincludebothfixed-bearing,two-componentdesignsandmobile-bearing,three-componentdesigns;althoughtheformerismorecommonintheUnitedStates,thelatterinEurope.Acknowledgingthepatternoffailureassociatedwithcementedimplantation,third-generationimplantsfeaturedcementlessdesigns,utilizingtitaniumplasma-spraycoatingsforboneingrowth(15).Popularthird-generationimplantsincludetheINBONE(WrightMedical,Memphis,TN,USA),SaltoTalaris(IntegraLifesciences,Princeton,NJ,USA),STAR(Stryker,Kalamazoo,MI,USA),andHINTEGRA(IntegraLifeSciences,Newdeal,Lyon,France)andhavebeenassociatedwithgoodsurvivorshipandhighsatisfactionscores.在前两代TAR之后，现代植入物经过改进，以尽量减少骨切除并尊重局部解剖。此外，外科医生对机械对齐和平衡踝关节有了更大的认识，并通过额外的骨和软组织手术来确保踝关节和足部在置换物周围的稳定。现代种植体包括固定轴承，双组件设计和移动轴承，三组件设计;尽管前者在美国更常见，后者在欧洲更常见。认识到骨水泥植入失败的模式，第三代种植体采用无骨水泥设计，利用钛等离子喷涂涂层进行骨长入(15)。流行的第三代植入物包括INBONE(WrightMedical,Memphis,TN,USA)、SaltoTalaris(Integralifessciences,Princeton,NJ,USA)、STAR(Stryker,Kalamazoo,MI,USA)和HINTEGRA(IntegraLifeSciences,Newdeal,Lyon,France)，这些植入物具有良好的生存率和高满意度。TheINBONEtotalankleimplant,originallycreatedin2005,featuresauniquemodularstemtibialdesignandintermedullarystemalignmentguidewiththeintentiontomaximizebonyfixation(16).TheoriginalINBONEprosthesis(INBONEI)employedaflat-cut,saddletalarcomponentthatsimilarlyfeaturedarobusttalarstem;however,afterreportsoftalar-sidedfailures,thetalarcomponentwasrevisedinitsseconditeration(INBONEII)(16).Usinganexternaljigtosecurethelegandfluoroscopytoachieveproperalignment,thetibialcomponentisimplantedviaintramedullaryreamingthroughthecalcaneusandtalus.TheINBONETARcanbeusedinbothprimaryandrevisionsettings,performingasaviablealternativeincasesoffailedTARwithlooseningandboneloss.Moreover,addedstabilityfromtherobusttibialstemallowstheINBONEimplanttobeareasonableoptionforpatientswithseveredeformityorinstability(15).INBONE全踝植入物最初创建于2005年，具有独特的模块化胫骨干设计和髓间干对齐引导，旨在最大限度地实现骨固定(16)。原始的INBONE假体(INBONEI)采用平切鞍状距骨组件，同样具有坚固的距骨柄;然而，在报道距侧失败后，距侧组件在第二次迭代(INBONEII)中进行了修订(16)。使用一个外部夹具来固定腿部，并在透视下达到正确的对齐，胫骨假体通过髓内扩孔通过跟骨和距骨植入。INBONETAR可用于初级和翻修设置，在TAR失败导致松动和骨质流失的情况下，作为可行的替代方案。此外，强健的胫骨干增加的稳定性使得INBONE植入物成为严重畸形或不稳定患者的合理选择(15)。SurgicaloutcomesoftheINBONEITARreportsurvivorshipof89%atonly3.7yearsoffollow-up,withhighincidenceoftalarsubsidence(17).FurtherstudieshaveidentifiedtheINBONEIasanindependentriskfactorforfailure,againcitingtalarsubsidenceastheprimaryreasonforrevision(18).Therehasbeensomeevidencetosuggestthehighincidenceoftalarsubsidenceisaresultoftalarosteonecrosisinstigatedbytheintraoperativeintermedullaryreaming,thoughnodefinitivecausehasbeenelucidated(19).In2010,arevisedversionoftheimplant(INBONEII)wasintroduced,whichimplementedasulcus-shapedprofileandtwoanteriorpegstothetalarcomponent.MidtermoutcomesoftheINBONEIIreportsurvivorshipof98%anddecreasedincidenceoftalarsubsidence(20).INBONEITAR的手术结果显示，在仅3.7年的随访中，患者的存活率为89%，距骨下沉的发生率很高(17)。进一步的研究已经确定INBONEI是一个独立的失败风险因素，再次将地表沉降作为修订的主要原因(18)。有证据表明，距骨下沉的高发生率是术中髓间扩孔引起的距骨坏死的结果，尽管没有明确的原因被阐明(19)。2010年，引入了一种改良版的植入物(INBONEII)，它实现了一个沟状轮廓和两个前距假体。INBONEII的中期结果报告了98%的生存率，并降低了距骨下沉的发生率(20)。TheSaltoTalarisfixed-bearingTARwasfirstintroducedtotheUnitedStatesmarketin2006.However,thiswasanadaptationtoitsmobile-bearingpredecessor,theSaltoTotalAnkle,thathadbeenusedinEuropesince1997.Theimplantfeaturesacentralkeelintibiaandconical-shapedfacetinthetalarcomponent,designedtooptimizenaturalalignmentofthepatient’srotationalaxis(15).ClinicaloutcomesoftheSaltoTalarisatmidtermfollow-upciteexcellentsurvivorshipandimprovementsinpain,thoughdurabilityoftheimplantatthe10-yearmilestoneremainsundetermined(21-23).SaltoTalaris固定轴承TAR于2006年首次引入美国市场。然而，这是对其移动轴承的前身Salto全踝的改进，后者自1997年以来一直在欧洲使用。该植入物的特点是胫骨中央龙骨和距骨部分的锥形关节面，旨在优化患者旋转轴的自然对齐(15)。中期随访的临床结果显示，SaltoTalaris的生存期很好，疼痛得到了改善，但植入物在10年的耐久性仍不确定(21-23)。ThefirstiterationoftheSTARimplantwasinitiallyintroducedin1978,andfivedifferentversionsoftheSTARhavebeenusedforimplantationsince1981.Themostrecentiterationisthe4th-generationSTAR,whichwasapprovedintheUnitedStatesin2009(15).Theimplantfeaturesathree-component,mobile-bearingdesign,withatibialcomponentwithtwocylindricalbarsforfixationandasymmetrical,cylindricaltalarcomponent(15).Thedistalsideofthetibialcomponenthasasmooth,flatsurfacethatenablesunconstrainedmotionforthepolyethyleneinsert.TheversionoftheSTARusedintheUnitedStatespossessesatitaniumplasmaspraytostimulateboneongrowth,distinctfromitsEuropeancounterparts(15).Long-termoutcomesoftheSTARintheUnitedStateshavereportedsurvivorshipratesbetween90%to95%at10years,whichdecreasedto73%at15years(24-26).STAR植入物的第一次迭代最初于1978年推出，自1981年以来，已有五个不同版本的STAR用于植入。最新的版本是第四代STAR，于2009年在美国获得批准(15)。该植入物具有三组件，可移动承载设计，胫骨组件具有两个圆柱形棒用于固定，对称圆柱形距骨组件(15)。胫骨假体的远端具有光滑、平坦的表面，使聚乙烯插入物能够不受约束地运动。与欧洲同类产品不同，美国使用的STAR拥有钛等离子体喷雾来刺激骨骼生长。在美国，STAR的长期预后报道10年生存率为90%-95%，15年生存率为73%(24-26)。TheHINTEGRATotalAnklesimilarlywasathree-componentmobile-bearingimplantprominentlyusedinEurope,Canada,andBrazilfollowingitsapprovalintheearly2000s.Thetibialcomponentfeaturesaflatsurfacewithananteriorshieldthathastwoholesforscrewfixationinthetibia.Thetalarcomponenthasaconicalprofileandemploysananteriorshieldwithholesforscrewfixationaswell.Severallong-termlargecohortstudiesassessingsurvivorshipoftheHINTEGRAprosthesishavebeenpublishedreportingvaryingsurvivorshiprangingbetween68%to84%at10yearspostoperatively(27,28).HINTEGRA全踝是一种类似的三组件移动轴承植入物，在21世纪初获得批准后，在欧洲、加拿大和巴西得到了广泛应用。胫骨组件具有平坦的表面，其前屏蔽层具有两个孔，用于胫骨螺钉固定。距骨组件具有圆锥形轮廓，并采用具有螺钉固定孔的前护罩。一些评估HINTEGRA假体生存率的长期大型队列研究已经发表，报告术后10年生存率在68%至84%之间(27,28)。TheZimmerTrabecularMetalTotalAnkle(Warsaw,IN,USA)wasanotableintroductiontothethirdgenerationofTARimplants.Contrarytootherimplants,whichuseananteriorsurgicalapproachtotheanklejoint,theTrabecularMetalTARemploysalateraltransfibularapproach,whichrequiresfibularosteotomyandanteriortalofibularligamentresectiontoaccessthejoint.Therationalebehindthistechniquewastoallowbetterreplicationofthenaturalcurvatureofthetibiaandtalusandminimizeboneresection.Additionally,itwastheorizedthatthisapproachwoulddecreaseincidenceofwoundhealingcomplications(15).MidtermoutcomesoftheTrabecularMetalTARhavereportedgoodimplantsurvivorshipandimprovedfunctionalscoresat5years(29,30).However,inonesmallcaseseriesof16lateralapproachTARpatients,therewasa25%incidenceofcomplicationsassociatedwiththefibularosteotomy(31).Thoughthisimplanthasdemonstratedgoodsurvivorshipandpatient-reportedoutcomes,theincreasedriskoffibularnonunion,aswellasthechallengesforrevisionoftheimplant,remainaconcern(30).Zimmer金属小梁全踝(Warsaw,IN,USA)是第三代TAR植入物的重要介绍。与其他采用前路手术入路进入踝关节的植入物不同，金属小梁TAR采用外侧经腓骨入路，需要腓骨截骨和前距腓骨韧带切除术才能进入关节。这项技术背后的原理是允许更好地复制胫骨和距骨的自然弯曲，并尽量减少骨切除。此外，理论上认为这种方法可以减少伤口愈合并发症的发生率(15)。金属小梁TAR的中期结果报告了良好的种植体存活和5年功能评分的改善(29,30)。然而，在16例外侧入路TAR患者的小病例系列中，腓骨截骨术相关并发症的发生率为25%(31)。尽管该植入物表现出良好的成活率和患者报告的结果，但腓骨不连的风险增加以及对植入物翻修的挑战仍然令人担忧(30)。ThefourthgenerationofTARimplantscontinuestoimproveuponthestrengthsofthethirdgenerationtooptimizeboneintegration,mechanicalalignment,andsurgicaltechnique.IntheUnitedStates,modernfourth-generationimplantsincludeINFINITY(Stryker),Cadence(IntegraLifeSciences,Princeton,NJ,USA),Vantage(Exactech,Gainesville,FL,USA),Axiom(Kinos,Wayne,PA,USA),Apex(Paragon28,Englewood,CO,USA),Quantum(In2Bones,Memphis,TN,USA).Thesedesignsfeaturelow-profiletibialandtalarcomponentswhichminimizeboneresectionwhilestillmaintainingrobustsurfacecontact(15).Giventheirrelativenoveltyoftheseimplants,thelong-termoutcomesareuncertain;however,earlyreportsdemonstrategoodsurvivorshiprangingbetween92%to98%,andsignificantimprovementsinfunctionalandpainscorespostoperativelyinthefirsttwoyears(32-34).Long-termfollow-upandstudieswillbecriticalintheevaluationofimplantsurvivorshipaftertheearlyandmid-termperiods.第四代TAR植入物在第三代的基础上继续改进，以优化骨整合、机械对准和手术技术。在美国，现代第四代植入物包括INFINITY(Stryker)、Cadence(IntegraLifeSciences,Princeton,NJ,USA)、Vantage(Exactech,Gainesville,FL,USA)、Axiom(Kinos,Wayne,PA,USA)、Apex(Paragon28,Englewood,CO,USA)、Quantum(In2Bones,Memphis,TN,USA)。这些设计具有低轮廓的胫骨和距骨组件，可最大限度地减少骨切除，同时仍保持坚固的表面接触(15)。考虑到这些植入物相对新颖，长期结果尚不确定;然而，早期的报告显示，生存率在92%至98%之间，术后头两年功能和疼痛评分有显著改善(32-34)。长期随访和研究将是评估早期和中期种植体存活的关键。AdditionalinnovationinthefieldofTARhasledtothedevelopmentofrevisionankleimplants.Inthepast,treatmentoptionsforTARimplantfailurewerelimitedtoarthrodesisorbelow-kneeamputation(9,11,35).Inthemodernera,theINBONEimplanthascommonlybeenusedintherevisionTARsetting(36),butthereissignificantroomforimprovementinthetreatmentoffailedTAR.Currently,theonlyavailablerevisionsystemsonthemarketaretheINVISION(Stryker)andSaltoTalarisXT(IntegraLifeSciences),whicharedesignedforsettingsoflargeboneresectionandaugmentedinstability.ReportsonrevisionTARsystemoutcomesarelargelylimitedandrequirefurtherinvestigation.ItisexpectedthatnovelrevisionsystemswillcontinuetoenterthemarketasmorecompaniesinvestinthisfuturedirectionofTAR.TAR领域的其他创新导致了踝关节修复植入物的发展。过去，TAR假体失败的治疗选择仅限于关节融合术或膝下截肢(9,11,35)。在现代，INBONE种植体已被普遍用于翻修TAR设置(36)，但在治疗失败的TAR方面仍有很大的改进空间。目前，市场上唯一可用的修正系统是INVISION(Stryker)和SaltoTalarisXT(IntegraLifeSciences)，它们是为大骨切除和增强不稳定性而设计的。关于修订TAR系统结果的报告在很大程度上是有限的，需要进一步调查。随着越来越多的公司投资于TAR的未来方向，预计新的修订系统将继续进入市场。 IndicationsTheprimaryindicationforTARisend-stageanklearthritis,whichisidentifiedthroughclinicalandradiographicassessment.AsthefrequencyofTARsperformedeachyearincrease,understandingofetiologyofarthritisandassociatedoutcomesremainsapertinentareaofresearch.Post-traumaticarthritisisthemostcommonetiologyofanklearthritis,accountingforbetween70–90%ofallincidencesofend-stageankleosteoarthritis(20,23,34,37);however,traumamayrangefromintra-articularankleortalusfracturetoextra-articularfracture,chondralinjury,orchronicligamentousinsufficiencyandinstability.Otheretiologiesofanklearthritisincludeprimaryosteoarthritis,inflammatoryarthritis,andarthritissecondarytoclubfootdeformity,avascularnecrosis(AVN),orhemochromatosis.TAR的主要适应症是终末期踝关节炎，可通过临床和影像学评估确定。随着每年进行TARs的频率增加，对关节炎的病因和相关结果的了解仍然是一个相关的研究领域。创伤后关节炎是踝关节最常见的病因，占所有终末期踝关节骨关节炎发病率的70-90%(20,23,34,37);然而，创伤的范围可能从关节内踝关节或距骨骨折到关节外骨折、软骨损伤或慢性韧带功能不全和不稳定。踝关节关节炎的其他病因包括原发性骨关节炎、炎性关节炎和继发于内翻足畸形、缺血性坏死(AVN)或血色素沉着症的关节炎。Historically,theidealTARcandidatewasanolderpatientwithlowfunctionaldemands,minimaldeformityattheankleorfoot,andminimaladjacentjointarthrosis.Thesecharacteristicshavebeenassociatedwithgreaterpainresolution,diminishedcomplicationrisks,andlowerrisksoffailure.However,improvementsinsurgeonexperience,technique,andimplantdesignshavecontributedexcellentoutcomesinpatientdemographicsbeyond“ideal”criteria.从历史上看，理想的TAR候选者是年龄较大、功能需求低、踝关节或足部畸形最小、邻关节关节病最小的患者。这些特征与更大的疼痛缓解、更低的并发症风险和更低的失败风险有关。然而，外科医生经验、技术和植入物设计的改进使患者人口统计学的结果优于“理想”标准。AgeandphysicaldemandareconsideredtohavesignificantinfluenceuponTARoutcomes.Inparticular,youngerandmorephysicallyactivepatientshavebeenthoughttohaveanincreasedriskoffailureinTAR,asaresultoftheincreasedimplantlifespanandactivitydemand.However,somereportsexplicitlyinvestigatingoutcomesofTARbyagegroupshavefoundnosignificantdifferencesinrisk(38,39),whileothersciteageasanindependentpredictoroffailure(35,40).Despiteconflictingevidence,youngerpatientsstillreportexcellentfunctionalandclinicaloutcomesthatwarrantseligibilityforTAR(39,41,42).Inparticular,thepreservationofmotionfromTARisespeciallybeneficialforyoungerpatients,asitcanhelptodiminishfutureonsetandseverityofadjacentjointarthritisinthemidfootandhindfoot.Ingeneral,patientageandactivitylevelshouldbeconsideredinpre-surgicalconsultation,andsurgeonsshouldtakethesefactorsintoaccounttoguidedecision-makingandtomanagepatients’expectationsofoutcome.年龄和体力需求被认为对第三次评估报告的结果有重大影响。特别是，由于植入物寿命和活动需求的增加，年轻和更活跃的患者被认为有更高的TAR失败风险。然而，一些明确按年龄组调查TAR结果的报告发现风险没有显著差异(38,39)，而另一些报告则认为年龄是失败的独立预测因子(35,40)。尽管有相互矛盾的证据，年轻患者仍然报告了良好的功能和临床结果，保证了TAR的资格(39,41,42)。特别是，TAR对年轻患者尤其有益，因为它可以帮助减少未来中足和后足相邻关节关节炎的发病和严重程度。一般来说，术前会诊应考虑患者的年龄和活动水平，外科医生应考虑这些因素来指导决策和管理患者对结果的期望。PreoperativecoronalplanedeformityhasbeencitedasarelativecontraindicationforTARhistorically.However,morerecentstudiesdemonstratethatseverepreoperativedeformitydoesnotresultinincreasedfailure,aslongasthedeformityisabletobecorrectedintraoperatively(43).CurrentanalysisofTARoutcomesinthesettingofvarus,valgus,andneutralpreoperativealignmenthasreportedsimilarpainandfunctionalscoresandsimilarratesofcomplications,reoperation,andsurvivorshipacrossthethreegroups(44).Thoughpreoperativecoronaldeformityexceeding20°oncewasconsideredanabsolutecontraindicationforTAR,advancementsinsurgicaltechniqueandimplantdesignhavehelpedachievesatisfactoryoutcomesforcasesofseverecoronalplanedeformity(20°to35°ofvarusorvalgus)(45).Importantly,ensuringgoodoutcomesincasesoffootandankledeformityisdependentupontheuseofconcomitantprocedurestobalancetheankle.术前冠状面畸形历来被认为是TAR的相对禁忌症。然而，最近的研究表明，只要畸形能够在术中矫正，术前严重畸形并不会导致手术失败的增加(43)。目前对内翻、外翻和中性术前对准的TAR结果分析显示，三组患者的疼痛和功能评分相似，并发症、再手术率和生存率相似(44)。虽然术前冠状面畸形超过20°一度被认为是TAR的绝对禁忌症，但手术技术和植入物设计的进步已经帮助严重冠状面畸形(20°至35°内翻或外翻)的病例获得了令人满意的结果(45)。重要的是，在足部和踝关节畸形的情况下，确保良好的结果取决于使用伴随手术来平衡踝关节。ObesityhasalsobeencitedasarelativecontraindicationforTARinthepast,butthesepatientssimilarlyhaveachievedsignificantimprovementsinoutcomesinmorerecentliterature(46,47).Incurrentliterature,theevidenceassessingriskofcomplicationsandfailuresinobesepatientsisconflicting.Whileonereportcitedanincreasedfailureriskinobesepatients(48),otherstudieshavefoundminimaldifferencesinincidencesofcomplications,infection,orfailure(46,47,49).Inspiteofconflictingevidence,thereisaconsensusthatobesepatientscanachievesignificantimprovementsinpainandfunctionaloutcomesfollowingTAR,thoughtheymayhavelowerfunctionalscorescomparedtotheirnon-obesecounterparts.肥胖在过去也被认为是TAR的相对禁忌症，但在最近的文献中，这些患者同样取得了显著的改善(46,47)。在目前的文献中，评估肥胖患者并发症和失败风险的证据是相互矛盾的。虽然一份报告指出肥胖患者衰竭风险增加(48)，但其他研究发现并发症、感染或衰竭的发生率差异很小(46,47,49)。尽管有相互矛盾的证据，但有一个共识，即肥胖患者在TAR后可以显著改善疼痛和功能结果，尽管与非肥胖患者相比，他们的功能评分可能较低。DiabetespersistsasarelativecontraindicationtoTAR,especiallyinthesettingofuncontrolleddiabetes(A1C>7.0%)(50).Thoughdiabeticpatientscanstillachieveimprovementsinpainandfunctionaloutcomes,thereissignificantevidencedemonstratinganincreasedriskofcomplicationsanddelayedwoundhealingfordiabeticTARpatients(50-52).糖尿病仍然是TAR的相对禁忌症，特别是在糖尿病未控制的情况下(A1C>7.0%)(50)。虽然糖尿病患者在疼痛和功能预后方面仍然可以得到改善，但有重要证据表明糖尿病TAR患者出现并发症和伤口愈合延迟的风险增加(50-52)。AbsolutecontraindicationsforTARincludeactiveinfection,excessivelossofbonestock,neuropathicorCharcotarthropathy,inadequatesofttissueenvelopearoundtheankle,confirmedmetalallergy,andvasculardeficiencyofthelimb.Inaddition,surgeonsshouldusediscretioninpatientselectionforTARbeyondtheseabsolutecharacteristicsanddeveloptheiroperativeplanbasedontheirpatient’scharacteristics,relativerisks,andfunctionaldemands.Surgeonsmayusemagneticresonanceimaging(MRI),computedtomography(CT),orweightbearingCT(WBCT)tobettercharacterizebonequality,deformity,presenceofperiarticularcysts,andassociatedsofttissuepathologytofinalizetheirsurgicalplan(53).TAR的绝对禁忌症包括活动性感染、骨质过度流失、神经性或沙氏关节病、踝关节周围软组织包膜不足、确诊的金属过敏和肢体血管缺乏。此外，除了这些绝对特征外，外科医生在选择TAR患者时应酌情决定，并根据患者的特征、相对风险和功能需求制定手术计划。外科医生可以使用磁共振成像(MRI)、计算机断层扫描(CT)或负重CT(WBCT)来更好地表征骨质量、畸形、关节周围囊肿的存在以及相关的软组织病理，从而确定他们的手术计划(53)。 TechniquesAnanteriorapproachisthemostusedapproachformajorityofTARimplants;thereisoneimplantthatemploysalateralapproachforitsdesign,andaposteriorapproachforTARhasbeendescribedinliterature(54).Amidlineincisioncenteredovertheanklejointandtheintervalbetweenthetibialisanteriorandextensorhallucislongusisutilized.Thesuperficialperonealnerveisidentifiedandretractedthroughoutthecase.Theextensorretinaculumisincisedwithcareforrepairattheendofthecase.Theanteriortibialneurovascularbundleisencounteredandretractedlaterally.Thecapsuleisthenincisedandelevatedoffthejoint.Adequateexposureoftheanklejointshouldallowforcompletevisualizationofthemedialandlateralguttersoftheankle.前路入路是大多数TAR植入物最常用的入路;有一种植入物采用外侧入路设计，文献中描述了TAR的后路入路(54)。在踝关节和胫骨前肌和拇长伸肌之间的间隙处作中线切口。腓浅神经在整个病例中被识别和缩回。在病例结束时小心地切开伸肌支持带进行修复。胫前神经血管束与胫前神经血管束接触并向外侧缩回。然后将关节囊切开并抬高。充分暴露踝关节可以使踝关节内侧和外侧沟完全可见。Theoperativesequencesarespecifictoeachimplant,butgenerallyincludethefollowingsteps:(I)placementofanextramedullaryalignmentguidetofacilitatecuts;(II)provisionalpinningofacuttingblocktotheankle;(III)bonycutsofthetibialandtalus;(IV)trialcomponentplacement;and(V)placementoffinalcomponents(Figure1).Intraoperativefluoroscopyiscriticalthroughtheprocess.Inadditiontoplacementofcomponents,theotherdrivingoperativegoalofTARistoappropriatelyaligntheanklejointandthefootunderneaththeankle.Adequatealignmentisachievedthroughacombinationofintraarticulardeformitycorrectionandexternalprocedures,whichallassistinbalancingoftheankleandfoot(Table2).每个植入物的操作顺序是特定的，但通常包括以下步骤:(I)放置髓外对准导向器以方便切割;(II)将切割块临时钉在脚踝上;(III)胫骨和距骨的骨切口;(四)试件放置;(五)最终部件的放置(图1)。术中透视在整个过程中至关重要。除了放置组件外，TAR的另一个驱动操作目标是适当对齐踝关节和踝关节下方的足部。通过关节内畸形矫正和外部手术的结合可以达到适当的对齐，这些都有助于平衡踝关节和足部(表2)。  Figure1Visualizationofthetotalanklereplacementprocedureintraoperatively.(A)Anexternalalignmentguideisplacedtofacilitatebonycuts.(B)Bonycutsaremadeinthetibiaandtalususingthealignmentguide.(C)Thetrialtibialandtalarcomponentsareplacedtodetermineaccuratesizing.(D)Thefinalimplantisplaced.  Table2ConcomitantproceduresduringTAAfordeformitycorrectionProceduresforvarusdeformity ProceduresforvalgusdeformityDeltoidligamentrelease   Deltoid/springligamentreconstructionLateralligamentrepair      LateralligamentrepairAchilleslengthening AchilleslengtheningGastrocnemiusrecession   GastrocnemiusrecessionLateralizingcalcanealosteotomy       Medializingcalcanealosteotomy1stmetatarsaldorsiflexionosteotomyFibularlengtheningosteotomyMedialrelease  Medialcolumnstabilization   •Talonavicularjointcapsulerelease         •Cottonosteotomy   •Posteriortibialtendonrelease        •1sttarsometatarsalfusion   •NaviculocuneiformfusionPeroneuslongustobrevistransfer      PeroneuslongustobrevistransferPosteriortibialtendontoperoneusbrevis   HindfootfusionforrigiddeformityHindfootfusionforrigiddeformity    TalonavicularfusionNaviculocuneiformfusion  Finalradiographsaretakentoensureadequateimplantcontacttoboneandmechanicalalignment.Thewoundisclosedinlayers,withmeticulousattentiontoextensorretinacularrepairtoreducetheriskofbowstringingfromthetibialisanteriortendon,whichcanthreatentheanteriorskin.最后拍X光片以确保植入物与骨有足够的接触并机械对齐。创面分层闭合，并对伸肌支持带进行细致的修复，以减少胫骨前腱弓弦的风险，因为弓弦会威胁到前面的皮肤。ThoughtheanteriorapproachtotheankleismostrelevantformanyimplantsinTARliterature,thereisoneimplant(TrabecularMetalTotalAnkleSystem)thatemploysatransfibularapproach.Inthiscase,anincisionismadeoverlyingthelateralmalleolus,andtheanteriortalofibularligamentisidentifiedandsectioned.Afterthefibulaandanteriortibiaareexposed,anobliquefibularosteotomyisperformedapproximately1cmproximaltothetibiotalarjointline.Followingthefibularosteotomy,theankleisplacedintoanexternalframeandcuttingguidesareplaced.AfterTARimplantation,thefibulaisanatomicallyreducedandfixedusingascreworplate,andtheanteriortalofibularligamentisrepaired.尽管在TAR文献中，许多植入物都采用踝关节前路入路，但有一种植入物(小梁金属全踝关节系统)采用经腓骨入路。在这种情况下，在外踝上做一个切口，识别并切开距腓骨前韧带。暴露腓骨和胫骨前骨后，在胫距关节线近端约1cm处行斜腓骨截骨术。在腓骨截骨术后，将踝关节置入外支架并放置切割导具。TAR植入后，解剖复位腓骨，用螺钉或钢板固定，修复距腓骨前韧带。PostoperativerecoveryprotocolforpatientsfollowingTARcanvarybyinstitution,especiallyinregardtothepatient’sweightbearingtimeline.GenerallyfollowingTAR,thepatientisimmobilizedinashort-legplastersplintandisnon-weightbearingforthefirstfourtosixweeks.Followingdischarge,patientsareputonacourseofpainmedicationconsistingofacetaminophen,non-steroidalanti-inflammatorydrugs(NSAIDs),andalimiteddoseoforalopioids;medicationtopreventvenousthromboembolismmaybeadministeredperthehospitalistsormedicaldoctors’discretion.Atthetwo-weekpostoperativevisit,thesplintandsuturesareremoved,andthepatientistransitionedtoacontrolledanklemotion(CAM)boot.Atthefour-tosix-weekpostoperativevisit,postoperativeradiographsareobtained,andthepatientbeginsfollowingaprogressiveweightbearingprotocol.Atthe8-to10-weekpostoperativevisit,two-monthradiographsareobtained,andifthepatientisfully-weightbearing,theycannowswitchoutoftheCAMboottoasupportivesneaker.Follow-upvisitsandradiographswillcontinueatfourmonths,sevenmonths,andoneyearpostoperatively,thenareperformedannuallyduringsubsequentfollow-upvisits.TAR术后患者的术后恢复方案因机构而异，特别是考虑到患者的负重时间。一般在TAR后，患者用短腿石膏夹板固定，头4-6周不负重。出院后，患者接受一个疗程的止痛药治疗，包括对乙酰氨基酚、非甾体抗炎药(NSAIDs)和有限剂量的口服阿片类药物;预防静脉血栓栓塞的药物可由医院医生或医生自行决定。在术后两周的随访中，拆除夹板和缝合线，并将患者过渡到受控踝关节运动(CAM)靴。术后4-6周随访时，获得术后X线片，患者开始接受渐进式负重治疗。在术后8-10周的随访中，获得两个月的X光片，如果患者完全可以负重，他们现在可以换掉CAM靴，换上支持性运动鞋。术后4个月、7个月和1年继续进行随访和X光检查，随后每年进行一次随访。 OutcomesInthemodernera,TARisassociatedwithexcellentoutcomesintermsofpainreliefandfunction.ThepasttwodecadesofTARresearchhasdemonstratedsignificantimprovementsinclinicalandfunctionaloutcomes,suchasincreasedimplantsurvivorship,decreasedcomplicationandreoperationrates,andimprovementsinfunctionalscoresandperceivedpainrelief.Asaresultoftheseconsiderableadvancements,TARhasbecomeincreasinglypopularasatreatmentoptionforend-stagearthritisandhasraiseddebateaboutitsmeritsoverthecurrentgold-standardtreatmentoption,anklearthrodesis.在现代，TAR与疼痛缓解和功能方面的良好结果相关。过去二十年的TAR研究已经证明了临床和功能结果的显著改善，例如增加了植入物存活率，减少了并发症和再手术率，改善了功能评分和感知疼痛缓解。由于这些相当大的进步，TAR作为终末期关节炎的治疗选择越来越受欢迎，并引发了关于其与目前的金标准治疗选择——踝关节融合术的优点的争论。 OutcomesversusarthrodesisComparedtoarthrodesis,TARhasbeendemonstratedtohavesimilarsurvivorship,betterpainreduction,anddecreasedreoperationrates(55).SeveralstudieshavebeenpublishedcomparingoutcomesofindividualTARimplants(HINTEGRA,SaltoTalaris,STAR,andINBONE)toanklearthrodesis,whichcorroboratefindingsofsurvivorshipandclinicalimprovements(55-58).EvolutionofTARinthepastdecadehasfurtherdemonstrateditsadvantagesoverarthrodesis;third-generationTARimplantshavesignificantlylowerratesofasepticlooseningcomparedtoratesofnonunioninarthrodesis(59).Furthermore,TARpatientsreportgreaterimprovementsinsatisfactionscoresandbetterfulfillmentofpreoperativeexpectationsversusarthrodesis(60).FunctionaloutcomesfollowingTARdemonstratesuperiorresultstoarthrodesisinregardstogait,rangeofmotion,andfunctionalability.MultiplestudiesassessingcomparativegaitanalysisbetweenTARandarthrodesishavedemonstratedmoresymmetricalgaittiming,recoveredbilateralgait,andrestoredgroundreactionforcetransmissioninTARthatbetterreplicatedthatofahealthycontrol(61-63).Further,TARpatientshavegreatertotalarcofmovementcomparedtoarthrodesis,andsubsequentlylesscompensatorymovementinadjacentjoints,allowingforgreaterpreservationofadjacentjointsfromdegenerativechanges(64).Improvedperformanceascendinganddescendingstairs,andbetternegotiationofunevensurfaceshaveadditionallybeencorrelatedwithTAR(65,66).Asmodern,fourth-generationTARimplantreach5-yearand10-yearmilestones,furtherstudiesarenecessarytoreportuponoutcomesandtocomparewithanklearthrodesis.ThoughTARoutcomesarepromising,thereareinherenttrade-offsbetweenthetwoprocedures,andpatientselectionremainsanimportantconsiderationpriortosurgicalintervention. ClinicalandfunctionaloutcomesPatientswhoundergoTARexperiencesignificantimprovementsinpainandphysicalfunction.Assessmentsofpatient-reportedoutcomehaveconsistentlyconfirmedsignificantimprovementsinpainreductionandqualityoflifefollowingTAR(43,67,68).Inaddition,patientsatisfactionfollowingTARishigh,withratesrangingbetween80–97%,buttypicallyexceeding90%(69).FunctionaloutcomesforTARpatientshavebeenassessedthroughvariousmetrics,includingpatient-reportedoutcomescores,clinicalassessmentofrangeofmotion,gaitanalysis,andparticipationinsportspriorandfollowingTAR.Postoperatively,rangeofmotionincreasesonaverageby5–10°,foratotalarcofmotionrangingbetween34–40°(64,70).Patient-reportedoutcomesoffunctionalabilitiesconsistentlydemonstratesignificantimprovementspostoperatively(69);further,patientswithworsepreoperativefunctionhaveshowngreaterimprovementsinoutcomescorescomparedtothosewithhigherpreoperativefunctionscores(71).Moreover,patientshavedemonstrateda20%increasedparticipationinsportsactivitiesfollowingTAR,thoughusuallytheseactivitieswere“low-impact”,suchasswimming,golf,andcycling(72,73).Thoughhigh-impactsportsarenotadvisedtopreservethelongevityofTARimplants,patientscanstillexpecttoachievemarkedimprovementintheirdailyfunctionandabilitiesinlow-impactsports. ImplantsurvivorshipCurrentsurvivorshipforTARimplantsrangesfrom70%to98%at3–6yearsand80%to95%at8–12yearspostoperatively(Table3)(69).Comprehensivemeta-analysesreportinguponoutcomesforTARaresparse;themostrecentofwhichcalculatedanadjustedsurvivorshipof90%at5-yearacross1,105TARs(13).Theseanalyses,however,arelimitedtosecondandthirdgenerationimplants,anddonotreporttheoutcomesofmanymodernimplantscurrentlyusedbysurgeons.Fourth-generationimplantssuchastheVantage,INFINITY,andCadencearewidelyusedbycurrentTARsurgeons,buttheirmid-tolong-termreportsonoutcomesarelimitedbytheirrelativenovelty.Earlyreportsonoutcomesforthesenovelimplantsarepromising,withsurvivorshiprangingbetween93.7%to100%at2years(20,32,33,84).However,itisimportanttonotethatmostTARproceduresarecarriedoutinhigh-volumehospitalsinmetropolitanareasintheUnitedStates,andtendtobeperformedbysurgeonswithhighvolumesofTARexpertise(85,86).Inspiteofthis,lowvolumehospitalsforTARhavealsobeenshowntoachieveimprovedoutcomesandgoodsurvivorship(87).  Table3Summaryofrecentand/orpopulartotalanklereplacementsandtheiroutcomesImplant    Study       No.ofimplantsFollow-up(years),median(IQR)   Survivorship    ReoperationrateAgility     Knecht,2004(74)    132 9.0(7.0to16)        89.00%    NotrecordedRaikin,2017(22)     115  9.1(4.0to14)  78.20%        NotrecordedCadence   Fram,2022(75)       58    Minimum2        94.80%    20.70%Kim,2023(30)48    2.8(2.0to4.2) 93.80%    6.30%HINTEGRA    Yang,2019(76)       210 6.4(2.0to13.4)        91.70%    9.00%Yoon,2022(77)       151 11.3(10to17) 93.50%        22.50%INBONEI       Adams,2014(17)    1943.7(2.2to5.5)        89.00%    25%Harston,2017(78)   149 5.9(4.0to9.4) 90.60%        13.40%INBONEII      Lewis,2015(79)      56  2.1(1.3to2.9)        97.40%    15.90%Gagne,2022(20)     51    6.4(5.0to9.0) 98.00%        7.80%INFINITY       Saito,2018(33)       64  2.0(1.5to3.3)        95.30%    17.10%Cody,2019(80)       159 1.6(1.0to3.1) 90.00%        NotrecordedSaltoTalaris     Stewart,2017(23)   1066.8(5.0to9.6)        95.80%    19.00%Day,2020(22)85    7.1(5.0to12)  97.60%    21.20%STAR      Wood,2003(81)      143 7.3(5.0to13.0)        80.30%    NotrecordedClough,2019(82)    87    15.8(11.1to24.5)   76.16%        NotrecordedZimmer    Barg,2018(83)        55    2.2(1.9to2.6)        93.00%    18.20%Maccario,2022(29)86    5.4(5.0to7.5) 97.70%        NotrecordedIQR,interquartilerange.  RevisionsandriskfactorsInthecaseofTARfailure,revisionoptionsincluderevisionTAR,tibiotalararthrodesis,andinmoreseverecases,tibiotalocalcaneal(TTC)fusionorbelowkneeamputation(BKA).ThemostcommonindicationsforrevisioninTARareduetoinfection,asepticloosening,andsubsidence.Revisionisclassicallydefinedasimplantfailuresnecessitatingareturntotheoperatingroomforexchangeorremovalofthetibialand/ortalarimplant(17,88),whereasreoperationsarecharacterizedasallotherreturnstotheORthatpreservethemetalliccomponents.OutcomesforrevisionTARsdemonstraterelativelygoodsurvivorshiprangingbetween80%to97%,withimprovingsurvivalratesinrecentyearsfollowingtheintroductionofrobust,stemmedimplantsthataccountforlossofbonestock(36,89,90).RevisionTARhasbeenfoundtopreserveanklerangeofmotionandprotecttheadjacentjointsfromcompensatoryload,offeringgreaterfunctioncomparedtorevisiontoanklearthrodesis(91,92).Moreover,patient-reportedoutcomescoresfollowingrevisionTARshowedgreaterimprovementscomparedtoanklearthrodesis,yetfailedtoreachthethresholdofimprovementobservedwithprimaryTAR(89,93).TibiotalararthrodesisfollowingfailedprimaryTARhasalsohadsatisfactoryoutcomesandsurvivorship.Inonemeta-analysisof193patientswithfailedTARsconvertedtoanklearthrodesis,84%hadsuccessfulfusion;thoughtheseratesrangedfrom50%to100%whensubcategorizedbymodeoffusion(94-96).BothrevisionTARandanklearthrodesisareviabletreatmentoptionsfollowingfailedTAR,thoughdifferencesinfunction,pain,andsurvivorshipdoexistbetweenthetwoprocedures.DeterminingthepatientfactorsthatmaycontributetoimplantfailureisanimportantareaofresearchinTAR.RecentassessmentsofpatientdemographicsandTARoutcomeshaveidentifiedprioranklefusionandipsilateralhindfootfusionasriskfactorsforfailure,likelyduetotheincreasedstressesplacedonthefootandimplant(18,97,98).Othertheorizedriskfactorscontributingtofailureincludeactivitylevel,bodymassindex(BMI),preoperativediagnosisofinflammatoryarthritis,andsevereankledeformity,butreportsontheirassociationsarevaried(18).Younger,moreactivepatientshavebeenthoughttobeatgreaterriskforfailureduetogreaterestimatedstressandlongerimplantlifetime,butlargecohortanalysisofTARoutcomesinyoungerpatientsdidnotidentifyanyincreasedrisk(18,38).Similarly,highBMIhasalsobeenidentifiedasapotentialriskfactorforfailure,butthisassociationwasnotidentifiedinrecentoutcomeassessments(18,47).PreoperativediagnosisofinflammatoryarthritishashadconcernsforimpactonTARsurvivorshipduetoitscorrelationwithpoorbonestock,increasedinflammatoryresponse,andconfoundinginfluenceofimmunomodulatorymedication(99,100).However,currentanalyseshavereportedsimilaroutcomesintermsofsurvivorship,complications,andreoperationsbetweenpatientswithandwithoutinflammatoryarthritis(18,100).Finally,patientswithseverevarusorvalgusdeformityhavedemonstratedcomparableresultsinrecentstudies,solongasthedeformityiscorrectedintraoperatively(18,44,45).Furtherstudieswithlongerfollow-uparenecessarytocorroboratewiththecurrentliteratureaboutriskfactorsinTAR.Survivorship,painscores,andclinicaloutcomeshavecontinuedtoimproveinnewergenerationsofimplants,whilecomplicationsandreoperationrateshavedecreased.However,despitethetrendsinimprovementsforTAR,outcomesstudiesformodernimplantsareinherentlylimitedbythelow-qualityofevidenceandinsufficiencyoflong-termstudies. ComplicationsComplicationsassociatedwithTARincludedelayedwoundhealing,infection,periprostheticfracture,impingement,andperiprostheticlucencyandcysts.Treatmentofthesecomplicationscaninvolvenonoperativeintervention,reoperation,revision,orconversiontoanklefusion/amputationbasedoncaseseverity.CategorizationofTARcomplicationsbasedontheirassociatedclinicaloutcomeswasfirstproposedbyGlazebrooketal.,andestablishedthreecategories:high-grade,medium-grade,andlow-grade(101).Thiscategorizationcanhelpguidesurgeondecisionmakingandinterventionplansattheonsetofcomplications.Wound-healingcomplicationsareaprominentconcernintheearlypostoperativeperiodandcanjeopardizetheintegrityoftheimplant.Wound-healingcomplicationsmaybeminorandhavecompleteresolutionofsymptomsfollowingtreatmentwithlocalwoundcareororalantibiotics.Moreseverewoundissuesmayrequireareturntotheoperatingroomformoreaggressiveintervention,suchasirrigationanddebridement,vacuum-assistedclosure,orflapcoverage.Longeroperativetimeandlongertourniquettimehavebeenassociatedwithhigherratesofwoundcomplications,aswellaspatientswithadiagnosisofprimaryosteoarthritis,historyofdiabetes,andhistoryofsmoking(102-104).Periprostheticjointinfection(PJI)followingTARhasareportedincidenceof0%to6.7%incurrentliterature(13,105,106).PJIcanbedividedintotwocategories:acutePJIandchronicPJI.AcutePJIischaracterizedasinfectionseitheroccurringintheearlypostoperativeperiodoroccurringwithsuddenonsetinapatientpreviouslydoingwell,withsymptomdurationbelow4weeks(106,107).Acuteinfectionsaretypicallytreatedwithdebridement,antibiotics,andimplantretention(DAIR)withpolyethyleneexchange.Thelong-termoutcomesfollowingDAIRhavebeensuboptimal,withrecentreportscitingafailurerateof54%andhighratesofreinfection(107).However,ithasbeendeterminedthatearliersurgicalinterventionfollowingtheonsetofsymptomsisdirectlycorrelatedsuccessrateoftreatmentwithDAIR(107).Chronicinfectionsrequireatwo-stagerevision,consistingfirstofcompleteremovalofallimplantsandinsertionofanantibioticcementspacer,withacourseofintravenousantibioticsforatleastsixweeks.Dependingonthepatient’scondition,statusofinfection,andavailablebonestock,thesecondstageoftherevisionmayinvolvereimplantationofarevisionTARimplant,conversiontoarthrodesis,permanentretentionofthecementspacer,orbelow-kneeamputation.Currently,reportsdetailingoutcomesfollowing2-stagerevisionforchronicPJIarelimited.Inonesingle-centerseriesofanklePJIin34patients,the10patientstreatedwith2-stagerevisionhadareinfectionrateof0%(105).Similarly,ameta-analysisof105casesofanklePJIacross6studiesreporteda0%reinfectionrateinthe22patientstreatedwith2-stagerevision(108).LargercohortstudiesarenecessarytodrawdefinitiveconclusionsonoutcomesfollowinganklePJI,butcurrentliteratureindicates2-stagerevisionasaneffectiveinterventionforeradicatinginfectionfollowingTARPJI.Intraoperatively,themostcommoncomplicationduringTARisperi-prostheticfracture,typicallymedialorlateralmalleolarfracture(109).Medialmalleolarfracturesaremostfrequent,withanincidencerateof6%,whilelateralmalleolarfractureshavearateof1%(109);however,theoccurrenceofintraoperativefractureshasbeenshowntodecreasewithincreasedsurgeonexperience(110,111).Intraoperativefracturesshouldbetreatedwithopenreductioninternalfixation,thoughpatientscanachieveoptimaloutcomeswithoutfixationiffractureisnondisplaced(112).IncasesofmedialmalleolarthinningduringbonyresectionatthetimeofindexTAR,prophylacticfixationisrecommended.Postoperatively,theincidenceoffracturesisbetween2%to4%,primarilyaroundthemedialmalleolus,followedbythetibialdiaphysis,talus,andfibula(113,114).Operativemanagementisrecommendedforallinstancesofpostoperativeperiprostheticfracture,asnonoperativetreatmenthasbeendemonstratedasapredictoroftreatmentfailureinTAR(114).Periprostheticfractureswithimplantstabilitycanbesuccessfullytreatedwithopenreductionandinternalfixation;fracturewithanunstableimplantshouldbeindicatedforrevisionTARorconversiontoarthrodesis(113,114).SymptomaticbonyimpingementisthemostcommonindicationforreoperationfollowingTAR,andonsetofimpingementislargelycorrelatedtoinadequategutterdebridementatthetimeoftheindexprocedure(22,115).Therateofreoperationforsymptomaticimpingementcurrentlycitedinliteraturerangesfrom7%to18%(18,115,116).Inasingle-centerstudyforincidenceofsymptomaticimpingementin489TARs,itwasdeterminedthatincidencedroppedfrom18%to2%ifthepatientsunderwentgutterdebridementatthetimeoftheindexTAR(116).Otherfactorsassociatedwithimpingementincludeimplantmalpositionorsubsidence,persistentmalalignment,overstuffingoftheanklejoint,heterotopicossification,andshiftingofthepolyethyleneinsert(116).Gutterimpingementistypicallytreatedwithopenorarthroscopicgutterdebridement,however,symptomaticimpingementduetoimplantmalposition,subsidence,orpersistentmalalignmentmayrequirefurthersurgicalintervention,includingpolyethyleneexchange,revisionofthemetalliccomponents,ordeformitycorrection.AsepticlooseningandsubsidencecontinuetobethemostcommoncausesofimplantfailureinTAR(93,101,117),thoughtheincidenceoflooseningand/orsubsidencevariesintheliterature.Implantlooseningandsubsidencecanbeattributedtoseveralfactors:progressiveosteolysis,poorbonequality,poorinitialfixation,implantmalposition,andincreasedcontactpressure(118-120).Additionally,biomechanicalmodelsofimplantfixationdemonstratedthatimplantdesignmayaffectimplant-bonemicromotionandsubsequentosseousintegration(121),thoughfurtherstudiesarewarrantedtoinvestigatethisassociationacrossimplanttypes.Symptomaticasepticlooseningand/orsubsidencetypicallyistreatedwithrevisionofthetibialand/ortalarcomponentifsufficientbonestockisavailable.Otherwise,ifrevisionisnotfeasible—duetoinsufficientbonestock,severecomponentsubsidence,orinsufficientsofttissueenvelope—arthrodesisisaviablealternative.Radiographicabnormalities,suchaslucenciesandperi-prostheticcysts,arecommonfindingsinpostoperativeradiographs.Thedevelopmentofradiographiclucenciesandosteolyticcystshasbeenassociatedwithseveralpotentialfactors,includingimplantmicromotion,implantpositioning,synovialfluidpressure,andimmunologicresponseinstigatedbypolyethyleneinsertwearorbybonynecrosis(122-125).Thoughtheassociationofmanyofthesefactorswithosteolysishasbeenwelldescribedinhipandkneeliterature(123,125,126).furtherclinicalstudiesarenecessarytolinktoTARs.Althoughperi-implantlucencycanbeobservedinaround30%ofanklesfollowingTAR,lucencydoesnotalwaysrequiresurgicalintervention(127,128).Radiolucenciesinpostoperativeradiographsshouldbemonitoredforprogressionandcorrelatedtoclinicalassessmenttodetermineifsurgicalinterventioniswarranted(124,125).Peri-prostheticcystsarelesscommonthanradiolucencies,butprevalentnonetheless.Peri-prostheticcystsaretypicallyevaluatedwiththoroughclinicalexaminationandradiographicimagingtoassesssymptoms,cystsizeandlocation,progression,andimminentthreattoimplantintegrity;patientswithassociatedpainshouldalsobeworkedupforinfection(129,130).Incidencesofcystswithsignificantprogressionorsymptomsofpaincanbetreatedwithcurettageandbonegrafting,orwithrevisionTARorarthrodesisincasesofseverebonelossorimplantsubsidence(129).Theinterventionofsymptomaticperi-prostheticcystswithcurettageandgraftinghasdemonstratedasuccessrateof90%(131).Theoptimaltreatmentforperi-prostheticcystsandradiolucencies,however,hasyettobedetermined;interventionoptionsarestronglydependentuponpatientsymptoms,cystorradiolucencysizeandlocation,andintegrityofimplantandsurroundingbonestock. FutureWiththemountingpopularityofTARoverthepastdecade,thereisconsiderableinteresttocontinuetoinnovate,refine,andimprove.TheevolutionofTARoverits50yearsofexistencehasprovidedtremendousinsightforimplantdesign,surgicaltechniqueandplanning,andoverallimprovementsofoutcomes.ThoughthemostrecentfourthgenerationofTARimplantshavesucceededinoptimizingclinical,radiographic,andfunctionaloutcomes,therestillexistsareasoffurtherdevelopmentinTAR.随着TAR在过去十年中越来越受欢迎，人们对继续创新、改进和改进产生了相当大的兴趣。TAR在其50多年的发展历程中，为植入物设计、手术技术和计划以及整体预后的改善提供了巨大的见解。尽管最近的第四代TAR植入物已经成功地优化了临床、放射学和功能结果，但TAR仍有进一步发展的领域。WhiledemandforTARhasincreasedacrosstheUnitedStates,thenumberofsurgeonswhoregularlyperformTARproceduresisfairlylimited(85,86).TARisassociatedwithasteeplearningcurvethatinfluencesoutcomes,aswellassurgicaltimeandriskofintraoperativefracture(132).Thisbarrierhasledtothedevelopmentofpatient-specificinstrumentation(PSI)toassistinminimizingthelearningcurveandimprovingoutcomesfornaïveTARsurgeons.ResultsofPSIusageinTARhavedemonstratedreducedoperativetime,accuratepresurgicalplans,andaccuratejointalignment(133-135).Recently,twoadditionalimplantshaveintroducedtheirownPSIsystems,suggestingthatPSImaybecomeanestablishedtoolforanklereplacementsurgeons.However,therearestillsomelimitationsthatprevailinthecurrentPSItechnology,includinginaccuraciesintibialsizingandlimitationsinpresurgicalplanningforcaseswithseveredeformity.AlthoughthepaucityofcurrentliteratureassessingPSIinTARmakesitdifficulttodrawfiniteconclusions,initialevidencedemonstratespromisingresultsforPSIasareliableandaccuratetoolforTAR.虽然美国各地对TAR的需求有所增加，但定期进行TAR手术的外科医生数量相当有限(85,86)。TAR与陡峭的学习曲线相关，影响预后、手术时间和术中骨折风险(132)。这一障碍导致了患者特异性器械(PSI)的发展，以帮助naïveTAR外科医生最大限度地减少学习曲线并改善结果。在TAR中使用PSI的结果显示减少了手术时间，准确的术前计划和准确的关节对齐(133-135)。最近，又有两个植入物引入了自己的PSI系统，这表明PSI可能成为踝关节置换手术的一种成熟工具。然而，目前的PSI技术仍然存在一些局限性，包括胫骨尺寸的不准确性和严重畸形病例的术前计划的局限性。虽然目前评估TAR中PSI的文献很少，因此很难得出有限的结论，但初步证据表明PSI作为TAR可靠和准确的工具有希望的结果。SuccessfuloutcomesachievedinTARhaspromptedinterestinexpandedanatomy-replicatingimplants,suchaswiththetotaltalusreplacement(TTR).TTRwasdesignedasanalternativetreatmentoptionforpatientswithseveretalarAVN,talardomecollapse,orsignificantlossoftalarbonestock,whenusedinadjunctwithtotalanklearthroplasty(TAA)(136).Althoughthefirstreportofasynthetictalarprosthesiswasperformedin1997,foraseriesof16patientswithAVN,significantattentiontowardsTTRonlyrecentlydevelopedinthepasttenyearsinparalleltothegrowingprevalenceofthree-dimensional(3D)printing(137).CurrentliteraturereportingTTRoutcomesisscarce,typicallylimitedtocasereportsandanecdotalfindings,whichmakesitdifficulttodeterminethefeasibilityorrelativesuccessoftheprocedure.Inameta-analysisofoutcomesin196TTRankles,resultsreportedarelativelylowincidenceofrevisions(10ankles),improvementindorsiflexion,andimprovedpatient-reportedoutcomesatfour-yearfollow-up(138).However,thereareseveralchallengesthatimpactthefeasibilityofTTR,includingthedevelopmentofadjacentjointarthritis,prosthesisinstability,andPJI(136,139).Moreover,followingTTRfailure,salvageoptionsarelimitedandtechnicallydemanding.Duetotheshort-termfollow-upandsmallsamplesizesfeaturedinTTRliterature,definitiveconclusionsonsurvivorship,outcomes,andcomplicationsinthelongtermareimpossible.Currently,TTRshowspromiseasatreatmentoptionforpatientswithseveretalarpathology,butfurtherstudieswithadequatefollow-uparenecessarytovalidatecurrentfindings.TAR取得的成功结果引起了人们对扩展解剖复制植入物的兴趣，例如全距骨置换术(TTR)。TTR被设计为严重距骨AVN、距骨圆顶塌陷或距骨缺损患者的替代治疗选择，当与全踝关节置换术(TAA)联合使用时(136)。虽然合成距骨假体的第一个报道是在1997年，针对一系列16例AVN患者，但在过去的十年里，随着三维(3D)打印的日益普及，对TTR的关注最近才开始出现(137)。目前报道TTR结果的文献很少，通常仅限于病例报告和轶事发现，这使得很难确定该手术的可行性或相对成功。在一项对196个TTR踝关节结果的荟萃分析中，结果报告了相对较低的修复发生率(10个踝关节)，背屈改善，以及四年随访中患者报告的改善结果(138)。然而，存在一些影响TTR可行性的挑战，包括邻近关节关节炎的发展、假体不稳定和PJI(136139)。此外，在TTR失败后，救助选择有限且技术要求高。由于TTR文献的随访时间较短，样本量小，因此无法对长期的生存率、结局和并发症得出明确的结论。目前，TTR有望作为严重距骨病变患者的治疗选择，但需要进一步的研究和充分的随访来验证当前的发现。 ConclusionsTARhasundergonemarkedinnovationinthepast50years,andhascontinuedtogrowinpopularityinthepastdecade.ThethirdandfourthgenerationsofTARimplantscurrentlycirculatingthemarkethaveimplementedimprovementsinbonefixation,mechanicalalignment,andsofttissuebalancethathavecontributedtoincreasesinsurvivorship,functionaloutcomes,andpainresolution.ThecontinualrefinementofprosthesisdesignandsurgicaltechniquehaveallowedindicationsforTARtoexpand,andcomplicationsassociatedwiththeproceduretodecrease.CurrentoutcomesforTARdemonstrateitsmeritasaviablealternativetreatmentoptiontoanklearthrodesisinthesettingofend-stageankleosteoarthritis.FutureinnovationinthefieldofTARlookstoexpandupontheimplementationofPSIandrevisionTARsystemstofurtherimproveoutcomesandguidesurgicalapproach.TAR在过去50年中经历了显著的创新，并在过去十年中继续普及。目前市场上流通的第三代和第四代TAR植入物在骨固定、机械对准和软组织平衡方面进行了改进，有助于提高生存率、功能预后和疼痛缓解。假体设计和手术技术的不断改进使得TAR的适应症得以扩大，与手术相关的并发症得以减少。目前的结果表明，在终末期踝关节骨关节炎的治疗中，TAR作为踝关节融合术的一种可行的替代治疗方案。TAR领域的未来创新将在PSI实施和TAR系统修订的基础上进行扩展，以进一步改善结果并指导手术方法。

全膝关节置换治疗膝关节外翻畸形大于90度(2019)Totalkneearthroplastyforavalgusdeformityangleof>90degrees:Acasereport GuoJ,CaoG,ZhangY,SongW,QinS,MaT,WangY,YangW.Totalkneearthroplastyforavalgusdeformityangleof>90degrees:Acasereport[J].Medicine(Baltimore),2019,98(23):e15745.转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/31169673/转载文章的原链接2：https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6571272/ AbstractRationale:Valguskneesarerelativelyrareintheclinic.Treatmentsforvalgusdeviations>90°representasurgicalchallengetoachieveabalancebetweenthesofttissueandboneandpreventnervedamage.膝外翻在临床上比较少见。外翻偏差>90°的治疗是实现软组织和骨骼之间平衡并防止神经损伤的外科挑战。 Patientconcerns:A63-year-oldwomanwithvalgusdeviations>90°inbothkneescomplainedthatshehadbeenunabletowalkfor50years.一名63岁女性，双膝外翻>90°，自诉已不能行走50年。 Diagnoses:Congenitalmalformationvalgusdeformity.先天性外翻畸形 Interventions:Bilateraltotalkneearthroplasty(TKA)wasperformedusingarotatinghingekneeinstrumentfromEndo-Modelforaxialcorrectionandstabilizationofthejoint.双侧全膝关节置换术(TKA)采用Endo-Model的旋转铰链膝关节器械进行轴向矫正和关节稳定。 Outcomes:Thepatientfullyrecovered3monthsaftersurgery.Atthefollow-up6yearsaftertheoperation,thefunctionofthekneejointclearlyimproved.Thekneesocietyscore(KSS)increasedfrom35to90.术后3个月患者完全康复。术后随访6年，膝关节功能明显改善。膝关节协会评分(KSS)由35分上升至90分。 Lessons:Constrainedimplantsarecommonlyusedtostabilizethejointandcorrecttheboneaxisinpatientswithsevereligamentalinstability,grossdeformity,boneloss,andextremedeviationofthestraightlegaxis.Intraoperativeexplorationofthecommonperonealnerveandthepostoperativeflexedpositionofthekneejointscouldhelppreventnerveinjuries.对于严重韧带不稳、严重畸形、骨质缺失和直腿轴极度偏离的患者，限制性假体通常用于稳定关节和矫正骨轴。术中探查腓总神经及术后膝关节屈曲位置有助于预防神经损伤。 Keywords:totalkneearthroplasty,valgusdeformity,hingeknee 1.IntroductionTotalkneearthroplasty(TKA)isusedtotreatkneevalgusdeformity,andapproximately10%ofallpatientswhorequireTKApresentwithvalgusdeformity.[1,2]AccordingtotheKeblishclassification,thefemorotibialangle(FTA)canbemeasuredonthex-rayimageofthevalgusdeformity;amildangleis<15°,amoderatedegreeis15°to30°,andaseveredeformityisanangle>30°.[3]Becauseofthedifferenttensionsofsofttissueandbonedefects,differentprosthesescanbeselected.Formilddeformitiesandsomemoderateandseverekneevalgusdeformities,wecanfirstreleasethelateralcollateralligamentthroughtenolysisofthesofttissuethenreleasetheposterolateralarticularcapsule,theiliotibialbandandthelateralheadofthegastrocnemius,bicepstendon,andpoplitealtendontissue.Thus,soft-tissuebalancecanbeobtained.Formoderateandsomeseverevalguskneedeformities,posteriorcruciate-retainingtotalkneeprostheses,constrainedcondylarkneeprostheses,orvarus-valgusconstrainedimplantscanbeusedtoobtainagoodresult.[4]Someofthemoreseverevalguskneedeformitieswithbonedefectsneedtobefixedwithanextensionrodandtheplacementofaspacerblocktoachievebalanceandstability.However,forsomepatientswithseveredeformitiesofthevalgusknee,surfaceprostheseswithsofttissuereleaseareunabletoachievebalanceandstability.Thesecasesoftenrequiretheuseofahingekneeprosthesistosolvetheproblem.Hingekneeprostheseswithgoodcoronalstabilitycanstablyreplacesoft-tissuebalance,butcomplicationsofloosenesscanoccur,whicharemainlyduetosagittalalignmentbecausethesagittalplaneoutputsahighamountofpower;thispulleventuallyleadstoprosthesisloosening.[5–7]Nonetheless,thelooseningrateoftheEndo-Modelhingeprosthesisreportedinthepreviouslypublishedliteratureislow.[8–11][3]KeblishPA.Thelateralapproachtothevalgusknee.Surgicaltechniqueandanalysisof53caseswithovertwo-yearfollow-upevaluation.ClinOrthopRelatRes1991;271:52–62.全膝关节置换术(TKA)用于治疗膝关节外翻畸形，大约10%需要全膝关节置换术的患者存在外翻畸形[1,2]。根据Keblish分类，可以在外翻畸形的X线图像上测量股胫角(FTA);轻度畸形为<15°，中度畸形为15°至30°，重度畸形为>30°[3]。由于软组织张力和骨缺损的不同，可以选择不同的修复体。对于轻度畸形和部分中重度膝外翻畸形，可先通过软组织松解术松解外侧副韧带，然后松解后外侧关节囊、髂胫束和腓肠肌外侧头、二头肌肌腱、腘肌腱组织。因此，可以获得软组织平衡。对于中度及部分重度外翻膝关节畸形，可采用后交叉韧带保留假体的全膝关节假体、限制性髁膝关节假体或内外翻限制性假体，均可获得较好的效果[4]。一些更严重的外翻膝关节畸形伴骨缺损需要用延伸棒和放置间隔块来固定，以达到平衡和稳定。然而，对于一些外翻膝关节严重畸形的患者，具有软组织松解的表面假体无法达到平衡和稳定。这些病例通常需要使用铰链膝关节假体来解决问题。具有良好冠状面稳定性的铰链式膝关节假体可以稳定地替代软组织平衡，但由于矢状面输出功率大，因此可能出现松动并发症，这主要是由于矢状面对准所致;这种拉力最终会导致假体松动[5-7]。然而，先前发表的文献报道的endomodel铰链假体的松动率很低[8-11]。Kneevalgusdeformitiescanbecongenitalormayoccursecondarytoconditionssuchasosteoarthrosis,rheumaticdiseases,andposttraumaticarthritis,ortoanovercorrectionfollowingavalgusosteotomy.[4]Valgusdeviations<20°,whichaccountforapproximately95%ofallvalgusknees,arerelativelyeasytocorrectwithsurgery.[2]However,thecorrectionofvalgusdeviations>20°isachallengingundertakingforjointsurgeons.[2,12]Herein,wereportacaseofseverevalgusdeformitywithavalgusdeviation>90°ina63-year-oldwomanwhowassuccessfullytreatedwithTKA.Tothebestofourknowledge,thisisthefirstdocumentedcaseofsuccessfultreatmentofa>90°valgusdeformitywithTKA.Thepatientandherfamilyhaveconsentedtothepublicationofthisarticle.膝外翻畸形可能是先天性的，也可能是由骨关节病、风湿性疾病和创伤后关节炎等继发疾病引起的，或者是外翻截骨术后矫治过度引起的[4]。外翻偏差<20°约占所有外翻膝关节的95%，相对容易通过手术矫正[2]。然而，对于关节外科医生来说，矫正>20°的外翻是一项具有挑战性的工作[2,12]。在此，我们报告一例63岁女性外翻畸形，外翻偏度>90°，经TKA成功治疗。据我们所知，这是第一例用TKA成功治疗>90°外翻畸形的病例。患者及其家属已同意发表这篇文章。 2.CasereportA63-year-oldwomanpresentedatourhospitalwithcongenitalmalformationvalgusdeformity>90°(Fig.1A,B).Anx-rayofthekneeshowedamalformedfemoralcondyleandtibialplateauwithseverebonedefects(Fig.2).AccordingtotheKeblishclassification,thiscasewasclassifiedasaseveredeformity.[3]Thepatienthasnotbeenabletowalknormallysincetheageof12.Themusclestrengthofthequadricepswaslow.Aphysicalexaminationshowedthatallligamentsaroundthekneewereslack.Throughtheaboveexamination,thepatient'skneesocietyscore(KSS)scorewasassessedtobe35.[13]Thekneeextensionreached90°,andtheflexionreached80°.  Figure1(A,B)Preoperativephotographofthepatientshowingseverekneevalgusdeformity.  Figure2Preoperativex-rayradiograph(nonweight-bearing)showingmalformationsandbonydefectsinthefemoralcondyleandthetibialplateau.  Beforetheoperation,wecreatedathreedimensionalmodelofbothknees,simulatedthepatellatrajectoryandcarefullyexaminedthepatient'ssofttissuetightness.Duetothepresenceofseverebonedefectionandthesevererelaxationofthemedialandlateralsofttissuedevices,theEndo-Modelrotatinghingekneeprosthesiswaschosenforthepatient,andabilateralTKAwasperformed.Thekneejointswereexposedviaamedialparapatellarapproachtoachieveagoodviewbecausewedidneedtoworryaboutsoft-tissuebalance.Thefemoralcondyleswereseverelydeformedwithasmalllateralfemoralcondyleandarelativelylargemedialfemoralcondyle.Tibialextorsion,lateraldislocationofthepatella,andseveredegenerationofarticularsurfacesofthefemur,tibia,andpatellawerealsoobserved.Bonehyperplasiaandsyndesmophyteformationaroundthejointwereobservedalongwiththewornmedialandlateralmenisci.Theanteriorandposteriorcruciateligamentswerealmostinvisible.Afterresectionofthehyperplasticosteophyteandsynovialmembrane,theiliotibialbandwasfirstreleased,thenthelateralretinaculumwasreleased.Subsequently,thelateralligamentwasdirectlyincised.Becausetheligamentsaroundthekneewereslack,theEndo-Modelrotatinghingekneeprosthesiswasused.Basedonthepreoperativex-ray,thefemoralcanalinthemedialfemoralcondylewasselectedastheentrypointfortheintramedullaryguide.Aftertheinternalrotation,externalrotation,alignment,andtautnessofthekneejointweretestedtomeetthephysiologicalrequirements,theGermanyLinkkneeprosthesis(leftknee:tibiasize55 mm/160 mm,femursize55 mm/160 mm,polysize16mm;therightkneeprosthesiswasthesamesizeastheleft)wasinstalled.Fullreleaseofthepatellarlateralretinaculumandstrengtheningofthepatellarmedialretinaculumwereperformedtocorrectthelateralpatellardislocation.Aftersurgery,thekneeswereingoodalignment.Theankleactivitywasnormal.Onedayaftersurgery,thepatientwasunabletodorsiflextheanklejoints.Thenervusperoneuscommuniswassuspectedtohavebeendamagedbytraction.Thepatientreceivedanoralmethylaminedispersibletabletandperformedjointfunctionalexercises.Oneweekaftersurgery,themovementsofthekneejointrangedfrom5°to90°.Thex-rayimageshowedanappropriateprosthesisposition(Fig.3).  Figure3Postoperativex-rayradiographshowingtheimplantedprosthesis.  Theonlypostoperativecomplicationwasaninjurytotheperonealnerve,whichledtolossofdorsiflexionatbothanklejoints.However,thepatientwasabletowalkwiththeuseofwalkingaids.Thepatientwasregularlyfollowedup,andtheanklemotiondeficitwasfoundtobecompletelyrecovered3monthsaftersurgery.Atthefollow-up6yearsaftertheoperation,thekneeextensionreached180°,kneeflexionreached125°,andtheactivejointfunctionclearlyimproved(Fig.4).TheKSShadimprovedto80atthe2-yearfollow-up,87atthe4-yearfollow-up,and90at6-yearfollow-up.  Figure4Postoperativephotographafter18monthsshowingcompleterecoveryofdorsiflexion.  3.DiscussionAprimaryTKAforavalguskneedeformityof>20°representsachallengefororthopedicsurgeons.[12]Herein,wepresentourexperiencewitha63-year-oldwomanwithaseverevalguskneedeformityangle>90°,whichwasclassifiedasaseveredeformity.Duringsurgery,wereleasedthelateralcollateralligamentsofttissuesandexcisedthemedialandlateralmeniscusandtheremainingcruciateligament.Arotatinghingekneeinstrumentwasusedtocorrecttheboneaxisandstabilizethejoint.TheuseofhingedimplantsinprimaryTKAshouldberestrictedtopatientswithseverebonydeformitiesorligamentousinstability,especiallyinelderlypatients.[14]ConstrainedimplantsarefrequentlyusedforprimaryTKAinpatientswithmoderateandseveregenuvalgum(>10°).[15]ConstrainedTKAiscommonlyperformedtostabilizethejointandcorrecttheboneaxisinpatientswithsevereligamentalinstability,grossdeformity,boneloss,andextremedeviationofthestraightlegaxis.Inthepresentcase,arotatinghingekneeprosthesiswasselected.外翻膝畸形>20°的原发性全膝关节置换术对骨科医生来说是一个挑战[12]。在此，我们报告了一位63岁女性的经验，她的膝关节严重外翻畸形角度>90°，被归类为严重畸形。在手术中，我们松解了外侧副韧带软组织，切除了内侧和外侧半月板以及剩余的交叉韧带。使用旋转铰链膝关节器械矫正骨轴并稳定关节。在原发性全膝关节置换术中使用铰链式植入物应仅限于严重骨畸形或韧带不稳定的患者，尤其是老年患者[14]。限制性假体常用于中度和重度膝外翻（>10°）患者的初次TKA[15]。对于严重韧带不稳、严重畸形、骨质流失和直腿轴极度偏离的患者，通常采用限制性TKA来稳定关节和矫正骨轴。在本病例中，选择了旋转铰链膝关节假体。AmedialorlateralparapatellarapproachcanbeusedtoperformTKAforvalguskneedeformities.Thelateralpatellarincisioniscommonlyusedinmild-to-moderatevalguskneedeformitiestosimplyreleasethelateralstructure.Giventhepositionofthepatellainthepresentcase,thelateralparapatellarapproachwasnotsuitabletogainadequateexposureofthekneejoint;thus,themedialparapatellarapproachwasused.InjurytotheperonealnerveisacommoncomplicationofTKA.TheperonealnerveinjuryiscommonwhenTKAisperformedtocorrectvalguskneedeformities,withanincidenceof2%to3%.[16–19]Weshouldpaymoreattentiontothetensioninthenerve,whichcouldbealleviatedbycuttingoffthefibularhead,ifnecessaryinosteotomy.Postoperatively,thekneeswereplacedin10°offlexionfor3to4daystopreventstretchingoftheperonealnerve,andactiveandpassiverange-of-motionexercises(rangefrom10°to70°)wereallowed.[20]Inthepresentcase,basedonthepreoperativeevaluationofthesurgicalprocedure,webelievedthattheperonealnervewouldnotbetransected,andthuswedidnotexposetheperonealnerveduringtheoperation.However,postoperatively,thepatientwasunabletodorsiflextheankle.Tractioninjurytothecommonperonealnervemayresultinthelossofanklefunction.Atractioninjurytothecommonperonealnervewaslikelycausedbystraighteningtheknees.Thiscomplicationcouldhavebeenavoidedbypositioningofthekneesinaflexedpositionaftersurgeryandthengraduallystraighteningthekneesbackout.Fortunately,thepatientfullyrecovered3monthsaftersurgery.内侧或外侧髌旁入路可用于外翻膝关节畸形的全膝关节置换术。髌骨外侧切口通常用于轻度至中度膝外翻畸形，以简单地松解外侧结构。考虑到本病例中髌骨的位置，外侧髌旁入路不适合获得足够的膝关节暴露;因此，我们采用内侧髌旁入路。腓神经损伤是TKA的常见并发症。在TKA矫正外翻膝关节畸形时，腓神经损伤是常见的，发生率为2%~3%[16-19]。应注意神经紧张，必要时截骨可切除腓骨头缓解神经紧张。术后，膝关节屈曲10°3-4天，以防止腓神经拉伸，并允许主动和被动活动范围（10°至70°范围）锻炼[20]。在本病例中，基于术前对手术方法的评估，我们认为腓神经不会被横断，因此我们在手术中没有暴露腓神经。然而，术后患者无法踝关节背屈。牵引损伤腓总神经可导致踝关节功能丧失。牵拉伤腓骨总神经可能是伸直膝盖引起的。这种并发症可以通过手术后将膝关节置于弯曲位置，然后逐渐将膝关节拉直来避免。幸运的是，患者在手术后3个月完全康复。Patellardislocationorsubluxationisacommonfindinginvalgusknees.Patellardislocationassociatedwithcongenitaldisordersappearstobeclassifiableintothefollowing3types:conditionsduetosofttissuelaxityandincreasedjointlaxity;conditionsduetopatellarhypoplasiaandskeletaldysplasiaofthefemurandtibia;andconditionsduetosofttissuefibrosisandcontracture.[21]Anabnormalpatellartrajectoryinthemild-to-moderatevalguskneecanbecorrectedafterkneearthroplasty.[22]Inseverevalgusconditions,thelateralpatellarretinaculum,popliteustendon,andthelateralportionofthegastrocnemiusmayrequiredetachmenttorestoretheanatomicalaxisofthelimb.Ananteromedialtibialtubercletransfermaybeperformedtocorrectpatellardislocation.Inthepresentcase,wecorrectedthesevereabnormalpatellartrajectoryandtibialinternalrotationbyreleasingthepatellarlateralsurface,vastuslateralis,andtheintramusculargapoftherectusfemoris.AZ-shapedreleaseofthebicepsfemoriswasalsoperformed.Sincethepatellartrajectorywasstillnotcompletelycorrected,wesubsequentlyreleasedthelateralcollateralligamentbycreatingmultipleneedlepunctures,incisingthevastuslateralis,andextendingitbymalposed-suturetocompletelycorrectthepatellatrajectory.髌骨脱位或半脱位是外翻膝的常见表现。与先天性疾病相关的髌骨脱位似乎可分为以下3种类型:由于软组织松弛和关节松弛增加引起的情况;髌骨发育不全，股骨和胫骨骨骼发育不良;以及软组织纤维化和挛缩引起的疾病[21]。轻度至中度外翻膝关节的异常髌骨轨迹可以在膝关节置换术后得到纠正[22]。在严重外翻的情况下，髌骨外侧支持带、腘肌肌腱和腓肠肌外侧部分可能需要脱离以恢复肢体的解剖轴。胫骨前内侧结节转移可用于矫正髌骨脱位。在本病例中，我们通过松解髌骨外侧面、股外侧肌和股直肌肌内间隙来纠正严重的异常髌骨轨迹和胫骨内旋。同时进行股二头肌Z形松解术。由于髌骨轨迹仍未完全矫正，我们随后通过多次穿刺从而松解外侧副韧带，切开股外侧肌，并通过错位缝合延长，以完全矫正髌骨轨迹。Insummary,inthisrarecase,wesuccessfullyperformedTKAusingarotatinghingekneeinstrumentforthetreatmentofavalgusdeformityangle>90°associatedwithseverebonydefectsinthefemurandtibia.Thepatellardislocationwascorrectedwithouttheuseofanteromedialtibialtubercletransfer.Postoperatively,thepatientexperiencedbilaterallossofankledorsiflexionduetoatractioninjurytothecommonperonealnerve,which,however,wascompletelyrecoveredin3months.Intraoperativeexplorationofthecommonperonealnerveandpostoperativeflexedpositioningofthekneejointscouldhelppreventnerveinjuries.However,sincethehingeprosthesiswashighlyrestricted,thelifetimeoftheprosthesisisacauseofconcern.Westillneedtoconductlong-termfollow-upsofthepatient.总之，在这个罕见的病例中，我们成功地使用旋转铰链膝关节器械进行了TKA，治疗了角度>90°的外翻畸形，并伴有股骨和胫骨的严重骨缺损。髌骨脱位不采用胫骨前内侧结节转移。术后，由于腓总神经牵拉损伤，患者双侧踝关节背屈丧失，但在3个月内完全恢复。术中探查腓总神经和术后膝关节屈曲定位有助于预防神经损伤。然而，由于铰链假体受到高度限制，假体的使用寿命是一个值得关注的问题。我们还需要对患者进行长期随访。

膝关节冠状面对线CPAK分类系统_不是所有的膝关节、全膝关节置换都是一样的（2024）Notallkneesarethesame MacDessiSJ,vandeGraafVA,WoodJA,Griffiths-JonesW,BellemansJ,ChenDB.Notallkneesarethesame[J].BoneJointJ,2024,106-B(6):525-531. 转载文章的原链接1：https://pubmed-ncbi-nlm-nih-gov-443.vpnm.ccmu.edu.cn/38821506/ 转载文章的原链接2：https://boneandjoint.org.uk/Article/10.1302/0301-620X.106B6.BJJ-2023-1292.R1 AbstractTheaimofmechanicalalignmentintotalkneearthroplastyistoalignallkneesintoafixedneutralposition,eventhoughnotallkneesarethesame.Asaresult,mechanicalalignmentoftenaltersapatient’sconstitutionalalignmentandjointlineobliquity,resultinginsoft-tissueimbalance.ThisannotationprovidesanoverviewofhowtheCoronalPlaneAlignmentoftheKnee(CPAK)classificationcanbeusedtopredictimbalancewithmechanicalalignment,andthenofferspracticalguidanceforbonebalancing,minimizingtheneedforsoft-tissuereleases.全膝关节置换术中的机械对线的目的是将所有膝关节对线到一个固定的中立位置，尽管并非所有膝关节都相同。因此，机械对线通常会改变患者的固有对线和关节线倾斜度，导致软组织失衡。本文概述了如何使用“膝关节冠状面对线（CPAK）”分类来预测机械对线引起的失衡，并提供了实用的指导，以平衡骨骼，减少对软组织释放的需要。 IntroductionIrrespectiveofthealignmentstrategyusedwhenundertakingtotalkneearthroplasty(TKA),surgeonsmustcontendwiththefactthatnotallkneesarethesame.InmechanicallyalignedTKA,balancingisusuallyperformedfollowingcompletionofthebonycutsandassessmentofthelaxityofthesoft-tissues.1Thelong-standingapproachforachievingbalanced“gaps”hasbeenbyreleasingorlengtheningligamentousandcapsularstructures,therebyalteringtheirinherentphysiologicalfunction.1,2Withagreateracceptancethatligamentsdonotcontract,3andthatimbalanceresultsfromsurgicalalterationstothepatient’sconstitutionalalignment,4amorenuancedapproachwith“bonebalancing”hasbeensuggested.5Bonebalancingmodifiesthealignmentbybiasingbonyresectionstowardsamoreconstitutionalorientation,therebymaintainingtheirfunctionandreducingthenecessityforsoft-tissuereleases.BonebalancingusinganinitialmechanicalalignmentplanrepresentsoneendofthespectrumofTKAalignmentstrategies,withunrestrictedkinematicalignmentattheother.6-10Subtlechangesofalignmentupto3°fromaneutralmechanicalaxisareoftenenoughtoimproveimbalance,andstillconsideredsafeforsurgeonswhowanttomaintainalignmentwithinthismoretraditionalwindow.11,12Restoringtheknee’sconstitutionalalignmentismorelikelytoachievesoft-tissuebalancecomparedwithusingmechanicalalignmentforallpatients.13,14TheCoronalPlaneAlignmentoftheKnee(CPAK)classificationisawidelyadoptedandpragmaticsystemthatoffersaframeworktounderstandtherelationshipbetweenthenativelowerlimbalignmentandjointlineobliquity(JLO)tothesoft-tissuebalance.14CPAKdefinesninekneephenotypesbasedonconstitutionalalignmentoftheknee,incorporatingthearithmetichip-knee-ankleangle(aHKA)andthejointlineobliquity.Inthisinstructionalreview,weusetheCPAKclassificationtounderstandwhynotallkneesarethesameintermsofimbalancewhenperformingmechanicallyalignedTKA.EachCPAKtypewillbeintroducedbasedonitsprimaryradiologicalandmorphologicalcharacteristics.AlterationstoconstitutionalalignmentthatresultwhenperformingmechanicallyalignedTKAwillbepresentedforeachCPAKtype,alongwiththeanticipatedchallengeswithbalance.Formostsurgeonswhousemechanicalalignment,andforthosewhohavenowadoptedanindividualizedapproach,understandingtheseconceptsisimportantforappreciatingwhyalignmentmatters. RadiologicalassessmentPreoperativelonglegimagingthatallowsforassessmentofthemechanicalaxisisobtainedusingplainradiographswithdigitalstitching,biplanarimagingorwhole-legCTimaging.Thelateraldistalfemoralangle(LDFA)ismeasuredasthelateralanglesubtendedbythemechanicalaxisofthefemurandthearticularlinetangentialtothedistalfemoralarticularsurface.Themedialproximaltibialangle(MPTA)ismeasuredasthemedialanglesubtendedbythemechanicalaxisofthetibiaandthearticularlinetangentialtotheproximaltibialarticularsurface(Figure1).Apartfromhighlightinglossofjointspace,shortradiographsofthekneeareofnovalueintheassessmentofconstitutionalalignment,andthereforeoftheindividual’skneephenotype.15,16  Fig.1Longlegstandingradiographsshowingthemechanicalaxesofthefemurandtibia.Therightkneeshowsmeasurementofconstitutionalalignmentinanarthritickneeusingthearithmetichip-knee-ankleangle(aHKA)algorithm.Theleftnormalkneeshowsmeasurementofthethemechanicalhip-knee-ankleangle(mHKA).LDFA,lateraldistalfemoralangle;MA,mechanicalaxis;MPTA,medialproximaltibialangle.  TheconstitutionalcoronalalignmentiscalculatedusingtheequationaHKA=MPTA–LDFA,andtheconstitutionaljointlineobliquity(JLO)usingtheequationJLO=MPTA+LDFA.TheboundariesforconstitutionalalignmentofthelowerlimbusingtheaHKAarevarus<-2°,neutral-2°to+2°inclusive,andvalgus>2°.TheboundariesforconstitutionalJLOareapexdistal<177°,neutral177°to183°,andapexproximal>183°.TheCPAKtypeisthendeterminedbasedontheseboundaries(Figure2).  Fig.2TheCoronalPlaneAlignmentoftheKnee(CPAK)classificationwithboundaries.aHKA,arithmetichip-knee-ankle;JLO,jointlineobliquity.  DatafrompreviousstudiessupportthedescriptionsofeachCPAKtypediscussedhere.Alignmentcharacteristicsarederivedfromasampleof500kneesin250healthyadults,agedbetween20and27years(SupplementaryTablei);13soft-tissuelaxitydataarederivedfromasampleof137kneescomparingbalancebetweendifferentalignmentstrategies(SupplementaryTableii);17andloadsensordataarederivedfromasampleof138kneescomparingcompartmentalloadsbetweenalignmentstrategies(SupplementaryTableiii).4Inthisannotation,onlyCPAKTypesItoVIarediscussed,asmanyauthorshaveshownthatTypesVIItoIXarerareinthegeneralpopulation.14,18-23FortheLDFAandMPTA,wecharacterizeorientationas“neutral”if≤1°from90°;“mild”if>1°and≤2°from90°;“moderate”if>2°and≤4°from90°;and“significant”if>4°from90°.DescriptiveradiologicalmeasurementsandschematicphenotypictraitsarepresentedforeachCPAKtypeandforchangestoJLO.Alterationsinconstitutionalalignment,nativefemoraljointlineanatomy,lateralfemoralcolumnlength,andtheirsequelaearesummarizedinTableI.  TableI.TheimplicationsofmechanicalalignmentbasedonCoronalPlaneAlignmentoftheKneetype.CPAK,CoronalPlaneAlignmentoftheKnee;MA,mechanicalalignment;N/A,notapplicable.  CPAKTypeIThekneesin133ofthesampleofhealthyindividuals(26.6%)wereCPAKTypeI.ThisisthemostprevalentphenotypeinAsianandIndianpatientsundergoingTKA,andisthemostcommonvarusphenotypeglobally.18,19,23Thistypeischaracterizedbysignificantproximaltibialvarusandmilddistalfemoralvalgus,resultinginavarusaHKAandanapexdistalJLO.TheimplicationsformechanicalalignmentareshowninFigure3a.MehanicalalignmentwithCPAKTypeIkneesresultsinconsiderabletightnessoftheMCLduetotheshiftinaHKAfromvarustoneutral.Asthemagnitudeofchangeincreases,sodoesthelikelihoodoflateralcondylarlift-off,asignalofmajorimbalance.TheMCListightinbothextensionandflexion.Commonly,surgeonspartiallyorcompletelyreleasetheMCLinanattempttoachievebalance,butsecondaryincompetenceoftheMCLmayresultfromreleasingthiscriticalstructure.Alterationofconstitutionalvarustoneutralwillincreasethelengthoftheleg,andincreasetheneedforathickerpolyethyleneinserttocompensatefortheartificialincreaseinmedialgapheight.24AstheprimarycharacteristicofTypeIistibialvarus,avarustibialrecutwithmechanicalalignmentmayberequiredtoachievebalanceinbothextensionandflexion.  Fig.3Illustrationofsoft-tissueimbalanceinCoronalPlaneAlignmentoftheKnee(CPAK)TypesItoVI,showinghowmechanicalalignment(MA)altersconstitutionalalignmentandjointlineobliquity.a)MAwithCPAKTypeI.Theredwedgehighlightssignificanttibialvarus,andtheredarrowindicateselevationofthemedialjointline.b)MAwithCPAKTypeII.Thegreenwedgeshighlightmoderatefemoralvalgusandmoderatetibialvarus.Theredarrowindicateselevationofthemedialjointline,andtheorangearrowindicatesdistalizationofthelateralfemoralcolumn.c)MAwithCPAKTypeIII.Theredwedgeshighlightssignificantfemoralvalgus,andtheorangearrowindicatesdistalizationofthelateralfemoralcolumn.d)MAwithCPAKTypeIV.Thegreenwedgeindicatesmoderatetibialvarus.Theredarrowhighlightselevationofthemedialjointline.e)MAwithCPAKTypeV.f)MAwithCPAKTypeVI.Thegreenwedgehighlightsmoderatefemoralvalgusandtheorangearrowindicatesdistalizationofthelateralfemoralcolumn.aHKA,arithmetichip-knee-ankleangle;JLO,jointlineobliquity.  CPAKTypeIIThekneesof205ofthehealthyindividuals(41.0%)wereCPAKTypeII.Thisisthemostcommonkneephenotypeglobally.14,22Thistypeischaracterizedbymoderateproximaltibialvarusandmoderatedistalfemoralvalgus,resultinginaneutralaHKAandanapexdistalJLO.TheimplicationsformechanicalalignmentareshowninFigure3b.MechanicallyalignedTKAspecificallyaddressesCPAKTypeIIphenotypiccharacteristics.Asneutralconstitutionalalignmentismaintained,soft-tissuebalanceinextensionisusuallynotaltered.Furthermore,byapplyingexternalrotationtothefemoralcomponent,imbalanceinflexionisunlikely.The“anatomicalalignment”methodattemptedtoreplicateTypeIIbyrecreatinganapexdistalJLO,25butimprecisecuttingguidesresultedinthistechniquebeingabandoned.ThefollowingkinematicalterationsrequireconsiderationinCPAKTypeII.Thenativefemoraljointlineisraisedmediallythroughoutthearcofmotion,apotentialcauseofmid-flexioninstability.26Thelateralfemoralcolumnislengthened(distalized)inextensionandflexion.Ithasbeensuggestedthatthismayleadtoincreasedpatellofemoralretinaculartightnessinflexionbylateraldistalfemoralprostheticoverstuffing,27particularlyinkneeswithveryobliquejointlinessuchasthoseof≤170°.Theneedforsoft-tissuebalancingwithCPAKTypeIIisminimal. CPAKTypeIIIThekneesof47ofthehealthyindividuals(9.4%)wereCPAKTypeIII.Thistypeisthemostcommonvalgusphenotypeandischaracterizedbyconsiderabledistalfemoralvalgusandmildproximaltibialvarus,resultinginavalgusaHKAandapexdistalJLO.TheimplicationsformechanicalalignmentareshowninFigure3c.Imbalancewithmechanicalalignmentoccursinextensionandtoalesserextentinflexion,astheaHKAisshiftedfromvalgustoneutral.Thedegreeoflateraltightnessisdependentontwovariables:themagnitudeofaHKArelativetothechangeprescribedbymechanicalalignment;andthevariabilityinconstitutionallaxityofthelateralsiderelativetomediallaxity.Inmanyknees,increasedconstitutionallaterallaxity,whichisfurtherincreasedafterresectionofthecruciateligaments,28–30cancompensateforthisshiftinaHKAandreducetheneedforlateralbalancing.However,inourexperience,whenpatientshaveanaHKAof≥5°,soft-tissueimbalanceinevitablyresults.AstheprimarycharacteristicofCPAKTypeIIIissignificantfemoralvalgus,adistalfemoralvalgusrecutmayberequiredtoachievebalanceinextension. CPAKTypeIVThekneesof21ofthehealthyindividuals(4.2%)wereCPAKTypeIV,whichisararervarusphenotype,characterizedbymoderateproximaltibialvarusandmilddistalfemoralvarus,resultinginavarusaHKAandneutralJLO.TheimplicationsformechanicalalignmentareshowninFigure3d.AswithTypeI,therewillbeMCLtightnessinCPAKTypeIVwithmechanicallyalignedTKA.However,thistightnessismoreprominentinextensionthanflexion.14AsthemajoranatomicalcharacteristicinCPAKTypeIVistibialvarus,avarustibialrecutmayberequiredtorestorebalanceinbothextensionandflexion,althoughanadditionalvarusfemoralrecutcanbeconsidered. CPAKTypeVThekneesof77ofthehealthyindividuals(15.4%)wereCPAKTypeV,whichisthetargetinmechanicallyalignedTKA.Thistypeischaracterizedbyneutraldistalfemoralandneutralproximaltibialanatomy,resultinginaneutralaHKAandneutralJLO.TheimplicationsformechanicalalignmentareshowninFigure3e.NobalancinginterventionsareusuallynecessaryforCPAKTypeVwithmechanicalalignment.However,unlikeCPAKTypeIIknees,thetibialjointlineisnotchanged,andsurgeonsshouldevaluatewhethertheroutine3°externalrotationofthefemoralcomponentisneeded. CPAKTypeVIThekneesof16ofthehealthyindividuals(3.2%)wereCPAKTypeVI.Thistypemakesupapproximatelyone-quarterofallvalgusknees,andischaracterizedbymoderatedistalfemoralvalgusandmildproximaltibialvalgus,resultinginavalgusaHKAandneutralJLO.TheimplicationsformechanicalalignmentareshowninFigure3f.ComparedwithCPAKTypeIII,constitutionalvalgusiscontributedtobyfemoralvalgusand,toalesserextent,tibialvalgus.Thisresultsinaneutraljointlineobliquity.Soft-tissueimbalanceismostpronouncedinextension.14AsthemaincharacteristicofTypeVIisfemoralvalgus,avalgusfemoralrecutmayberequiredifthereismarkedlateraltightnessinextension.Ifthereremainssomeimbalance,orwhenfemoralrecutsarepreferablyavoided,areleaseoftheposterolateralcapsular(arcuate)complex,withorwithouttheposteriorbandoftheiliotibialband,maybeconsidered.31 DiscussionThisinstructionalannotationpresentsamethod,basedonconstitutionalalignment,forunderstandingandpredictingthesoft-tissueimbalancethatoftenresultswhenundertakingmechanicallyalignedTKA.Itprovidesclear,alignment-drivenreasoningbasedondeviationstocommonCPAKphenotypes.Imbalancesaremostprofoundinconstitutionalvarusknees,TypesIandIV.However,constitutionalvalgusknees,TypesIIIandVI,alsopresentintraoperativechallenges.Theabilitytounderstandthelikelihoodofencounteringimbalancepriorto,andduring,surgeryisempowering.Theconceptscanalsobeusedbythosewhouseagap-balancingapproachwithconventionalcuttingguides,astheystreamlinetheworkflowofbothtibial-andfemoral-basedtechniques.Mostimportantly,notallkneesarethesame,andtherewillbemuchvariationbetweenindividuals,evenwithineachCPAKtype.Thus,onepatientwithaTypeIIkneemayhaveaLDFAof88°andMPTAof88°,anothermayhaveaLDFAof84°andMPTAof83°.Treatingbothkneeswiththesamemechanicallyalignedresectionsislikelytobringaboutdifferentkinematicresults.Or,whenapatientwithaTypeIkneewithanaHKAof-3°mayonlyrequirea2°varusrecutinordertoobtainabalancedknee,another,alsowithaTypeIknee,butanaHKAof-7°,isunlikelytobebalancedwithasmallvaruscorrectionfrommechanicalalignment.Furthermore,CPAKisaclassificationsystemtodescribephenotypesandisnotgranularenoughtoprovideacomprehensivebreakdownofhowbalancingshouldbeexecutedwhenperformingmechanicallyalignedTKA.Furthermore,itisnotonlytheconstitutionalalignmentbutalsotheconstitutionallaxitythatdeterminesthebalanceofaTKA.Nativelaxitiesarehighlyvariableinboththecoronal(extensionandflexion)andsagittalplanes.32-35Thus,akneecanhaveitsconstitutionalalignmentperfectlyrestored,asinunrestrictedkinematicalignment,butstillhaveunbalancedgaps.17,36TargetingbalancedcoronalandsagittalgapsremainsamajorgoalinTKAandisthecornerstoneofthefunctionalalignmenttechnique.17,36,37However,theoptimalbalance,includingwhetherrectangularortrapezoidalconstitutionalgapsshouldbethenewtarget,remainspoorlydefined.Surgeonsmustcontinuetousetheirclinicalacumentoassesseachkneeonitsmerits,applyingtheknowledgeofoutcomesdeterminedbyphenotype,tooptimizealignmentandbalance.Conventionalcuttingguideswithmechanicalalignmenthavealsobeenreportedtohaveprecisionerrorsof>3°in30%ofcases,38withhalfofthosecasespotentiallydeviatingintomorethan3°varus(15%)andhalfintomorethan3°valgus(another15%).Forexample,ifasurgeonaimingformechanicalalignmentusingconventionalinstrumentsunintentionallyalterstheHKAofakneethathas5°ofconstitutionalvarusto≥4°ofmechanicalvalgus,thiscouldresultinaprofoundchangeinalignmentof9°,thetypeofsituationthatcouldoccurin1in6(15%)ofmechanicallyalignedTKAsundertakenusingconventionalcuttingguides.SeveretightnessoftheMCLwillresultinlateralcondylarlift-off.TheonlywaytocorrectthisimbalanceistoreleasetheMCLfromitstibialinsertion.Thiswillresultinanincreaseinbothmedialflexionandextensiongaps,thesubsequentneedforathickerpolyethyleneinsert,andaneteffectoflengtheningthelimb.24CorrectiontowardsamorevarusphenotypeispreferredtoacompletereleaseoftheMCL.Theinherentlimitationsofconventionalcuttingguidesarethattheydonotallowquantificationorvalidationoftheanglesofresectionorthefinalalignmentofthelimb.Aswegraduallyshifttowardsmorepersonalizedoperationsforourpatients,itishopedthatthisannotationwillencouragesurgeonstoconsidereachpatient’suniqueCPAKtype.This,inpart,maymaketheoutcomesofTKAmorepredictable,reducingtheneedforsoft-tissuereleaseswhileusingadjustmentsinalignmenttorestorethenativebalanceoftheknee. Takehomemessage-Inthisreview,theCoronalPlaneAlignmentoftheKnee(CPAK)classificationisusedtoenhanceourunderstandingofwhynotallkneesarethesamewhenconsideringsoft-tissueimbalanceinmechanicallyalignedtotalkneearthroplasty.-Bonebalancinginterventionsbasedonanunderstandingofeachpatient’suniqueCPAKtypecanbeusedtoavoidunnecessarysoft-tissuereleases.-Theseconceptsmaybeconsideredbysurgeonsinterestedinamoreindividualizedalignmentstrategy,insteadofafixedmechanicalalignmenttargetforallpatients.在本综述中，采用“膝关节冠状面排列（CPAK）”分类来增强我们对在机械对线全膝关节置换术中考虑软组织失衡时为何并非所有膝关节都相同的理解。基于对每位患者独特CPAK类型的理解，可以实施骨平衡干预措施，以避免不必要的软组织释放。这些概念可能对有兴趣采用更个性化对齐策略的外科医生有所帮助，而不是为所有患者设定固定的机械对线目标。

继发于发育性髋关节发育不良的股骨头坏死的Bucholz-Ogden分类系统_继发于发育性髋关节发育不良的股骨头坏死全髋关节置换的年轻成人患者的深入分析（2024）Bucholz-OgdenclassificationforosteonecrosissecondarytoDDH_Anin-depthanalysisofyoungadultswithosteonecrosissecondarytodevelopmentaldysplasiaofthehipwhounderwenttotalhiparthroplasty NayarSK,MarksA,Hashemi-NejadA,RoposchA.Anin-depthanalysisofyoungadultswithosteonecrosissecondarytodevelopmentaldysplasiaofthehipwhounderwenttotalhiparthroplasty[J].BMCMusculoskeletDisord,2024,25(1):436. 转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/38835008/ 转载文章的原链接2：https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11149231/ AbstractBackgroundPatientswithosteonecrosisofthefemoralheadsecondarytoDDHfrequentlyrequiretotalhiparthroplasty(THA),butitisnotwellunderstoodwhichfactorsnecessitatethisrequirement.WedeterminedtheincidenceofTHAinpatientswhohaveosteonecrosissecondarytoDDHandfactorsassociatedwithneedforTHA. MethodsWeincludedpatientswhoreceivedclosedoropenreductionsbetween1995and2005withsubsequentdevelopmentofosteonecrosis.WedeterminedosteonecrosisaccordingtoBucholzandOgden;osteoarthritisseverity(Kellgren-Lawrence),subluxation(Shenton’sline);neck-shaftangle;andacetabulardysplasia(centre-edgeandSharpangles).WealsorecordedthenumberofoperationsofthehipinchildhoodandreviewedcasenotesofpatientswhoreceivedTHAtodescribeclinicalfindingspriortoTHA.WeassessedtheassociationbetweenradiographicvariablesandtheneedforTHAusingunivariatelogisticregression. ResultsOf140patients(169hips),22patientsreceived24THA(14%)atameanageof21.3 ± 3.7years.AssociatedwiththeneedforTHAweregradeIIIosteonecrosis(OR4.25;95%CI1.70-10.77;p = 0.0019),gradeIVosteoarthritis(21.8;7.55–68.11;p < 0.0001)andsubluxation(8.22;2.91–29.53;p = 0.0003).AllpatientswhorequiredTHAreportedatleast2of:severepainincludingatnight,stiffness,andreducedmobility.AcetabulardysplasiaandnumberofpreviousoperationswerenotassociatedwiththeneedforTHA. ConclusionsWeidentifieda14%incidenceofTHAbyage34yearsinpatientswithosteonecrosissecondarytoDDH.GradeIIIosteonecrosis(globalinvolvementfemoralheadandneck)wasstronglyassociatedwithTHA,emphasisingtheimportancetoavoidosteonecrosiswhentreatingDDH.  Keywords:DDH,Osteonecrosis,Totalhiparthroplasty BackgroundOsteonecrosisofthefemoralheadisawell-recognisedcomplicationinthetreatmentofdevelopmentaldysplasiaofthehip(DDH),withareportedincidenceofupto73%afterclosedoropenreduction[1–5].Thesequalaefollowingosteonecrosisincludesproximalfemoralgrowthdisturbance,femoralheadcollapseandinhibitionofacetabularremodelling,allofwhichcanpredisposetoearlyonsetosteoarthritis.InpriorresearchweshowedthatyoungadultswithosteonecrosissecondarytoDDHdemonstratedminimaloverallphysicaldisabilityandanormalqualityoflife;howevertheirhipfunctionwasreducedinthepresenceofosteonecrosisgradesIIIandIVaccordingtoBucholzandOgden[6].Thispreviousstudyexcludedpatientsthathadreceivedtotalhiparthroplasty(THA).Todate,thereisnoliteratureconcerningfactorsnecessitatingTHAinpatientswithosteonecrosissecondarytoopenorclosedreductionsinDDH.WhilstmodernTHAimplantsinyoungadultshaveshownpromisingfunctionaloutcomesandrevisionrates[7,8],itisnotwithoutitsrisksandthereishighchanceofrequiringrevisioninone’slifetime.ItisthereforeimportanttounderstandtheincidenceofTHAfollowingthiscomplicationandtheriskfactorsthatnecessitateit.Thiswillhelpustobetterinformourpatientsaswellasidentifythosewhomightbeathigherrisk,whichmayinfluencesurveillanceandtreatmentoptionstoimprovehipbiomechanicsanddelayneedforTHA[9].Theaimsofthisstudyweretodescribe[1]theincidenceofTHAinpatientswithosteonecrosissecondarytoDDH[2],associationsbetweenradiographicparametersandtheneedforTHA,and[3]thecharacteristicsofpatientswhounderwentTHA. MethodsThelocalResearchEthicsCommitteeapprovedthisstudy(REC14/LO/1267).Writteninformedconsentwasobtainedfromallpatientsovertheageof16yearsandwritteninformedconsentwasobtainedfromparent/guardiansofthoseundertheageof16years.WeincludedpatientswithadiagnosisofDDHwhohadreceivedaclosedreductionoropenreductionwithorwithoutosteotomybetween1995and2005andwhosubsequentlydevelopedosteonecrosis.Allpatientsweretreatedintwotertiarycentresandwereidentifiedfromourpreviousstudy[6]withnochangeinthestudypopulation.Of140patientsincluded,29hadbilateralosteonecrosis,encompassingatotalof169hips.Ofthese,24hips(14%)proceededtoarthroplasty,whereastwopatientsreceivedbilateralTHA(Fig. 1).ThemeanageatthetimeofTHAwas21.3years(range,16–29years)(Table4inAppendix1).Anothertwopatients(1%)underwenthiparthrodesisatages9and12years.Thesepatientswerenotrepresentativeofthestudygroupandthereforeexcludedfromfurtheranalysis.Wecomparedpatient-characteristicsincludingsex,laterality,numberofprioroperationsandageatstudybetweenpatientswithandwithoutTHA.  Fig.1Flowdiagramshowingpatienteligibilityandparticipation.THA,totalhiparthroplasty  AllparticipantshadastandingAPpelvicradiographatthetimeofourpreviousstudyassessmentin2017[6].IncaseswhereTHAhadalreadybeenundertaken,theirlatestAPpelvicradiographpriortohipreplacementwasused.InonecaseradiographspriortoTHAwerenotavailable,thereforeradiographicanalysiswasonlyperformedfor23hipsintheTHAgroup.Allradiographswerecarriedoutusingastandardisedprotocolonadigitalimagingsystem(GEMedicalSystemsLtd.,Buckinghamshire,UK)(Fig. 2).GradeofosteonecrosiswasassessedaccordingtoBucholz-Ogden[10].GradeIchangesarelimitedtothefemoralheadwithhypoplasiaofthefemoralheadbutnormalossificationofthemetaphysis.InGradeII,thelateralmetaphysisisinjuredandthefemoralheadwillgrowintovalgus.ForGradeIII,theentiremetaphysisisinvolvedresultinginshorteningofthefemoralneckwithtrochantericovergrowth.AninjuryordefectalongthemedialmetaphysisispresentinGradeIVcausingvarusoftheproximalfemur(Fig. 3).一级改变仅限于股骨头发育不良，但股骨颈的骨化正常。二级改变时，外侧骨骺受伤，股骨头会外翻生长。三级改变时，整个骨骺都受到影响，导致股骨颈缩短，大转子过度生长。四级改变时，内侧骨骺出现损伤或缺陷，导致股骨近端内翻。 OsteoarthritiswasgradedaccordingtoKellgren-Lawrence[11].Acetabulardysplasiawasquantifiedbymeasuringthecentre-edgeangleofWiberg[12]andtheacetabularangleofSharp[13].Allradiographswereassessedbytwoindependentreviewersasoutlinedpreviously[6].Interraterreliabilitywasdeemedexcellentforthecentre-edgeandacetabularangles(intra-classcorrelationcoefficient = 0.86),andmoderatefortheKellgren-Lawrence(κ = 0.62)andBucholz-Ogden(κ = 0.64)grading.Consensuswasobtainedwiththeseniorauthor(AR)inthecaseofanydisagreements[6].AllpatientsthatunderwentTHAhadtheirclinicalassessmentandsurgeryunderthesamesurgeon(AHN).  Fig.2A Apelvicradiographobtained15yearsafteropenreduction,Salterinnominateosteotomyandfemoralvarusde-rotationosteotomy.ItshowsgradeIIIosteonecrosisofthelefthipina17-year-oldgirl.Thereistotalfemoralheadinvolvement,markedacetabulardysplasiaandsubluxationofthehip.ShehadapositiveTrendelenburggaitand1 cmdifferenceinleglengths.B Pelvicradiographofthesamepatient5yearspostTHA,performedatage18years  Fig.3RadiographsrepresentingGradeI,GradeII,GradeIII,andGradeIV(fromlefttoright)oftheBucholz-OgdenclassificationforosteonecrosissecondarytoDDH继发于发育性髋关节发育不良的股骨头坏死的Bucholz-Ogden分类系统  ClinicalinformationforthepatientsthatreceivedTHAwascollectedbyreviewingtheelectronicpatientrecords,specificallylookingatfactorsthatmayinfluenceneedforTHA.Thisincludedthenatureoftheirpreviousoperationsofthesamehip,co-morbidities[14],medications[15],smokingstatus[16],drugoralcoholabuse[17,18],clinicalsymptomspriortoTHAsuchaspainandwalkingability,andexaminationfindingspriortoTHA[19,20].Intwocasestheexactnatureoftheirpreviousoperationscouldnotbeidentified.WecomparedgroupsusingchisquareorFisher’sexacttestandStudent’sttestasappropriate.WeusedunivariablelogisticregressiontoexamineassociationsbetweenradiographiccharacteristicsandneedforTHA.Because‘subluxation’isaknownriskfactorforearlyhipfailure,wetestedtheeffectofosteonecrosisadjustedforsubluxationusingFirth’spenalisedlikelihoodestimates[21].WeestimatedthecumulativeoccurrenceofTHAovertimeusingKaplan-Meiersurvivalanalysis.Werepeatedtheanalysisbyrandomlyexcludingofonesideinbilateralcasestoassessnon-independenceinthesepatients,whichdidnotresultinanysignificantchangetothereportedresults[22,23].InsensitivityanalysesweaccountedforpotentiallymissedcasesofTHA(e.g.thoseperformedinotherhospitals,thusunknowntous):werepeatedtheanalysesandrandomlyselectedsubjects)intotheTHAgroupat17%,20%,22%and25%;thisdidnotchangetheestimatesofeffect.AlldatawereanalysedusingGraphPad®Prism9(GraphPadSoftware,California,USA). ResultsByage34years24THA(14%)wereobserved,twopatients(9%)underwentbilateralTHA(Fig. 4).Inonecasethesewereperformedonemonthapart,andintheothertheywereperformed28monthsapart.Onepatient(4%)hadbilateralosteonecrosiswhereonlyasinglesidewarrantedTHA.  Fig.4GraphshowingthecumulativeoccurrenceofTHA(solidline)and95%confidenceinterval(dottedline)  PatientswithTHAwereolderatthetimeofstudyassessmentby3 ± 1years(p = 0.0003);buttheyweresimilarintermsofsex(p = 0.308),laterality(p = 0.635)andnumberofprioroperations(p = 0.227)(Table 1).  Table1Groupdifferencesbasedonunivariateanalysis  FactorsassociatedwithTHAincludedosteonecrosisofgradeIII(OR4.25,95%CI1.70–10.77;p = 0.0019);osteoarthritisofgradeIV(OR21.78,95%CI7.55–68.11;p < 0.0001);andsubluxation(OR8.22,95%CI2.91–29.53,p = 0.0003)(Table 2).Alowerneck-shaftanglewasweaklyassociatedwithTHA(OR0.96,95%CI0.93–0.99;p = 0.0262),whichwaslostonsensitivityanalysisbeyondanassumptionofanyadditionalpatientsundergoingTHA.MarkersofacetabulardysplasiawerenotassociatedwithTHA.TheeffectofgradeIIIosteonecrosisremained(p = 0.0026)whentheanalysiswasadjustedforsubluxationofthehip.  Table2Radiographicresultsbasedonunivariateanalysis  OfthehipsrequiringTHA,11hips(46%)werereducedclosedand10(42%)werereducedopen.Twohips(8%)receivedproximalfemoralosteotomyonly,fourhips(17%)receivedpelvicosteotomyonlyandeighthips(33%)underwentbothproximalfemoralandpelvicosteotomy(Table 3).Therewasnoidentifiedassociationbetweenthosethatreceivedclosedversusopenreductionandgradeofosteonecrosisorosteoarthritis.  Table3Characteristicsof22patientsatthetimeofreceivingTHA  Thirteenpatients(59%)hadnoco-morbidities,fivepatients(23%)hadobesity(BMI > 30),onepatienthadhypermobility,onehadIgAnephropathyfollowingHenoch-SchönleinPurpura,onehadasthmaandonehadbilateraltalipesequinovarus.Onepatientwasasmoker(20cigarettesperday).Therewasnomentionofalcoholorillicitdruguseinanyofthesecases.AverageBMIwas25(range17to41)(Table 3).Nineteenpatients(86%)hadreportedseverepainpriortoTHA,includingnightpainin16patients(72%).Intheremainingthreepatients,twowerepredominantlytroubledbystiffnessandoneexperiencedpaininconjunctionwitha5 cmleglengthdiscrepancy.Reducedmobility,withaninabilitytowalkbeyondonemileor10 min,wasreportedin17cases(77%).ApositiveTrendelenburgtestindicatingpoorabductorfunctionwasreportedinsixcases(Table 3). DiscussionOsteonecrosis,orphysealarrest,isaseriouscomplicationinthetreatmentofDDHandoccursinupto73%ofcases[1–5].Whilstitspathogenesisisunknown,risksfactorsincludeageatindexsurgery[24],perioperativeinjurytotheproximalfemoralbloodsupply[25],andaneccentricpositionofthefemoralheadinplaster[26].Ourpreviousstudyshowedoverallhighscoresinpatient-reportedoutcomesatameanageof21years[6].However,in18patientstheirfunctionwassopoorthattheyhadreceivedTHA.Sincethen,afurtherfourpatientsinthisstudypopulationhavealsodeterioratedtothepointofneedingaTHA.Wewantedtoconductanin-depthanalysisofthese24patientsinordertodiscerncommonfeaturesresultinginTHA.14%ofourpatientsrequiredaTHAbyage34years,someofwhichwereperformedasearlyas16yearsofage.Naturally,thedominatingfeaturesnecessitatingTHAincludedsevereosteoarthritisin74%ofcases,subluxationofthehipin83%ofcasesandgradeIIIosteonecrosisin52%.GradeIIIosteonecrosisaccordingtoBucholz-Ogdenischaracterisedbycompletephysealarrestwithfemoralneckshortening(coxabreva),femoralheadflattening(coxaplana)andrelativeovergrowthofthegreatertrochanter.Itisthusregardedthemostsevereformofosteonecrosis,notonlyintermsofmorphologybutalsointermsoffunctionaloutcomes[2,27].Furthermore,sloweracetabularremodellinghaspreviouslybeenobservedindysplastichipswithgradeIIIosteonecrosis[28].TherewasnoassociationbetweengradeIVosteonecrosisandtheneedforTHA.Thismaybeconfoundedbytherelativelysmallernumberofpatientswiththisgradeofosteonecrosisinthisstudy.Incontrast,gradeIIosteonecrosis,whichischaracterisedbylateralphysealarrestandcoxavalga,hadaprotectiveeffectagainstneedforTHA.Oneexplanationforthisisthatsuchhipswouldhavebeenmorelikelytoreceivevarusosteotomiesoftheproximalfemurleadingtoimprovedfemoralheadcoverageandjointcongruency.This,inturn,wouldoptimisethebiomechanicswithreducedstressloadingandinstability[28].AbrokenShenton’slinehasbeendemonstratedtobeanaccurateradiographicpredictoroffemoralheadsubluxation[29].Thishasbeenlinkedtoincreasedacetabularlateraledgeloadingandsubsequentdevelopmentofosteoarthritis[30],henceresultinginincreasedneedforTHA.Fromourdataset,78%ofallpatientswithgradeIIIorIVosteoarthritisdisplayedasubluxatedhip.AlowerneckshaftanglewasweaklyassociatedwithneedforTHA.However,thisassociationwaslostduringsensitivityanalysis.Coxavarainthecontextofosteonecrosisisfrequentlyassociatedwithadditionalmorphologicalchangesincludingcoxaplana,trochantericovergrowthandleglengthdiscrepancy,allofwhichcancontributetodevelopmentofosteoarthritis,ratherthanlowerNSAbeinganindependentriskfactorinitself[31].Notably,theassociationbetweenacetabulardysplasiaandtheneedforTHAwasofborderlinestatisticalsignificanceinthisstudy.Roposchetal.[32]establishedthatinhipswithDDH,osteonecrosisreducedacetabularremodellingtoadegreethatwaslinkedwithanincreasedriskforosteoarthritis.Thesefactorscombinedresultindevelopmentofosteoarthritis.Severeosteoarthritissubsequentlyresultsinincreasingpainandstiffness,withresultantreductioninmobility,function,andoverallqualityoflife.ValiditystudieshavedemonstratedaclearrelationshipbetweenradiographicKellgren-Lawrencescore,clinicalsymptomsofhiposteoarthritisincludingpainandreducedrangeofmotion,andneedforTHA[33,34].Clinically,patientsinourcohortrequiredTHAduetosevereanddebilitatinghippainincludingatnight,stiffness,andsignificantreductioninmobility(tolessthan1mileor10 min).Osteonecrosiscanresultinovergrowthofthegreatertrochanterwithresultantshorteningoftheabductorleverarmandhenceabductormuscleweakness.WhilstsomepatientsinthisgrouphadapositiveTrendelenburgtesttoindicatepoorabductorfunction,thiswasnotaclearthemeforallpatientsthatunderwentTHA.Hence,poorabductorfunctiondoesnotappeartobeanindependentfactorassociatedwithneedforTHA.Therearelimitationstothisstudy.Notably,comparativedatawasonlyavailableforradiographicinformationandnumberofpreviousoperations,andcouldnotbeobtainedforclinicalparametersduetotheretrospectivenatureofthisstudy.Radiographicmarkerswerelimitedtoasinglesnapshotintime.TheBucholz-OgdenclassificationofosteonecrosissecondarytoDDHhasbeenreportedtohavevariableinterraterreliability,particularlywhendistinguishingbetweengradesIandII,thereforeresultsshouldbeinterpretedwithcaution[35].Furthermore,thestudydesignonlyallowsforassociationratherthantruecausalrelationship.Biasfrombilateralcasesandpotentialmissedcaseswasaccountedforwithnosignificantchangeinthereportedresults.WhilstthisstudyprovidessomeinterestinginsightsintothefactorsassociatedwithincreasedneedforTHA,furtherprospectivedatacollectionovertimeiswarrantedtobetterexploretheseassociations. ConclusionsThisstudyidentifieda14%incidenceofTHAbyage34yearsinpatientswithosteonecrosissecondarytoDDHfollowingpreviousclosedoropenreduction.AssociatedfactorsincludeBucholz-OgdengradeIIIosteonecrosis,Kellgren-LawrencegradeIVosteoarthritisandsubluxationofthehip.HipsatriskofTHAshouldbereviewedmorecloselyandifsymptomatic,discussedwithayoungadulthipunitwithrespecttowhetherfurtherhippreservationsurgeryshouldbeundertakensoasnottocompromisetheresultsofaTHA.Furthermore,thesefindingsemphasisetheimportancetoavoidosteonecrosiswhentreatingDDH.

髋关节的关节囊盂唇复合体:解剖、疾病、术前与术后MRI特征(2024)HipCapsulolabralComplex:Anatomy,Disease,MRIFeatures,andPostoperativeAppearance FloresDV,FosterR,SampaioML,RakhraKS.HipCapsulolabralComplex:Anatomy,Disease,MRIFeatures,andPostoperativeAppearance[J].Radiographics,2024,44(2):e230144. 转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/38300815/ 转载文章的原链接2：https://pubs.rsna.org/doi/10.1148/rg.230144?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed AbstractThehipisauniquelyconstrainedjointwithcriticalstaticstabilityprovidedbythelabrum,capsuleandcapsularligaments,andligamentumteres.Thelabrumisafibrocartilaginousstructurealongtheacetabularrimthatencirclesmostofthefemoralhead.Labraltearsarelocalizedbasedontheclock-facemethod,whichdeterminestheextentofthetearwhileprovidingconsistentterminologyforreporting.Normallabralvariantscanmimiclabraldiseaseandcanbedifferentiatedbyassessmentofthicknessorwidth,shape,borders,location,andassociatedabnormalities.TheLageandCzernyclassificationsystemsarecurrentlythemostwell-knownarthroscopicandimagingsystems,respectively.Femoroacetabularimpingementisariskfactorfordevelopmentoflabraltearsandisclassifiedaccordingtobonedysmorphismsofthefemur("cam")oracetabulum("pincer")orcombinationsofboth(mixed).Thecapsuleconsistsoflongitudinalfibersreinforcedbyligaments(iliofemoral,pubofemoral,ischiofemoral)andcircularfibers.Capsularinjuriesoccursecondarytohipdislocationoriatrogenicallyaftercapsulotomy.Capsularrepairimproveshipstabilityattheexpenseofcapsularovertighteningandinadvertentchondralinjury.Theligamentumteresissituatedbetweentheacetabularnotchandthefoveaofthefemoralhead.Initiallyconsideredtobeinconsequential,recentstudieshaverecognizeditsroleinhiprotationalstability.Existingclassificationsystemsofligamentumterestearsaccountforinjurymechanism,arthroscopicfindings,andtreatmentoptions.Injuriestothelabrum,capsule,andligamentumteresareimplicatedinsymptomsofhipinstability.Theauthorsdiscussthelabrum,capsule,andligamentumteres,highlightingtheiranatomy,pathologicconditions,MRIfeatures,andpostoperativeappearance.  图1  Abbreviations:FAI=femoroacetabularimpingement,ILFL=iliofemoralligament,ISFL=ischiofemoralligament,MRA=MRarthrography,PDFS=protondensity–weightedfat-suppressed,PFL=pubofemoralligament,T1FS=T1-weightedfat-suppressed TEACHINGPOINTS„  Byconvention,labraltearsarelocalizedbasedontheclock-facemethod,where3o’clockisanterior(demarcatingtheanteriorsuperiorandanteriorinferiorquadrants),6o’clockisthetransverseligament,and12o’clockisthesuperiorapexoftheacetabulum.Thiswasshowntobeanaccuratemethodthatmatchesthearthroscopist’slocalizationandimpressionoftheextentoflabraltears,therebyprovidingastandardizedmethodofreporting.„  Incontradistinctiontolabraltears,whichareirregularandextendintothelabralsubstance,themarginsofthelabrumattheinterfacewithasulcuswillbesmooth.Otherfeaturesthatfavorasulcusoverateararelessthanone-halflabralwidthfluidsignalintensitybetweenthebaseofthelabrumandtheacetabularrim;linearshape;absenceofregionalparalabral,cartilage,orosseousabnormalities;andposteriorinferiorquadrantlocation.„  Incontrasttothenativelabrum,increasedsignalintensityintheoperatedlabrumthatsurfacesisnotnecessarilyaretearandmayrepresentgranulationtissueorahealedtear.Increasedfluid-orgadolinium-intensitysignalwithinthelabrumthatsurfaces,extensionoflabralabnormalitybeyondthesutureanchorzoneorbeyondthemarginsoftheoriginaltear,paralabralcyst,andlabraldistortionaresignsofaretear.„  Capsularlesionsintheabsenceoftraumatichipdislocationmayberelatedtoopenorarthroscopiccapsulotomyorcapsulardehiscence.Intheabsenceofcapsularrepair,postoperativechangestotheadjacentstructures,capsularirregularity,edema,orafrankdefectmayindicatethesiteofarthroscopytrocarplacement.Capsulardehiscenceisapossiblecomplicationofcapsularrepair.ItisappreciatedatMRIasadisruptedordiscontinuouspseudocapsule,oftencharacterizedbyafluid-filledgapwithorwithoutassociatedpseudocapsularthickeningandhyperintensity.„  Iatrogenicinstabilityisararepostarthroscopycomplication.Osseousriskfactorsincludeexcessiveboneremovalduringacetabularrimresectionorfemoralosteoplasty.Largecapsulotomieswithoutcapsularrepairandnonhealingcapsulardefectsfrompreviousarthroscopyareexamplesofsoft-tissueriskfactors. IntroductionThehipisaball-and-socketjointconsistingofthecuplikeacetabulum,whichreceivesthesphericalfemoralhead.Itisauniquelyconstrainedjoint,inlargepartduetolarge-volumecoverageofthefemoralheadbytheacetabulum.Staticstabilityisfurtherprovidedbythreeimportantsoft-tissuestructures:thelabrum,capsuleandcapsuloligamentouscomplex,andligamentumteres(Fig1).  Figure1.Graphicillustrationdepictsthecapsulolabralcomplexofthehip.  Thelabrumandcapsulearecriticalcomponentsofthejoint’sstrongsuctionmechanism,maintainingtheintra-articularhydrostaticpressurenecessarytocontainthefluidwithinthecentralcompartment(1).Thecapsuleandcapsularligamentsallowafullrangeofmotionbutrestrictmovementsthatpredisposetosubluxationanddislocation.Theligamentumteresisasecondarystabilizerofthehip,supplementingthecapsularligamentsbyactingasa“sling”topreventsubluxationofthefemoralheadattheextremesofmotion.Thesize,variableform,andorientationofthesestabilizers,alongwithcloseappositionofthejoint’sarticularsurfaces,makeimagingevaluationchallenging.Furthermore,theadventofhiparthroscopyhasincreasedrecognitionofnumerouspathologicconditionsaffectingthesestructures,requiringcarefulscrutinybytheradiologist.Thisarticlediscussesthelabrum,capsule,andligamentumteres,emphasizingtheiranatomy,pathologicconditions,MRIfeatures,andpostoperativeappearance.Hipinstability,asourceofmuchcontroversyanddebate,isalsodiscussed,highlightingtheterminologyandclassification. ImagingConsiderationsConventionalradiographyremainsthefirstlineofimagingforinvestigationofallhipdisorders.Inthecontextofcapsulolabralstructures,itallowsevaluationofosseousdysmorphismsthatmaypredisposetolabraltearsorhipinstability,including“cam”and“pincer”femoroacetabularimpingement(FAI),hipdysplasia,andosteoarthritis.USisusefulinscreeningfortendondisease,muscletears,jointeffusion,andperiarticularfluidcollections.CT,withitscross-sectionalcapabilityandstrongdepictionofosseousmorphology,allowscharacterizationofhipdysplasiaandcamorpincerdeformitiesinmultiplanarandthree-dimensionalforms(FigS1).Inpatientswhoarecandidatesforjoint-preservationsurgery,italsoenablescalculationofimportantmetricssuchasacetabularandfemoralversion(2).MRIremainstheimagingtoolofchoicefordirectevaluationofthelabrum,capsularligaments,andligamentumteres(3).Optimizedprotocolsincludeadedicatedsurfacecoil,targetedfieldofview,thinsectionthickness,andhighin-planeresolutiontodepicttheanatomyanddiseaseofthesesmallstructures.Theadditionofthree-dimensionalacquisitionsthatuseisotropicvoxels(voxelswiththesamedimensionsinthex,y,andzplanes)enablesimagestobereconstructedinanyplane(4).Radialreconstructions,specifically,generateimagesorientedperpendiculartothecurvatureofthejoint,henceprovidingtruecrosssectionsofallquadrantsofthejoint.Theyareunhinderedbypartial-volumeeffects,optimizingdepictionofcartilageandthelabrum,whichisparticularlyimportantininvestigationofFAI(5).VisualizationofcapsulolabralstructuresisfurtherimprovedbycombiningMRIwithintra-articularcontrastmaterialorMRarthrography(MRA).Comparedwiththestandardofreferenceofarthroscopy,MRAexhibitsspecificity,sensitivity,andaccuracyof100%,92%–100%,and93%–96%,respectively,fordiagnosinglabraltears(6–8).Recentstudieshavedemonstratedthatconventionalornonarthrographic3-TMRImaybeadequateforevaluationofthelabrum(9–11).Astudyof38patientswithsuspectedFAIfoundaspecificityof50%butsensitivity,accuracy,positivepredictivevalue,andnegativepredictivevalueof98%–100%fornonarthrographicMRIwitharthroscopyasastandardofreference(9).Anotherinvestigationof68patientswithFAIalsofoundthatconventional3-TMRIisequivalentto1.5-TMRAfordetectinglabraltears(12).Arecentmeta-analysisfoundthatthesensitivityof3-TMRIwasclosetothatofMRA(pooledsensitivityof80%vs89%)anditsspecificitywashigherthanthatofMRA(pooledspecificityof77%vs69%)(11).Atourinstitution,conventional3-TMRIhasreplacedMRAastheworkhorseforinitialevaluationofhipinternalderangement.WereserveMRAforevaluatingapostoperativehiporyoungadultswithpersistentpainandnormalresultsof3-TMRI.MRAisthepreferredtechniquefordetectinghipcapsularandligamentumteresabnormalities(13,14).AninvestigationbyTomasevichetal(13)foundthatthesensitivityfordetectinghipcapsulardefectsafterhiparthroscopywassignificantlyhigherforMRAcomparedwithMRI(87.5%vs50%,respectively).MRAalsoshowssensitivity,specificity,positivepredictivevalue,negativepredictivevalue,andaccuracyfordetectionofligamentumterestearsof78%,97%,74%,97%,and95%,respectively(15).Theaxialobliqueplaneisparticularlyusefulfordifferentiatinggradesofligamentumteresinjuriesandimprovingspecificityfordifferentiationofpartialandcompletetears(14). AcetabularLabrumThelabrumistypicallytriangularincrosssectionandisfixedtotheacetabulumatitsbase(Fig2).Thebasehasdualattachment,spanningboththehyalinecartilage(chondrolabral)andtheacetabularbone(osseolabral).Atitschondralattachment,thelabrumstronglyadherestotheacetabularrimviaazoneofcalcifiedcartilageknownasthetidemark(16).Thechondrolabraljunctionhasavariabledegreeofblendingandevenoverlapofthelabrumwithacetabularhyalinecartilage.Thelabrumterminatesanteroinferiorlyandposteroinferiorly,whereitisbridgedbythetransverseacetabularligament.Exceptfortheregionclosesttothecapsule,thelabrumispoorlyvascularized,limitingitsabilitytohealoncetorn(17).   Figure2.Normallabralanatomy.=paralabralrecess,arrowhead=osseolabraljunction,reddottedline=labralbase.(A)Graphicillustrationshowsnormallabralanatomy.(B)CoronalT1-weightedfat-suppressed(T1FS)MRarthrogramina39-year-oldhealthyasymptomaticvolunteershowsnormallabralanatomy.Yellowdottedline=tidemark.  MRIoftheLabrumThenormallabrumtypicallyhasdiffuselowsignalintensitywithallMRIsequences.Intrasubstanceintermediateorhighsignalintensitycanbeseeninhealthyindividualsandmayrepresentmucoiddegeneration,fibrovascularbundles,ormagicangleartifact(3).Theanteriorsuperiorlabrumismostpronetosignalintensityvariations,includingglobular,linear,orcurvilinearshapes(18).Thelabrumisoftentriangular(66%–69%),althoughround(11%–16%)andflat(9%–13%)shapeshavebeenreported(18).Byconvention,labraltearsarelocalizedbasedontheclock-facemethod,where3o’clockisanterior(demarcatingtheanteriorsuperiorandanteriorinferiorquadrants),6o’clockisthetransverseligament,and12o’clockisthesuperiorapexoftheacetabulum(Fig3)(19).Thiswasshowntobeanaccuratemethodthatmatchesthearthroscopist’slocalizationandimpressionoftheextentoflabraltears,therebyprovidingastandardizedmethodofreporting(19).  Figure3.Clock-facelocalizationoftheacetabularlabrum.Graphicillustration(A)andsagittalT1-weightedfat-suppressedMRimage(B)showclock-facelocalizationoftheacetabularlabrum.Thetransverseacetabularligament(highlightedinyellow)isassignedas6o’clock,withtheacetabulumdividedintoquadrants:3o’clockisanterior,9o’clockisposterior,and12o’clockissuperior(apexoftheacetabulum).  LabralVariantsAsidefromvariationsinshapeandsignalintensity,groovesorspacesformedbythelabrumwitheithercartilage(sublabralsulci)orthecapsule(paralabralrecess)canbeconfusedwithalabraltear(18,20);theseareparticularlyconspicuouswiththedistentioneffectofMRA.Sublabralsulciarepresentinasmanyas25%ofpatientsandcanbefoundinallanatomicpositions,themostcommonbeingposteriorsuperior(48%)(Fig4)andanteriorsuperior(44%)(18).Incontradistinctionolabraltears,whichareirregularandextendintothelabralsubstance(18),themarginsofthelabrumattheinterfacewithasulcuswillbesmooth.Otherfeaturesthatfavorasulcusoverateararelessthanone-halflabralwidthfluidsignalintensitybetweenthebaseofthelabrumandtheacetabularrim;linearshape;absenceofregionalparalabral,cartilage,orosseousabnormalities;andposteriorinferiorquadrantlocation(20,21).  Figure4.Sublabralsulcus.Axialobliqueprotondensity–weightedfat-suppressed(PDFS)MRimageina22-year-oldwomanwithhipdiscomfortafteranterosuperiorlabralrepairandosteochondroplastyandwithclinicalconcernforaretearshowsaposterosuperiorsublabralsulcus(arrowhead).Thereisalsoanadjacentparalabralrecess(arrow).Yellowdottedline=osseousdefectfrompriorosteochondroplasty.Resultsofarthroscopywerenegativeforalabralretear.  Thejunctionofthetransverseligamentoverlappingwiththeacetabularlabrumcanalsoformanormalrecess(Fig5).Itismorecommonanteriorly(33%)andcanbeconfusedwithalabraltearoranteroinferiorlabral-ligamentousdetachment(18).Theparalabralrecessreferstothespacebetweenthecapsuleandthelabrum(Fig6)andcanbeconfusedwithaparalabralganglioncyst.Whilethecapsuleinsertsdirectlyatthebaseofthelabrumalongtheanteriorandposteriormarginsofthelabrum,itattachesseveralmillimetersabovethelabrumalongthesuperiormargin,therebymakingthisrecessmostobviousoncoronalsections(18).  Figure5.Transverseligament–labraljunctionrecess.CoronalT1FSMRarthrogramina38-year-oldhealthyasymptomaticvolunteershowscontrastmaterial(arrowhead)atthejunctionbetweenthetransverseligamentandlabrum,consistentwithatransverseligament–labraljunctionrecess.  Figure6.Paralabralrecess.CoronalT1FSMRarthrogramina26-year-oldfemaleasymptomaticvolunteershowscontrastmaterial(arrowhead)throughtheparalabralrecess,ananatomicspacecreatedbetweenthejointcapsuleandlabrum.  LabralAbnormalitiesLabralabnormalitiesarereadilydemonstratedatMRI.Adegeneratedlabrummaymanifestwithincreasedsize,increasedintrasubstancesignalintensity,orsurfaceirregularity(22).Labraltearsoccureitherthroughitssubstanceorintheformofadetachmentofthebasefromtheadjacentacetabulum;upto90%ofcasesrepresentlabraldetachments(23).Substancetearmanifestswithincreasedsignalintensityorcontrastmaterialthroughthelabralsubstancesurfacingthearticularsurface,capsularsurface,orboth(22,23).Approximately28%oftearsmayexhibitsignalintensitylessthanthatofgadoliniumcontrastmaterialorfluid,possiblyduetoeithergranulationtissueorvolumeaveraging(24).Withlabraldetachments,increasedsignalintensityorcontrastmaterialundercutsthebaseofthelabrum,insinuatingbetweenthelabralbaseandacetabularrimeitherpartiallyorcompletely(25).Theevolutionoflabraldetachmenttypicallybeginsatthechondrolabraljunction.Intheearlieststages,theremaybeattritionoflabraltissueinthisregion,withfluidimbibitionbetweenthelabrumandhyalinecartilage—referredtoaschondrolabralseparation—orapartiallabraldetachment.Theseparationmayextendperipherallytowardthedirectionofthecapsule,resultinginadditionaldisruptionoftheosseolabraljunctionoracompletedetachmentofthelabrumfromtheacetabularrim(26).Thechondrolabraljunctionisofparticularinterestinthecontextofcam-typeimpingement,asitservesasthefirstsiteofderangementsecondarytoshearforceandcompressioninjuryofthehyalinecartilage(26).Thismayresultinchondraldelaminationleadingfromthechondrolabraljunctionandcoursinginward(26),theso-calledcarpetlesion(27).Classificationsystemsforlabraldiseaseexistinboththeorthopedicandradiologyliterature.TheLageclassificationisthemostwell-knownarthroscopicsystemandorganizeslabraltearsasflap,fibrillated,longitudinalperipheral,orunstable(28).Czernyetal(29)devisedanMRAclassificationforlabraldiseasebasedonlocation:withinthesubstance(types1and2)orattachment(type3)(Table,Fig7).Labraltearscanbesubstancetype(type2)ordetachmenttype(type3);theauthorsfoundthattypes2and3exhibitexcellentcorrelationwitharthroscopicfindings.Ontheotherhand,Blankenbakerandcolleagues(19)foundnocorrelationbetweentheCzernyandLageclassifications.TheauthorsalsorecommendeddescribingthelabralabnormalityratherthanattemptingtocorrelateitdirectlywiththeLageclassification(19).  ClassificationofLabralInjuriesatMRASource.—Reference25.  Figure7.RepresentativeanteriorsuperiorlabraltearsatMRAandtheirCzernyclassifications.(A)AxialobliqueT1FSMRarthrogramina20-year-oldwomanwithdailyandprogressivelefthippainshowsextensionofcontrastmaterialintothelabrum(arrowhead)withoutdetachment,consistentwithaCzernystageIIAlabraltear.(B)AxialobliqueT1FSMRarthrogramina40-year-oldwomanwithrecalcitranthipandgroinpainshowsimbibitionofcontrastmaterialintothedeformedlabrum(arrowhead),consistentwithaCzernystageIIBlabraltear.(C)AxialobliqueT1FSMRarthrogramina33-year-oldwomanwithclinicalsuspicionforlabraltearshowscontrastmaterial–filledexpansionofthelabrum(arrowhead)withdetachmentattheosseolabraljunction(arrow),consistentwithaCzernystageIIIBlabraltear.  Atourinstitution,labraldiseaseisusuallyimagedusingconventional3-TMRI.Followingthisprotocolandincorporatingrecommendationsbypreviousauthors(19),weusethefollowingterminologyfordescribingcommonlabralpathologicconditions:(a)degeneration=increasedintra-substancesignalintensitywithoutsurfacing,(b)substancetear=increasedintrasubstancesignalintensityextendingtothecapsularorarticularsurfaceofthelabrum,(c)partialdetachmenttear=partial-widthincreasedsignalintensityextendingbetweenthebaseofthelabrumandacetabularrimatthechondrolabralorosseolabraljunction,(d)completedetachmenttear=increasedsignalintensitybetweenthelabrumandacetabularrimextendingacrossthefullwidthofthelabralbase,and(e)complextear=multidirectionalormultipleincreased-signal-intensitytearlines,extendingtoboththedeeparticularandcapsularsurfaces(Fig8)(22).  Figure8.Normalandabnormalanteriorsuperiorlabrum.(A)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina27-year-oldasymptomaticvolunteershowanormallabrumwithhomogeneouslowsignalintensity(arrowhead),preservedtriangularshape,andsmoothborders.(B)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina36-year-oldwomanwithhippainandclinicalconcernforlabraltearshowasmallareaofincreasedsignalintensity(arrowhead)withinthelabralsubstancenotreachingasurface,consistentwithlabraldegeneration.(C)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina43-year-oldwomanwithsymptomsofimpinge-mentshowfocallinearincreasedsignalintensity(arrowhead)withinthelabralsubstancebreachingthearticularsurface,consistentwithasubstancetear.(D)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina37-year-oldwomanwithpersistenthippain,querylabraltear,showpartial-widthincreasedsignalintensity(arrowhead)atthechondrolabraljunctionnotextendingpastthechondrolabraljunction,consistentwithchondrolabralseparationorpartiallabraldetachment.(E)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina78-year-oldwomanwithsymptomsofimpingementshowincreasedsignalintensity(arrowheads)extendingcompletelyfromthechondrolabraljunctiontothelabralbase,consistentwithcompletelabraldetachment.(F)Graphicillustration(left)andaxialobliquePDFSMRimage(right)ina51-year-oldwomanwithlefthippainworsewithrunningshowmultipleincreased-signal-intensitylines(arrowheads)extendingtobothdeeparticularandcapsularsurfaces,consistentwithacomplextear.Asmallparalabralcyst(arrow)atthecapsularsurfaceisalsopresent.  Chroniclabraltearanddegenerationcanresultinlabralossification,whichmayexacerbateimpingementsymptoms.AtMRI,ossificationappearsasasmallfocusofsignalintensitysimilartothatofbonemarrow(26)—althoughitmayevenbeoccult—andisthereforebestevaluatedonradiographsorT1-weightedimages(Fig9).Thepresenceofossificationshouldbereported,asitmayleadtoamoredifficultrepair,makinglabraldébridementtheoptimalapproach(30).  Figure9.Completelabraldetachmentwithossificationina32-year-oldmalecyclist.CoronalT1-weighted(A)andPDFS(B)MRimagesshowasmallfocusofossification(arrowinA)adjacenttothesuperolateralacetabulumwithmarrow-equivalentsignalintensity,consistentwithossification.Thereisafluid-filledcleft(arrowheadinB)extendingcompletelyfromthechondrolabraljunctiontothelabralbase,consistentwithcompletelabraldetachment.  Contrarytotearsinitsglenoidcounterpart,acetabularlabraltearsmostcommonlyoccurintheanteriorsuperiorquadrant(23).Tearsoftheposteriorsuperiorquadrant(Fig10)areusuallyseeninyoungerpatients,indysplastichips,orafteraposteriorhipdislocation(19).Posteriorinferiorlabraltears(Fig11)arerareandshouldnotbeconfusedwiththerelativelycommonnormalgrooveorsulcus,whichiswelldepictedatMRA(31).  Figure10.Posteriorsuperiorlabraltearina46-year-oldwomanwithlockingandhippain.SagittalPDFSMRimageshowsincreasedsignalintensitywithintheposteriorsuperiorlabrum,consistentwithalabraltear,withanadjacentsmallparalabralcyst(arrow).  Figure11.Posteriorinferiorlabraltearina48-year-oldmanwithdeeplefthippainradiatingtothegroin.Axialoblique(A)andsagittal(B)PDFSMRimagesshowafluid-filledcleft(arrowheadinA)withanadjacentcyst(arrowinB),consistentwithalabraltearwithasmallparalabralcyst.  Aparalabralcystcanarisewhensynovialfluidleaksthroughalabraltearcleftandintotheperiarticularsoft-tissuespaceandbecomesencapsulated.Itaidsinrecognitionofalabraltearandisoftenlocatedintheanteriorsuperiorquadrant(32).ParalabralcystsusuallyhavelowtointermediatesignalintensityonT1-weightedimagesandhighsignalintensityonT2-weightedimages,althoughsignalintensitycanvary(33).Owingtotheirthickgelatinouscontent,theymaynotalwaysfillwithgadoliniumcontrastmaterialatMRA(22).Avastmajorityofparalabralcystsareaccompaniedbyfull-thicknesslabraldetachmenttears(94%)(Fig12);thelackofalabralteartherebyraisesthepossibilityofanotherdiagnosis,suchassynovialcyst,focalsynovitis,tumor,orpsoasbursalfluid(33).  Figure12.Anteriorsuperiorlabraltearwithaparalabralcystina68-year-oldwomanwithrighthippainandanincidentalsoft-tissuemassatpreviousCT.SagittalPDFSMRimageshowsaprominentfluid-filledcleft(arrowhead)intheanteriorsuperiorlabrumwithanadjacentlargecysticmass(arrows),consistentwithacompletelabraldetachmenttearwithaparalabralcyst.  FemoroacetabularImpingementFAIisawell-recognizedriskfactorinthedevelopmentandevolutionoflabraltearsandhiposteoarthritis.Itisassociatedwithanatomicalterationsthatimpairinteractionsbetweenthefemurandacetabulumduringmotionofthehipjoint,predisposingthelabrumtotearsandarticularcartilagetoprematuredegeneration.Itisclassifiedaccordingtobonedysmorphismascam(femoralside),pincer(acetabularside),oracombinationofbothtypes(mixed).Cammorphologyischaracterizedbyexcessboneorcartilageatthefemoralhead-neckjunction,diminishingthefemoralheadsphericityandhead-neckoffset.Pincermorphologypredisposestoimpingementduetoovercoverageofthefemoralheadbytheacetabulum.Itmaybefocal,asseenwithacetabularretroversion,orglobal,asisseenwithcoxaprofundaandacetabularprotrusio.Incammorphology,labralandchondraldisordersoccurpreferentiallyintheanteriorsuperiorquadrantofthejoint.Withpincermorphology,abutmentoftheanterioracetabularrimontothefemoralneckresultsinfocalimpactionandtearingoftheanteriorsuperiorlabrum,whicheventuallyextendsposteriorlyandultimatelycircumferentially(34). TreatmentandPostoperativeAppearanceLabraldiseasecanbemanagedwithconservativeorsurgicaloptions.Ingeneral,increasedlabralsubstancesignalintensitythatdoesnotbreachasurface(degenerativesignalintensity)isconservativelymanaged.Whiletheintraoperativeappearanceofthelabrum(ie,labralquality)(35)isthemostimportantoverallfactoraffectingsurgicaldecisionmaking,asurveybyHerickhoffandSafran(36)showedthatsurgeonsconsiderMRIorMRAfindingstobethemostimportantpreoperativefactor.Indicationstorepairatornacetabularlabrumandtypesoftreatmentarehighlyvariableamonghiparthroscopicsurgeons(35,36).Therearethreeformsoflabralsurgery:débridement,refixationorrepair,andreconstruction.Labraldebridementinvolvestrimmingoffrayedandunhealthytissue,potentiallyleavingviabletissuewithgoodhealingcapacity(37,38).Labralrefixationorrepairinvolvesreattachmenttotheacetabularrimusingsutureanchors(38).Substancetearsaretreatedwithdébridementwithorwithoutrepair,whilepartialorcompletedetachmentsaremanagedwithrepair.Incaseswherethereisinsufficientlabraltissuethatprecludesadequaterepair,suchasinasmallordiminutive(hypotrophic)labrumlessthan3mmwide,complextear,ormaceratedlabrum,labrumreconstructionusinganauto-orallograftcanbeperformed(38).Anormalpostoperativelabrumshouldbefirmlyaffixedtotheacetabularrimandremainintactoverthesutureanchorzone(39).Itistypicallyshorteranddiminutivebutshouldremainsmooth(40).Thesuturesthemselvesshouldbepositionedclosetotheacetabularrimbutshouldnotpenetratethesubchondralboneorthearticularcartilage(41,42).Kimandcolleagues(43)foundobliterationoftheparalabralrecessin94%–100%ofhiparthroscopyprocedures;thismaybeanormalpostoperativefindingrelatedtoadhesionsorscarring(Fig13)(43),althoughthisfindingmaybeworthreportinginthepresenceofsymptoms(43).Incontrasttothenativelabrum,increasedsignalintensityintheoperatedlabrumthatsurfacesisnotnecessarilyaretearandmayrepresentgranulationtissueorahealedtear(Fig14)(22,40).Increasedfluid-orgadolinium-intensitysignalwithinthelabrumthatsurfaces,extensionoflabralabnormalitybeyondthesutureanchorzoneorbeyondthemarginsoftheoriginaltear,paralabralcyst,andlabraldistortionaresignsofaretear(Fig15)(40).  Figure13.Postoperativeobliterationoftheparalabralrecessina40-year-oldwomanwithpersistentlimitedrangeofmotionafterlabralrepair.CoronalPDFSMRimagesbefore(A)and1yearafter(B)arthroscopiclabralrepairshowobliterationofthepreviouslyintactsuperiorparalabralrecess(arrowinA)andreplacementwithill-definedintermediate-signal-intensitytissue(arrowheadsinB),mostinkeepingwithfibrosisorscarring.  Figure14.Normalpostoperativelabrumina48-year-oldwomanimagedforassessmentofaretear.SequentialPDFSMRimagesatamoreanterior(A)andposterior(B)levelshowsignalintensitywithinthelabrumthatsurfacestobothcapsularandarticularsides(arrowheadsinA),whichmaybeworrisomeforaretearinanativelabrum.Thesutureanchorsareplacedclosetotheacetabularrim(arrowsinB)butdonotbreachthesubchondralboneorarticularcartilage.Arthroscopydemonstratedanintactposteroperativelabrum.  Figure15.Labralretearina36-year-oldwoman.CoronalT1FSMRarthrogramshowsdistortionoftheanteriorsuperiorlabrumwithimbibitionofcontrastmaterial(arrowheads),consistentwithalabralretear.  TheosseousdysmorphismresponsibleforFAIisusuallytreatedalongwiththelabraltear.Thetwomostimportantfactorstoconsiderinchoosingthetechniquearevisualizationoftheentirelesiontoachieveathoroughcorrectionorrepairwhilemaintainingthebiomechanicalfunctionofthejoint(44).Osteochondroplastyisthemostpopularmethodformanagingcamdeformitiesandinvolvescorrectiveresectionofthecammorphologyusingahigh-speedburr(Fig16)(44).AtMRI,theosteochondroplastybedappearsasasmoothdefectofvariablesizeatthefemoralhead-neckjunction(45).  Figure16.Labralrepairwithsutureanchorina39-year-oldwomanwithlabraltear.(A)Intraoperativeimagebeforeresectionshowsaprominentfemoralhead-neckjunction(yellowdottedline),consistentwithcamdeformity.(B)Intraoperativeimageafterthecamhasbeenresectedshowsbonyconcavityofthefemoralhead-neckjunction(yellowdottedline),consistentwithpostexcisionchanges.  Pincerlesionsaremanagedbyalabraltakedownandacetabularrimresectionfollowedbyreattachmentofthelabrumtotheacetabulumwithsutures(45).Theresectedportionappearsasadefectortruncationoftheacetabularrimwithorwithoutsuturesfromlabralsurgery(Fig17).Theappearanceoflabralprocedures,osteochondroplasty,andacetabularresectiondefectsmaybesubtle,attimesevenmimickingtheirnormalpreoperativecounterparts,necessitatingcarefulcomparisonwithpreprocedureimagesandoperativenoteswhenavailable.  Figure17.Acetabularrimresectionandlabralrepairwithoutcapsularrepairina36-year-oldmanwithmixed-typeleftFAI.(A)PreoperativeaxialobliquePDFSMRimageshowsanintactanteriorsuperiorlabrumattachingtoanormalanteriorsuperioracetabulum(arrows).(B)PostoperativeaxialobliquePDFSMRimageshowsbonytruncationoftheanteriorsuperioracetabulum(arrows)andanadjacentfluid-filleddefectintheanteriorsuperiorcapsule(yellowdottedline)representingthearthroscopyportal.Alabralsutureisalsoshown(arrowheads).  CapsuleandCapsularLigamentsoftheHipThehipcapsuleisacriticalstaticstabilizerofthehipandcontainsbothlongitudinalandcircularfibers(Fig18)(46).Thelongitudinalfibersarereinforcedbythreeligaments:iliofem-oral(ILFL),pubofemoral(PFL),andischiofemoral(ISFL).TheILFLorligamentofBigelowisthestrongestofthethree(46),limitingexternalrotationinflexionandbothinternalandexternalrotationinextension.Itconsistsofsuperiorandinferiorbandsthatextendfromthelowerpartoftheanteroinferioriliacspineandiliacmarginoftheacetabulumtotheintertrochantericline,formingareverse-Yconfiguration(46).  Figure18.Graphicillustrationsshowtheosseousfootprints(A)andcourse(B)ofthecapsularfibersandligaments.Lightblue=superiorbandoftheiliofemoralligament(ILFL),pink=inferiorbandoftheILFL,green=ischiofemoralligament(ISFL),yellow=pubofemoralligament(PFL),orange=capsularfibers,whitebandinB=zonaorbicularis.  ThePFLstabilizesthejointmostnotablyduringabduction.Itcoursesanteriorlyfromtheobturatorcrestandsuperiorpubicramustothefemoralneckadjacenttothelessertrochanter,blendingwiththeinferiorfibersoftheILFL.TheISFLcontributestojointstabilityduringextension.Itcoursesfromtheischialaspectoftheacetabularrimtothegreatertrochantericbaseposteriortothehip.ThezonaorbicularismakesupthecircularfibersandrepresentsacircumferentialcapsularthickeningattachingsuperiorlytothefemuratthebaseofthegreatertrochanterbeforeconvergingwiththesuperiorbandoftheISFL(46).Itensheathstheposteriorcircumferenceofthefemoralnecklikeaslingandformsthedistalfreeborderoftheposteriorportionofthearticularcapsule.Whileconventionallythoughttobeinconsequentialtojointfunctionandbiomechanics,recentstudieshavepostulateditsrolesinrestrainingjointdistraction(47)andcirculatingsynovialfluidbetweenthecentralandperipheralcompartments(46). MRIoftheCapsularLigamentsAtMRI,thecapsularstructureshavehomogeneouslylowsignalintensitywithallsequences.TheILFLbandsandISFLarebestidentifiedintheaxialandaxialobliqueplanes(Fig19).CoronalsectionsattheanteriorcapsuledepicttheILFL,whilesagittalsectionsdemonstratethePFL(Fig20)(48).ThezonaorbicularisisdepictedatbothMRIandMRA;intra-articulargadoliniumcontrastmaterialenhancesvisualizationoftheligamentanditssynovialfolds(49).Althoughoftendescribedasformingacollararoundthefemoralneck,itappearsasafullcircleinonly20%ofcases(49).  Figure19.NormalMRIoftheILFLina26-year-oldmaleasymptomaticvolunteer.(A)AxialobliqueT1-weightedMRarthrogramatamoresuperiorlevelshowsthesuperiorbandoftheILFLinsertingontothesuperioraspectoftheintertrochantericline(arrowhead).Medially,theinferiorbandoftheILFL(thickstraightarrow)isseenasadistinctthickeningontheanteriorcapsule.TheISFLappearsasathickeningoftheposteriorcapsule(curvedarrows).Thezonaorbicularis(thinstraightarrow)isafocalprominencethatformsthedistalfreeborderoftheposteriorcapsule.(B)AxialobliqueT1-weightedMRarthrogramatamoreinferiorlevelshowstheinferiorbandoftheILFL(arrow)insertingontotheinferioraspectoftheintertrochantericline(arrowhead).  Figure20.NormalMRIofthePFLina26-year-oldmaleasymptomaticvolunteer.SagittalT1FSMRarthrogramshowsanintactPFL(arrows).Theiliopsoastendonisseenintheanterioraspectofthejoint(arrowheads).  Capsuleandcapsularligamentinjuriesusuallyfollowdefinitivehipdislocationsafterhigh-energycontactsportinjuriesorimpactionofthekneeagainstacardashboardwiththehipflexed(50).Thedirectionisfrequentlyposterior,wheretheheadofthefemurliesposteriortotheacetabulumandtheinjuredlowerextremityexhibitsshortening,medial(internal)rotation,flexion,andadduction(51).Onanteroposteriorradiographs,anteriorandposteriordislocationsmayappearsimilar.However,inaposteriordislocation,thefemoralheadisusuallylocatedposterior,superior,andlateraltotheacetabulum(FigS2).ThepreciseroleofMRIintreatmentalgorithmsforacutehipdislocationisnotclearlydefined,butitmaybeusefulinearlyrecognitionofsoft-tissueinjuries(Fig21)(52)anddetectionofintra-articulardamagesuchaschondralinjury,labraltear,ormissedintra-articularbody(53).Theimagingtriadofposterioracetabularlipfracture,ILFLdisruption,andhemarthrosiswasfoundtobepathognomonicofposteriorhipdislocationinacaseseriesofeightfootballplayers(54).  Figure21.HipdislocationatMRI.AxialT1FSMRarthrogramina23-year-oldwoman3daysafterareportedposteriorhipdislocationshowsaprominentdefectintheISFL(arrowheads)consistentwithacompletetear,withextravasationofcontrastmaterialintothesofttissues(arrows).  Anteriordislocationisfarlesscommon,occurringinlessthan8%oftraumatichipdislocations(52).Themechanismofinjuryisforcedhipabductionandexternalrotation;thefemoralheaddislocatesanteroinferiorlywhenthehipisflexedandanterosuperiorlywhenthehipisextended(52).Thetransverseligament,ligamentumteres,posteriorcapsule,andPFLmaybeinjuredinanteriorinferiordislocations(52).Dataonanteriorsuperiordislocationsarelimited,althoughinjuriestotheligamentumteres,ILFL,andsuperiorcapsulehavebeenreported(52). PostoperativeAppearanceCapsularrepairortighteningprocedureshaveyettogainuniversalacceptanceamonghipsurgeons,eventhoughavastmajorityofhigh-volumearthroscopistsrecommendthemforcapsularredundancyorlaxityorafterarthroscopy(55).Theseproceduresimprovehipstabilityanddecreasetheriskofpostoperativehipdislocationattheexpenseofiatrogenicfemoralheadchondraldamage,capsuleovertightening,andhipinfectionduetolongerexposuretime.Capsularrepairorplicationusessuturestoclosethecapsular“barearea”atthesiteofpriorarthroscopy.Itisrecommendedforcapsularredundancy,symptomaticcapsularlaxity,orgeneralizedligamentouslaxityduetoanunderlyingconnectivetissuedisorderorafterarthroscopy(56).AtMRI,therepairedcapsuleisusuallysignificantlythickerthroughtheILFLatthesiteofroutinecapsulotomyandclosurecomparedwiththecontralateralnonoperativehip(57).Othercapsulartighteningproceduresarethermalcapsulorrhaphyandcapsularreconstruction(50,56).Capsularlesionsintheabsenceoftraumatichipdislocationmayberelatedtoopenorarthroscopiccapsulotomyorcapsulardehiscence.Intheabsenceofcapsularrepair,postoperativechangestotheadjacentstructures,capsularirregularity,edema,orafrankdefectmayindicatethesiteofarthroscopytrocarplacement(Fig22).Capsulardehiscenceisapossiblecomplicationofcapsularrepair.ItisappreciatedatMRIasadisruptedordiscontinuouspseudocapsule,oftencharacterizedbyafluid-filledgapwithorwithoutassociatedpseudocapsularthickeningandhyperintensity(58).Spontaneoushealingofthecapsulecanbeseenasearlyas6weeks,dependingonthearthroscopicapproach(Fig23)(59).  Figure22.Postarthroscopycapsuledefectina41-year-oldwomanwhounderwentrecentlabralrepairwithoutcapsularrepair2weeksearlier.CoronalT1FSMRarthrogramshowsawell-demarcatedcontrastmaterial–filleddefectoftheILFL(arrowhead)withsurroundingsusceptibilityartifacts,consistentwithapostarthroscopycapsuledefect  Figure23.Capsularhealingina46-year-oldmanwithpersistentimpingementsymptomsaftersurgery.(A)PostoperativePDFSMRimage2weeksaftercapsulectomyandosteochondroplastyshowsanewlyexcisedfemoralhead-neckjunction(arrow)withoverlyingill-definedsoft-tissueedema(arrowheads),consistentwithcapsulectomychanges.(B)PostoperativePDFSMRimage5.5monthsaftertheprocedureshowsintervalresolutionoftheedemaandfillinginofthecapsule(arrowheads),consistentwithcapsularhealing.  LigamentumTeresTheligamentumteresisatubularligamentsituatedbetweentheperipheralinferioracetabularnotchandthefoveaofthefemoralhead.Itarisesfromthetransverseacetabularligamentalongtheinferiormarginoftheacetabulumandattachestotheperiosteumofthefoveabytwobands:ischialandpubic.Awarenessandinterestintheligamentumtereshaveincreasedwiththeexpansionofhiparthroscopy.Initiallyconsideredaninconsequentialvestigialstructure,recentstudieshaverecognizeditsroleinfemoralheadvascularity,proprioception,nociception,androtationalstabilityofthehip(14).Martinandcolleagues(60)describeditsroleinhipstabilityusingaball-and-stringmodel(Fig24).  Figure24.Graphicillustrationsdemonstratethemechanismofhipstabilityprovidedbytheligamentumteres,accordingtotheballand-stringmodel.(A)Asthehipjointisabducted,theligamentumtereswrapsunderthefemoralheadwhilepullingitintotheacetabulum,limitinginferiorsubluxation.(B)Asthehipjointisexternallyrotated,theligamentumtereswrapsaroundthefemoralheadwhilepullingitintotheacetabulum,limitinganteriorsubluxation.  MRIoftheLigamentumTeresLigamentumteresinjuriesareassociatedwithhipdislocation,flexion-adductionstress(ie,fallonipsilateralkneewiththehipflexed),orabruptexternalrotationofthehipsuchasintwisting(14).Variousclassificationsystemshavebeenproposed(61).GrayandVillar(62)firstclassifiedinjuriesbasedoninjurymechanismaswellasarthroscopicfindings.TheDombclassificationwasdevelopedtoquantifythedegreeofligamentruptureintype2lesionsorpartialtears(63).PorthosSalasandO’Donnell(64)proposedathirdclassificationtofurtherdelineatethecauseofthetearandincorporatetreatmentoptions.Finally,O’DonnellandArora(65)accountedforligamentouslaxityinadditiontotheligament’sappearance.AtMRI,theligamentappearsasasmooth,predominantlyhomogeneous,andlow-signal-intensitystructurewithallpulsesequences.Itisbestdepictedonaxialandcoronalimages,appearingasabilobedslightlystriatedligamentcomprisedofonetothreebundles(Fig25)(14,66).Ithasanaverageoveralllengthof28mmandmeasuresapproximately3–4mminthickness,graduallytaperingfromproximaltodistal(66).Slightlyincreasedsignalintensitynearitscurvedattachmenttothefoveacapitisfemorisonshortertimetoecho(TE)–basedimagesmaybeattributabletothe“magicangle”artifact(14).  Figure25.NormalMRIoftheligamentteresintwopatients.(A)CoronalT1FSMRarthrogramina24-year-oldfemaleasymptomaticvolunteershowsanormalsinglebundleoftheligamentumterescoursingfromthefoveacapitis(arrowhead)tothetransverseacetabularligament(arrow).(B)CoronalT1FSMRarthrogramina30-year-oldfemaleasymptomaticvolunteershowsanormaldoublebundleoftheligamentumterescoursingfromthefoveacapitis(arrowhead)tothetransverseacetabularligament(arrow).  Partialandcompletetearsaremostcommoninthefoveacapitis;thoroughinspectionofthisregionisthereforeimportant(14).WhileMRAhasbeenshowntobeaccurateindiagnosingligamentumterestears,literatureontheaccuracyofconventionalMRIissparse.AnintactligamentandapartiallytornligamentcanhavesimilarimagingfindingsatMRA,makingdiagnosisofpartialligamentumterestearsdifficult(66).Highsignalintensitywithinthesubstanceofthefibersandperipheralirregularityaresuggestiveofapartialtear(Fig26)(66).Acompletetearmanifestswithfull-thicknessfiberdiscontinuityandligamentlaxity.  Figure26.Partialtearoftheligamentumteresina29-year-oldfemalesprinterwith4weeksofgroinpain.CoronalPDFSMRimageshowsfocaldiscontinuityofthesuperiorandmedialfibers(arrowhead)oftheligamentumteres,consistentwithapartialtear.  AnondisplacedfracturefragmentmayaccompanyeitherapartialorcompletetearbutmaybeoverlookedatMRI,requiringcarefulevaluationofmarrowsignalintensityonprotondensity–weightedfat-suppressed(PDFS)orT2-weightedimages(14).ConventionalCTorCTarthrographymaybemoreoptimalforevaluatingfragmentscomparedwithMRIorMRA(Fig27).Achronicallytornligamentiselongated,irregular,lax,orattenuatedwithfibersremainingcontiguous.Absenceofedemaintheacetabularfossa,synovitis,andjointeffusionallowdistinctionofchronicfromacutetears(Fig28)(14).  Figure27.Acuteavulsionfractureoftheligamentumteresina22-year-oldmanafterlefthipdislocation.(A)CoronalPDFSMRimageshowsanacuteavulsionfractureofthefovealattachmentoftheligamentumteres(arrowhead)andassociatedmarrowedemaintheacetabulum(arrows).(B)CoronalCTimageshowsasmallavulsedfragment(arrowhead).Thereisalsoanundisplacedfractureoftheadjacentmedialwalloftheacetabulum(arrow).  Figure28.Chronictearoftheligamentumteresina45-year-oldformerbasketballplayerwith6yearsofinguinalpainexacerbatedbysquatting.CoronalPDFSMRimageshowsmarkedthickeningoftheligamentumteresatthefoveacapitis(arrowheads)withpreservedfibercontiguity,consistentwithachronictear.  TreatmentComparedwithtreatmentsforlabralandcapsuledisease,therearelimiteddataonmanagementofligamentumteresinjuries.Formostcases,conservativemanagementisadequate.Tearsarecurrentlytreatedarthroscopically(67),andindicationscontinuetoevolve.Currentindicationsarepain,instability,andmechanicalsymptomswithMRIfindingsofligamentthickening,partialorcompletetears,oravulsionfractureoftheligamentwithintra-articularosteochondralfragmentsandedemaintheacetabularfossa(14).Treatmentoptionsareshrinkage,débridement,andmostrecentlyreconstruction.Shrinkageanddébridementarereservedforpartialtearsafterfailedconservativemanagement.Fibroblasticresponsefromthermalshrinkageimprovesthebiomechanicalstrengthoftheremainingfibers,whiledébridementoffrayedandthestumpoftornfibersrelievesmechanicalsymptomsandpain(14).Reconstructionwithallografts,autografts,orsyntheticgraftsisindicatedforcompletetearsthatareconsideredreparable,causeinstability,orfailedpreviousdébridement(67). HipInstabilityHipinstabilityisabroadtermusedtodescribevariousabnormalitiesmanifestingwithdeep-seatedpainaroundthehip,groin,oringuinalregion.Thetermhasbeenusedinterchangeablywithjointhyperlaxityorhypermobilityandmicroinstability(68).Awarenessoftheentityhasincreasedrecently,althoughitsdiagnosisandevenitsexistencearestilldebated.Disordersofthecapsulolabralstructureshavebeenimplicatedinsymptomsofhipinstability.Anexhaustivediscussionisbeyondthescopeofthisarticle,butthissectionwillemphasizecurrentclassificationandterminology.Hipinstabilitymaybe(a)duetoasingleacuteepisodeoftrauma,(b)duetooveruseorrepetitivemicrotraumainayoungorathleticpatient,(c)iatrogenicinthesettingofpriorarthroscopyandcapsulotomy,(d)developmentaloranatomicsuchasinhipdysplasiaorconnectivetissuedisorders(ie,hyperlaxity),or(e)idiopathicormicroinstabilitywhentheclinicalpresentationisvagueorintheabsenceofthepreviouslymentionedcriteria(68).Traumaticinstabilitysecondarytoanacutedislocationeventmaybedistinguishedfromoveruseinstabilityonlywithareliableclinicalhistoryandphysicalexamination.Iatrogenicinstabilityisararepostarthroscopycomplication.Osseousriskfactorsincludeexcessiveboneremovalduringacetabularrimresectionorfemoralosteoplasty(FigS3).Largecapsulotomieswithoutcapsularrepairandnonhealingcapsulardefectsfrompreviousarthroscopyareexamplesofsoft-tissueriskfactors(56,69).O’Neilletal(70)describedagradingsystemforcapsularchangesatMRAinpatientswithsymptomaticpostsurgicalhipinstability.Thissystemincludesnormalcapsularappearanceandvolume,increasedcapsularredundancy(Fig29),focalcapsularrentorcapsularirregularity,andgrosscapsulardefect.Intheircohortof31patients,nocapsulesappearedcompletelynormalaftertheprocedure(70).Contrarytotraumatichipinstability,postarthroscopicinstabilityismostoftenanterior(theanteriorlateralcapsulebeingthemostcommonportalforarthroscopy)andoccurswithhipextensionandexternalrotation(71).DevelopmentaloranatomicinstabilityisseeninpatientswithdysplastichiporFAI,connectivetissuedisorders,orhypermobilitysyndromes(Ehlers-DanlosorMarfansyndrome).Thealteredbonearchitectureintheseconditionspredisposestoearlychondropathyandlabraltearsintheabsenceoftrauma,athleticactivity,orsurgery.Finally,idiopathicinstabilityormicroinstabilityreferstopainfulextraphysiologichipmotionwithoutovertsubluxationordislocation(42).Whilecausesofmicroinstabilitycanbethesameasoroverlapwiththoseofthetypesmentionedearlier,itisoftenseeninpatientswholackadefiniteunderlyingcause.Asaresult,diagnosisreliesonathoroughclinicalhistory,physicalexamination,andimagingevaluation.Currently,therearenopathognomonicimagingfeaturesofmicroinstability.Arecentsystematicreviewfoundthatintheappropriateclinicalcontext,hipdysplasia,anteriorlabraltears,andligamentumterestearsmaybesuggestiveofmicroinstability,althoughtheauthorsrecommendfurtherstudies(42).Capsularlaxityisimplicatedinmicroinstabilitybutisnotadiagnosisperse(72).Itisatermusedtodescribetheinabilityofthejointtodelivernormalresistancetoexternalforces(72).Theterminologyisoftenusedinbiomechanicalandclinicalstudies.althoughafewinvestigationssuggestimagingcorrelates.Aprospectivestudyof100consecutivepatientsshowedlowerhypermobilityscoresinsubjectswithacapsularthicknessofgreaterthanorequalto10mm(73).AnotherstudybyMagerkurthetal(74)concludedthatawidenedanteriorhipjointrecess(>5mm)andathinnedanteriorjointcapsule(<3mm)correlatewithintraoperativefindingsoflaxity. ConclusionThehipisauniquelyconstrainedjointwithcriticalstaticstabilityprovidedbythelabrum,capsuleandcapsularligaments,andligamentumteres.Understandingtheanatomy,patternsofinjury,MRIfeatures,treatment,andpostoperativeappearanceallowsprecisediagnosisandtimelymanagement.

膝关节周围截骨术（PTO，HTO，MOHTO，LCHTO，DFO，MCDFO，LODFO，DLO，SCO，ACWO，AOWO，ATTO，FVTVO，1S-TKA-FO）的优化指征与技术(2022)OptimizingindicationsandtechniqueinosteotomiesaroundthekneeFerreraA,MenetreyJ.Optimizingindicationsandtechniqueinosteotomiesaroundtheknee[J].EFORTOpenRev,2022,7(6):396-403.转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/35674119/转载文章的原链接2：https://eor.bioscientifica.com/view/journals/eor/7/6/EOR-22-0057.xmlAbstractOsteotomiesaroundthekneerepresentavalidsurgicaltreatmentinyoungactivepatientsaffectedbyunicompartmentalosteoarthritisand/orkneeligamentinstability.Thisreviewarticledescribesthemainosteotomiesperformedaroundthekneeandtheiroptimization,withparticularattentiontoindicationsandsurgicaltechniqueinlightofthemostrecentliteratureandauthorexperience.Furtherdevelopmentshavetobeexpectedfromtechnologicaladvances,focusingparticularlyonsurgicalplanningandthecontrolofintraoperativedeformitycorrectionbypre-shapedcuttingblocks.Keywords:instructionallecture;osteotomies;kneeIntroductionThehistoryofosteotomiesstartsinthe16thcentury,buttherealdevelopmentofthesetechniqueshasimprovedbetweenthe19thand21stcenturies,tobecomethegoldstandardtreatmentfortheunicompartmentalosteoarthritisoftheknee.Thegrowthofarthroplastysurgeryandthesubsequenttechnologicdevelopmentofnew,reliableandbetterperformingprostheses,mostlyimplantedinelderlypatientswithlowfunction,ledtoaprogressivelossofinterestforosteotomies.However,overtheyears,studies(1)underlinedunsatisfactoryclinicalresultsforkneearthroplastiesinmoreactiveandsportivepatients.Inthissetting,osteotomiesmadetheircomebackinthetherapeuticarsenalofunicompartmentalosteoarthritis.Indicationswerebettertailoredtopatients(Fig.1andTable1),andtechniqueswerefurthermoredevelopedandmakingthedegreeofcorrectionmorereliable.Advanceddevelopmentoffixationplatesandmodernpostoperativerehabilitationprotocolshavemadeosteotomiesmoreattractive.Figure1Lowerlimbangles.Table1Physiologicaljointangles.JointanglesAcronymStandardvaluesAnatomicalfemorotibialangleaFTA173–175°AnatomicalmechanicalfemoralangleaMDFA6±1°AnatomicallateraldistalfemoralangleaLDFA81±2°MechanicallateraldistalfemoralanglemLDFA87±3°AnatomicalmedialproximaltibialangleaMPTA87±3°MechanicalmedialproximaltibialanglemMPTA87±3°AnatomicallateraldistaltibialangleaLDTA89±3°MechanicallateraldistaltibialanglemLDTA89±3°JointlineobliquityJLO0–4°PosteriortibialslopePTS5–7°Thepurposeofthisreviewarticleistodescribethemainosteotomiesaroundthekneeandhowtooptimizetheirindicationsandsurgicaltechniquesinlightofthemostrecentliteratureandauthors’experience.Proximaltibialosteotomies(PTO)Proximaltibialosteotomy(PTO)isacornerstoneprocedureinthetreatmentofmedialcompartmentosteoarthritisinavarusknee,inwhichweight-bearingforcesaremostlytransmittedacrossthemedialtibiofemoralcompartment,leadingtoeventualandprogressivedamagetothearticularcartilageandthesubchondralbone.Theaimofthisprocedureistoshiftthemechanicaxisoftheknee,leadingtoadecreasedareaofcontactandprogressiveunloadingoftheaffectedcompartment.Finally,theobjectivesaretoreducepainforthepatients,increasetheirfunction,delaytheprogressionofmedialarthrosisandtheneedforkneereplacementsurgery.IndicationsTheidealcandidateforPTOisayoungpatient(＜65years),moderatelyactive,withmedialisolatedosteoarthritis,malalignment＜15°,tibialbonevarusangle＞5°andaminimumrangeofmotion＞90°offlexionontheaffectedknee.Relativecontraindicationsareage＞65years,impairedrangeofmotionwith＜90°offlexionand≥15°offlexioncontracture,≥20°ofcorrectionandrheumatoidorinflammatoryarthritis.PTOshouldbeconsideredonanindividualbasis.Non-suitablepatientsareobese(BMI＞30)andpatientswithbicompartmentalarthritisorwithpreviouslateralmeniscectomy(2).Smokingplaysanegativeroleespeciallyasitmayinterferewithbonehealinginopen-wedgePTOandmaycausenonunion.InstabilityusedtobeacontraindicationinPTO,butnowadayssagittalandcoronalalignmentmodificationthroughthissurgicaltechniquemayrepresentausefulsolutioninapatientwithanteriorcruciateligament(ACL)ruptureandposterolateralcornerinjuries(PLC).VarusdeformityresultsinthetensileforceonACLtoincrease,andavarusalignment＞5°isrecognizedasariskfactorforfailureofACLreconstruction.Nowadays,PTOmightbeperformed,ifdegenerativechangesoccur,inpatientswithvaruskneeplusACLruptureintheabsenceofdynamicinstabilityonweight-bearinglateralradiographs.ACLreconstructionmaybecombinedwithPTOorperformedasasecondsurgicalstage,usuallyinpatientswithpainfulinstabilitycombinedwithmedialdegenerativechangesinavarusknee(3).ChronicPLClaxityleadstoadecreasedabilityforwithstandingaloadingstressappliedtothekneeandvarusalignmentworsensthissituation.Therefore,accordingtoArthuretal.(4),correctionofthevarusalignmentthroughPTOalonecanresultinbetterkneestabilityandgoodclinicaloutcomes,whileonly38%oftheircohortneededasecondstageprocedureconsistingofligamentreconstruction.TechniquesManyPTOtechniqueshavebeendevelopedandusedinhistory,buttoday,opening-andclosing-wedgeosteotomyarethemostcommonlyused(seeTable2).Inthelateralclosing-wedgetechnique,correctionisachievedbyremovingabonewedgefromthelateraltibia,retainingthehingeandclosingthegap.Ithasbeenwidelyusedinthepastforitshighrateofconsolidation,butprogressivelylostpartofitspopularityduetosomedisadvantages,suchasshorteningoftheleg,theneedforfibularosteotomy,theinterruptionofproximaltibiofibularjointandtheriskofperonealnerveinjury.Ontheotherhand,inthemedialopen-wedgetechnique,asinglelineosteotomyisperformedrespectingalateralhingeandaprogressiveopeningisrealizeduntiltheplannedwedgeanddegreeofcorrectionarereached.Thesiteisthenfixedwithaplateandmightbefilledwithabonegraft.Thistechniquepreservesthebonestock,butitaffectsthepositionofthepatellaanditcarriesthedisadvantageofapossiblenonunion.Besides,theopen-wedgetechniquemightbeperformedinmultipleplanes:biplanarosteotomiesareperformedwhenanadditionalcutismadeattheanteriorthirdofthetibiabehindtheanteriortibialtubercle(ATT)atabout110°ofthehorizontalosteotomy.Withthismethod,thetibiaispreventedfromrotatingaroundtheverticalaxisanditcreatesananteriorbuttressagainstsagittalmovements.Moreover,thisresultsinahighersurfaceofbonecontact,enhancingthepossibilityofagoodandrapidconsolidation.Table2Advantagesanddisadvantagesofopening-wedgeandclosing-wedgePTO.Opening-wedgeosteotomyClosing-wedgeosteotomyAdvantagesAccurateprocedure,precisedeformitycorrectionFasterconsolidationPreservationofproximaltibiofibularanatomyNobonegraftrequiredAvoidperonealnervedamagePreservationofproximaltibiabonestockEasierconversiontoTKRMultiplanarcorrectionNolegshorteningDisadvantagesUsuallyrequirebonegraftingDisruptionofproximaltibiofibularanatomySlowerconsolidationReducedproximaltibialbonestockNonunionriskDifficulttoadjustpreciselydeformitycorrectionChangesintibialslopeandpatellaheightPeronealnervedamageriskShorteningofthelegMonoplanarcorrectionIntheplanningofaPTO,patellarheightandeventualleglengthdiscrepancyshouldbecriticallydetermined,sincethebiplanaropen-wedgetechniqueresultsinadistalizationofthepatellaandanincreaseintheleglength.Weknowthatthepatellaheightwilldecreaseapproximately2mmper10°ofvalguscorrection(2).OnesolutionwouldbetoorienttheobliqueosteotomycutdistallytotheATT,andfixitwithoneortwobicorticalscrews.Thismaybeindicatedinpatientsrequiringacorrectionofmorethan10°and/orinpatientswithapreexistingpatellainfera.Regardingleglengthdiscrepancy,aclose-wedgeosteotomymaybebetterindicatedinpatientswithadiscrepancyofmorethan1.5cminfavoroftheoperatedleg.Triplanarosteotomymightbesuitableforpatientswithaposteriorcruciateligament(PCL)injuryassociatedwithavarusknee,withatibialslopeoflessthan9°(5).Indeed,anincreaseofthetibialslopemayeasilybeperformedconcomitantlytoanopen-wedgePTO.Likewise,anACL-deficientkneewithavarusdeformityandhightibialslope(9–12°)maybenefitfromaclose-wedgeosteotomysincethetibialslopetendstodecreaseinthistechnique(6).IncaseofacombinedACL + PTOprocedure,theosteotomymustbeperformedfirst,positioningoftheanteriorproximalscrewsshouldbedoneafterdrillingofthetibialtunnelandpassageofthegraft.However,it’sstillunclearifanadvantageinacombinedHTO + ACLreconstructionexists,comparedtoHTOalone(7).Finally,thepostoperativedegreeofcorrectionisstillamatterofdebate.Intherecentliterature,anindividualizedpostoperativecorrectionissuggested,ratherthanacorrectiontotheFujisawaarea(62–68%ofthelateraltibiawidth).Forexample,someauthorsproposedacorrectionto55%tibialwidth(1.7–2°mechanicalvalgus)(8)tobalancemedialandlateralloadingstress,whileotherssuggestahypercorrectiontoamechanicalaxisof4.5°invalgus,tobetterdistributestressamongthetwocompartments(9).Theauthorsusuallypursueatailor-madecorrection,inpatientswithosteoarthrosis,thepostoperativeaxisshouldbeintheFujisawaarea,whileforPTOassociatedwithcartilageormeniscusprocedures,weusuallyplanforamechanicalaxisof0–3°valgus.Thereisstillalargeopportunityforimprovementinosteotomiesincludingfurtherdevelopmentinnavigationsystems,especiallytonavigatethetibialslope,controlthejointlineobliquityandtheprecisionofthecorrectionindoublelevelosteotomies.Preoperative3D-CTscanplanningresultinginindividualizedcuttingblocksandcustomizedplatesmayimprovethereliabilityandtheprecisionoftheosteotomy,aswellasfacilitateitsrealization.Thosetechniquesarestillindevelopmentandtheirperformancesarestillunderinvestigation.Distalfemurosteotomies(DFO)Distalfemurosteotomy(DFO)isawell-knownsurgicalprocedureusedtocorrectthevalgusdeformity,thatmightbealsopost-traumaticorduetogrowthdisorders,inyoungactivepatientswithlateralcompartmentarthrosisorcartilagedamage.Inthiscase,thegoalsaretounloadthelateralcompartmentinordertodecreasepainandosteoarthritisprogression.Valgusdeformityislessfrequentthanvarus,sonotsomanypapersarepublishedonDFOpostoperativeoutcomes.However,surgeonsmustkeepinmindthatvalgusmalalignmentisnotonlyrepresentedbyafemoral-baseddeformity.Infact,recentstudieshighlightedthatthemalalignmentmaybeduetoatibial-basedoracombinedfemoralandtibialdeformity(10).IndicationsIdealcandidateforaDFOprocedureshouldbeyoungerthan65years,active,withavalgusdeformity,affectedbyisolatedlateralcompartmentosteoarthritis.Candidatesshouldhaveapreoperativeextension/flexion0–120°rangeofmotionwithanormalBMI.PoorpostoperativeoutcomesarerelatedtoBMI＞30,nicotineabuseandseverepatellofemoralosteoarthritis,whichsomeauthorsconsiderarelativecontraindicationfortheDFOprocedure.Othercontraindicationstothisprocedureareseverelateralcompartmentinvolvement(Ahlback＞III),medialcompartmentortricompartimentalosteoarthritis,aswellaspoorlycontrolledchronicinflammatoryarthritisandosteoporosis.Valgusdeformitygreaterthan20°areconsideredacontraindicationtoDFOasitcanbeassociatedwithsevereligamentousinstability(11).DFOcanbeindicatedinpatientsaffectedbychondrallesionsofthelateralcompartmentinavalgusknee,inordertoachievecorrectionofthemalalignmentandprotectionofthechondralrepair.Cartilagetreatmentcanbecombinedatthesametimeasthecorrectionofthedeformity,whereasdeformitiesduetogrowthdisordersorpost-traumaticmustbeaddressed,ifpossible,beforetheonsetofthearthrosis.DFOmightalsobebeneficialinyoung,sportivepatients,evenwithinitialstageofosteoarthrosis,whoneedaconcomitantlateralmeniscusallografttransplantation,inordertooffloadthelateralcompartmentandthefreshlyimplantedallograft.Incaseofligamentousinstability,DFOcanbeperformedasastandaloneprocedureorcombinedwithaconcomitantorstagedligamentreconstruction.Forexample,somestudieshaveanalyzedtheoutcomesafterlateralopen-wedgeDFOaloneperformedonvalguskneewithMCLdeficiency,showingadecreaseofthemedialopeningat30°offlexion.Thiscouldbeconsideredinlow-demandpatients(12).TechniquesDFOcanbeperformedasalateralopen-wedgetechniqueorasamedialclose-wedgeone(Fig.2).Inthefirstone,osteotomyisperformedwithaninclinationof20°fromtwotothreefingersproximaltolateralepicondyleaimingatapointfewmillimetersproximaltothemedialepicondyle,inordertoremoveabonywedgeofpredefineddimensionandgentlyopeningthesiteinvarusuntilthedesireddegreeofcorrectionisreached.Thesiteisthenfixedwithplatesandmightbefilledwithbonegraft.Themedialhingeshouldbepreservedbyadvancingtheoscillatingsawnomorethan1cmawayfromthemedialcortex,asitismorefragileandpronetofracture,resultingincollapsingoftheosteotomysiteandgreatdifficultyincontrollingtherotationalstability(13).Thisprocedureistechnicallymoredemanding,butallowsanaccuratecorrectionandtherestorationofthefemoralheight,especiallyinthosepatientsrequiringmildtolargecorrection.Ontheotherhand,thedisadvantagesofthisprocedurearerepresentedbythedangerofhingefractureandtheincidenceofdelayedunionornonunionoftheosteotomysite.Astudyanalyzedthebiomechanicsresultofthefemoralosteotomies,highlightinghowthelateralopen-wedgetechniqueresultedininferiorstabilityandinlowerstiffnesscomparedtotheclose-wedgeone.Therefore,abonegraftorsubstituteshouldbemandatoryinordertoenhancethebiologicalhealing.Intheclose-wedgetechnique,parallelpinsarethendriveninthecortexfromthemedialsupracondylarareatothelateralcondyleandtheproximalpartoftheosteotomyisperformedthroughtheantero-posteriorcortex,preservingthelateralone.Thebonewedgeisremovedandtheosteotomysiteisclosedandfixed,compressingthemedialcortex.Theconventionalsingleplanosteotomyhasbeenreplacedbythebiplanartechnique,inwhichtheosteotomiesareperformedintheposteriorthree-quartersofthefemurandcompletedwithanascendingcutperformedontheanteriorsurfaceofthefemur.Thistechniqueallowsforamoredistalpositioningofthelateralhingepoint,awidercontactofsurfaceandmoreaccuratecontroloftherotationalstability.Finally,itenhancesbiologicalbonehealing.Furthermore,studiesreportednolossofcorrectioninthefollow-upexaminationandlowincidenceofnonunion.However,thereisstillanactivedebateabouttheindicationtoopen-versusclose-wedgesurgicaltechniques.Arecentsystematicreview(14)showedsimilaroutcomesforthetwoprocedures,withnodifferenceinradiographiccorrection,bonyhealingorpatient-reportedoutcomes.Figure2Medialopen-wedgedistalfemoralosteotomy.Finally,postoperativecorrectionisstillamatterofdebate,asmanyauthorsrecommendacorrectiontotheneutralalignment(50%WBL),butrecentbiomechanicsstudies(15)showedthata5°ofovercorrectionrestoresnear-normalcontactpressureandcontactareainthelateralcompartment.Inourexperience,insingleDFO,weusuallyfavorbiplanarmedialclosing-wedgeosteotomy,unlessthereisahypoplasiaofthelateralcondyle.Inthissituation,werathergoforalateralopening-wedgeosteotomy.Bothosteotomiesarefixedwitharigidplateandlockedscrews.Doublelevelosteotomies（DLO）Generally,PTOaloneisthepreferredsurgicalprocedureforvarusdeformitycorrection,andgoodoutcomesarereportedintheliterature,butvarusmalalignmentmightbetheresultofadeformitylocatedonthetibia,thefemuroracombinationofthetwo.Nowadays,moreawarenesshasbeenraisedinaddressingsurgery,especiallyinpatientswithseverevarusdeformity.Infact,itwasreportedthatisolatedPTOinseverevarusdeformity,whichrequirealargecorrection,mightresultinanexcessivelateralobliquityofthejointline(JLO)(Fig.3),creatinganewdeformity(16).Thismayleadtoincreasedshearcontactoncartilages,potentialfemoralsubluxationandsubsequentdifficultiesintotalkneereplacementconversion.Inthissetting,doublelevelosteotomy(DLO)becameverypopularasitgatherstheadvantagestounloadtheaffectedcompartmentwithoutcausingnon-physiologicjointlineangles.Still,thepatellofemoralinvolvementisamatterofdiscussionasthereisalackofinformationaboutchangesthatDLOcausesonpatellaheightandpatellofemoralalignment.Figure3Posteriortibialslope.IndicationsTheidealcandidatesforaDLOarepatientsaffectedbyavarusaxialdeformity,whichcorrectionatonelevel,wouldcreateanon-physiologicaldeviationofthejointline.IfduringpreoperativePTOplanningtheMechanicalmedialproximaltibialangle(mMPTA)ismorethan95°,lateraldistalfemoralangle＞90°andtheplannedbonewedgesizeis＞15mm,thenDLOshouldbeconsidered.ThoseindicationscomefromstudiesthathighlightedhowapostoperativemMPTAgreaterthan95°leadstoinferiorclinicaloutcomes,increasedmedialjointstressandhigherfailurerates.OthergoodcandidatesarepatientswithdeformitybothinthefemurandinthetibiawithmMPTA＜85°andmechanicallateraldistalfemoralangle＞90°,affectedbymedialcompartmentosteoarthritis(16).Furthermore,patientswithpre-existentjointlineobliquity,suchasapatientwhounderwentepiphysiodesisorpreviousosteotomy,couldbeaddressedwiththisprocedure.TechniquesInordertotreatavarusdeformitywithaDLO,alateralclose-wedgefemoralosteotomyhastobecombinedwithamedialopen-wedgetibialosteotomy.Thesurgicaltechniquesperformedarethesameasaforementionedforopen-wedgePTOandclosed-wedgeDFO.SurgeryshouldstartfromtheDFOclose-wedgeprocedure,inordertosaveabonywedgethatcouldbeusedasafillinggraftinthePTOopen-wedgeprocedure,andthusenhancebonehealing.Afurtherpotentialadvantageofperformingtheopen-wedgeasasecondstepisthatsurgeonscanperformarefinedintraoperativeadjustmentofthelegaxis(17).ThisispossiblebycorrectingthedeformityonthefemoralsideinordertoreachahorizontalJLOandthenaddressingthevarusdeformitywiththetibialosteotomy.Thecombinationofclose-wedgefemoralosteotomyandopen-wedgetibialosteotomypreventsleglengthdiscrepancyaswell.Nowadays,noconsensushasbeenreachedovertheidealpostoperativealignmentandjointlineorientation.SomeauthorsperformaslightovercorrectionwithameanmTFApostoperativeof0.8°,whileothersaimfora2–3°ofmTFA(18).Inourexperience,wesuggestcorrectingthedeformitypresentonthedistalfemur,followedbythecorrectionoftheconstitutionalvarus+3to5°accordingtotheglobalcorrectiontobeplanned.Slope-changingosteotomies（SCO）ACLorPCLreconstructionmightfailduetoextrinsicfactors,relatedtosurgicaltechniqueerrorsorinadequaterehabilitation,andintrinsicfactorsrelatedtopatientanatomyandligamentstructures.SurgeonsmustidentifyandaddressthecausesofACLorPCLprimaryreconstructionfailureinordertoplanasuccessfulrevisionsurgery.Amongthesefactors,particularattentionmustbepaidtotheposteriortibialslope(PTS).StudiesunderlinedthatanexcessivePTSislikelytoincreasetheanteriortranslationofthetibiawhileweightbearing,causinganteriorinstabilityandthereforeincreasingthestresstensileforcesontheACLgraft.Intheliterature,someauthorshaveshownthatpatientswithaPTSgreaterthan12°hadfivetimeshigheroddsofACLinjuryanda59%incidenceofgraftre-tear(19).Ontheotherhand,areducedPTSincreasestheposteriortibialtranslationinbothflexionandextension,leadingagaintohigh-stresstensileforcesacrossnativeorreconstructedPCLthatmightresultingraftfailure.AdecreasedPTShasbeenidentifiedasthepredominantcauseofgenurecurvatumaswell.IndicationsAnteriorclosed-wedgeosteotomy(ACWO)canbeperformedinpatientswithrecurrentACLreconstructionfailuresassociatedwithaPTSgreaterthan12°.Contraindicationstothisprocedureareseveremalalignmentofmorethan10°varus,morethan10°kneehyperextensionandevidenceofgradeIVKellgren–Lawrenceosteoarthritis.Relativecontraindicationsinvolveobesepatientsandheavysmokers.Anterioropen-wedgeosteotomy(AOWO)canbeperformedinpatientswithsymptomaticPCLdeficiencyandanevidentsagittaltibialmalalignmentcausedbydecreasedPTS.Arecentarticle(20)suggestsconsideringAOWOinpatientsundergoingPCLreconstructionwithaPTS＜5°andaPTS＜7°inpatientsundergoingPCLrevision.Inthecaseofgenurecurvatum,Dejouretal.(21)statedthatanabsoluteindicationisrepresentedbythecombinationofbonyandsofttissuerecurvatumwhichmightbeaddressedbyosteotomyaloneorbysofttissuereconstructiveprocedures.AOWOmightbeindicatediftherecurvatumisduetoadecreasedPTSandifthepatientcomplainsofpainorinstability,anditcanonlybeperformedinskeletallymatureindividuals.AOWOiscontraindicatedinpatientswithdeformitysecondarytopoliomyelitis,asthiswouldcreatemorekneeinstability,andinpatientswithpuresofttissuerecurvatum.TechniquesACWOisasurgicalprocedureinwhichananteriorbonywedgeisremovedbythetibiainordertodecreasethePTSbyclosingtheosteotomysite.Itmightbeperformedwithdifferenttechniquesanddifferentosteotomypositions,below,aboveoratthesameleveloftheATT.Dejouretal.andWalkeretal.(22)describedanosteotomytechniqueabovetheATT,startingfromthesuperiormarginofpatellartendonandsecuringtheosteotomysitewithtwostaples.Thistechniqueshouldnotbeperformedinapatientwithpatellaalta,asitmightworsenthepatellatrackingbiomechanics.Sonnery-Cottetetal.firstdescribedanosteotomytechniquebelowtheATT,involvinga6-cmATTosteotomyandsubsequentsynthesiswithtwocorticalscrews(23),whileHeesandPetersenmodifiedthetechnique,avoidingtheATTdetachment(24).Alltechniquesrequireagoodexposureonbothsidesofthetibiaandperfectsymmetryintheclosing-wedgeosteotomy,whichmaybecheckedbyensuringthattwoguidewireslieparalleltothejointline.Thetwoconvergingguidewires,whichdefinetheosteotomylimits,shouldbedrivenaimingattheposteriorcortex,just1cmbelowthePCLtibialinsertion,withoutviolatingtheposteriorhinge.IfacombinationofACWOandACLrevisionisplanned,theautograftharvestingmustbeperformedasafirststepandthefixationsystemshouldnotinterferewiththecreationofthetibialtunnel.Studies(24)demonstratedgoodoutcomeswithpostoperativePTSlessthan＜10°,authorssuggestthatpostoperativecorrectionshouldbeideallyinthe6–8°range.InAOWO,ananteriortibialbonylineiscutandprogressivelyopenedinordertoachieveanincreasedPTS.AsACWO,osteotomiesmightbeperformedabove,beloworatthesamelevelastheATT(25).ThemostusedsurgicaltechniqueistheonedescribedbyLecuireetal.(26)inwhichaprior6–8cmtangentialATTosteotomyisperformed,followedbythecutoftheosteotomylineundertheATT,thentheopeningofthewedgeattheplannedcorrectionismade.TheguidepinsmustbepositionedatthetibialinsertionofthePCLandtheposteriorhingeshouldnotbedamaged.Surgeonsmustpayattentiontobeperfectlysymmetricalintheopeningofthewedge,theosteotomysitecanbefilledwithbonygraftandtheATTshouldbeproximalizedbasedonthecorrectionachievedtoavoidapatellainfera.PosteriorkneelaxityshouldbethenreassessedafterthefixationinordertoaddresstheneedforPCLreconstructionornot.Anteriortibialtubercleosteotomies（ATTO）TranspositionoftheATTisperformedaloneorincombinationwithothersurgicalproceduresinawiderangeofpatellofemoralpathologies,suchaspatellarinstability,osteoarthritisandoverloadsyndromes.Patellofemoraljointkinematicsandstabilitydependonbothsofttissuerestraintsandbonemorphology.Forexample,importantvarusorvalgusdeformitywillaffectthetrackingandthepatellarstresscontactarea,leading,forexample,tooverloadsyndromes.IndicationsInthecaseofpatellainstability,surgicalproceduresareindicatedwhentheinstabilitybecomespersistentandthepatienthassufferedfromtwotothreeepisodesofdislocation.Inthissetting,thesurgeonsmustassessandrecognizeallthepotentialfactorsthatcausedorfacilitatedthedislocation.AmongstthefourriskfactorsdescribedbyDejouretal.(27),abnormaltibialtubercle-trochleargrooveindex(TT-TG)shouldbesystematicallyappreciatedandcorrectedthroughanosteotomyoftheATT.IncreaseTT-TGmightalsobecausedbyexcessivetibialrotation,femoralanteversion,valgusandrecurvatumdeformity.ItisthereforeimportanttodefinethegreaterTT-TGinareliablemannertopreventthecreationofaniatrogenicpainfuloverloadofthemedialcompartmentconsecutivetotheosteotomy.OsteotomyoftheATTmightalsobehelpfulinasymmetricalpatellofemoralosteoarthritiswithanabnormalTT-TG.Thisosteotomyisusuallyassociatedwithafacetectomyofthelateralportionofthepatella.TechniquesIftheTT-TGvalueis＞20mmmeasuredonCTor＞13mmonMRI,atibialtuberclemedializationissuggested,asitdecreasesthevalgusforceexertedbytheextensormechanism.TheaimshouldbetherestorationofaTT-TGbetween10and15mm.Inthecaseofpatellaalta(Caton-Deschamps＞1.2)withashortpatellartendon,atibialtubercledistalizationisadvised,aimingtorestorethenormalvalueandtoobtainabetterpatellartracking.Inthecaseofahypoplasticmedialfacetofthetrochlea(typeC),atibialtubercledistalizationof5mmandanoptionalmedializationcouldbeperformedtoenhancethepatellartracking.SurgeonsmusttakeintoaccountthatduringATTdistalizationof1cm,asubsequent4mmmedializationwilloccur.Lateralretinaculumlengtheningshouldbeperformedonlyifthetightnessoflateralrestraintscausesanegativepatellartilttest.Medialpatellofemoralligament(MPFL)reconstructionshouldbefrequentlyaddedtoreducethefailurerateoftheaforementionedprocedures.ConclusionsOsteotomiesaroundthekneerepresentahighlyreliableandreproducingtreatmentoptionforkneepathologywithverysuccessfulpostoperativeoutcomes.Surgeonsmustbeawareoftheappropriateindications,accurateplanninganduseofreproduciblesurgicaltechniques.Furtherdevelopmentinsoftware,3D-basedtechnologyandnavigationsystemsmightbepromisinginordertoimprovetheaccuracyofplanningandintraoperativecorrection.

骨性关节炎X线诊断标准Kellgren＆Lawrence（1957年）分级法_骨关节病的放射学评估（1957）Radiologicalassessmentofosteo-arthrosisKELLGRENJH,LAWRENCEJS.Radiologicalassessmentofosteo-arthrosis[J].AnnRheumDis,1957,16(4):494-502.转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/13498604/转载文章的原链接2：https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1006995/骨性关节炎放射X线诊断标准Kellgren＆Lawrence（1957年）分级法：在流行病学的研究中，大多数学者仍然使用Kellgren＆Lawrence的放射诊断标准。该标准将骨关节炎分为五级：0级正常（X线无异常）；Ⅰ级可能有骨赘（疑似骨赘形成）（轻微骨赘），关节间隙可疑变窄；Ⅱ级有明显的骨赘，（未累及关节间隙）关节间隙轻度变窄；Ⅲ级中等量骨赘，关节间隙变窄较明显（关节间隙中度狭窄）（关节间隙明显狭窄），软骨下骨质轻度硬化改变，范围较小；Ⅳ级大量骨赘形成，可波及软骨面，关节间隙明显变窄（甚至消失），（软骨下骨）硬化改变极为明显，关节肥大及明显畸形。这一标准属于放射学评价，而且是对骨赘的作用强调的较多，此标准仍存在较大的争议。本人认为这一标准太笼统，没有量化，临床实践中难于把握，每个临床医生之间的结果没有可比性，不便于交流和指导科研和临床工作。Figure1.OAStages(KellgrenandLawrence,1957)（a）Grade0:Physiologicaljoint.（b）GradeI:SubtleJSNinthemedialcompartmentwithosteophyticlipping.（c）GradeII:DefiniteJSNinthemedialcompartment.（d）GradeIII:DefiniteJSNinthemedialcompartmentandsclerosisofthesubchondralbone.（e）GradeIV:JSNwithabone-on-bonephenomenonanddeformityoftheedialtibialplateauaswellasthemedialfemoralcondyle.Fig.1Osteo-arthrosisofdistalinterphalangealjoint.Fig.2Osteo-arthrosisofproximalinterphalangealjointFig.3Osteo-arthrosisofmetacarpophalangealjoint.Fig.4Osteo-arthrosisoffirstcarpometacarpaljointFig.5Osteo-arthrosisofwristFig.6Osteo-arthrosisofcervicalspineFig.7Osteo-arthrosisofhipFig.8Osteo-arthrosisofknee

膝关节骨性关节炎阶梯化治疗的新进展(2023)骨性关节炎（osteoarthritis，OA）是一种严重影响患者生活质量的关节退行性疾病，而膝关节骨性关节炎（kneeosteoarthritis，KOA）在临床最常见，主要表现为膝关节疼痛和活动受限。膝关节骨性关节炎是发病率最高、临床最常见、病程长、阶梯性明显、对个体和社会损害最大的骨关节炎之一。由于种种原因，目前我国各地区、各级医院骨科诊疗水平发展不均衡，关节疾病的诊疗水平参差不齐，对膝关节骨性关节炎的诊疗缺乏系统性的培训、全面深入的认识，难以对膝关节骨性关节炎患者严重程度进行恰当判断，易导致不适合治疗或诊疗延误。有鉴于此，查阅国内外最新文献，聚焦对膝关节骨性关节炎阶梯化治疗：基础治疗、药物治疗、修复性治疗和重建治疗四个层次，经过充分细致、广泛深入、独立客观、科学循证的文献分析，总结形成膝关节骨性关节炎阶梯化治疗的图文并茂、容易理解掌握的新进展。以期本新进展为医务人员对膝关节骨性关节炎阶梯化的治疗工作，提供科学、规范、有效的参考。新进展的全文请见PDF文档。

后外侧小切口辅助Bernese髋臼周围截骨术治疗症状性髋关节发育不良(2022)TreatmentofsymptomatichipdysplasiabyposterolateralsmallincisionassistedBerneseperiacetabularosteotomy LiC,ZhangX,MengX,PuL,ChenH,SuY,BuP,XuY,LiuT.TreatmentofsymptomatichipdysplasiabyposterolateralsmallincisionassistedBerneseperiacetabularosteotomy[J].BMCSurg,2022,22(1):217. 转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/35668407/转载文章的原链接2：https://pmc.ncbi.nlm.nih.gov/articles/PMC9169320/ AbstractBackgroundForperiacetabularosteotomy,traditionalapproachesusuallyhavealonglearningcurve.Weaimedtoevaluatethepostoperativeresultsandcomplicationsofperiacetabularosteotomyunderanewdouble-incisionapproach. MethodsTherecordsof58consecutivepatients(65hips)whounderwentperiacetabularosteotomyusingthenewapproachwereretrospectivelyreviewedandevaluated.Therewere52womenand6menwithameanageof28.1yearsatthetimeofsurgery. ResultsTheaveragefollow-upperiodwas35.2months,duringwhichnopatientswereconvertedtototalhiparthroplasty.Complicationsincluded6hips(9.2%)withnervedysesthesiasand1hip(1.5%)withdelayedwoundhealing.Themeanoperativetimeandintraoperativebloodlosswere88.6minand402.8ml,respectively.ThemeanmodifiedHarrishipscorehadimprovedfrom72.2pointspreoperativelyto91.3pointsatthelastfollow-up.Fifty-fivepatients(62hips,95.4%)weresatisfiedtotheiroutcomes,andgoodpreoperativefunctionalscorewasassociatedwithasatisfactoryoutcome.Furthermore,theaveragelateralcenter–edgeangle,anteriorcenter–edgeangleandacetabularindexanglewerecorrectedwellaftersurgery. ConclusionPeriacetabularosteotomyusingmodifiedSmith-PetersenorBikiniapproachwithposterolateralassistedsmallincisioncanbeperformedsafelyandwithsatisfactoryresults.Inaddition,thistechniqueshortensthelearningcurve,andreducestheoperatingcomplexity,especiallyforbeginner.髋臼周围截骨采用改良的Smith-Petersen或Bikini入路，后外侧辅助小切口可以安全且效果满意。此外，该技术缩短了学习曲线，并降低了操作的复杂性，特别是对于初学者。 Keywords:Developmentaldysplasiaofthehip,Periacetabularosteotomy,Double-incisionapproach,Learningcurve BackgroundAcetabulardysplasiamayleadtoearlydevelopmentofjointdisease[1,2].Asyet,theexactmechanismsarenotfullyunderstood.Becausethefemoralheadandacetabulumofhipdysplasiadonotmatchwellasaconcentriccircle,theabnormalstressconcentrationcanleadtoexcessivestressinthelocalcartilage.Thisisacommoncauseofosteoarthritisthateventuallyrequirestotalhiparthroplasty(THA)[3,4].Inordertoimprovethematchingratebetweenthefemoralheadandtheacetabulum,preventtheoccurrenceofosteoarthritisordelaythefurtherdegenerationofarticularcartilage,avarietyofpelvicosteotomyhavebeendesignedtocorrecttheabnormalacetabulum,includingsingleinnominateosteotomy,doubleosteotomyandtripleosteotomy[5,6].TheBerneseperiacetabularosteotomy(PAO)describedbyGanzetal.inthe1980swasanovelandcommonlyusedsurgicaltechniquetoreorienttheacetabuluminadolescentsandadults[1,4,7–10].1.IsaksenKF,RoscherEK,IversenKS,EitzenI,Clarke-JenssenJ,NordslettenL,MadsenJE.Preoperativeincipientosteoarthritispredictsfailureafterperiacetabularosteotomy:69hipsoperatedthroughtheanteriorintrapelvicapproach.HipInt.2019;29(5):516–26.4.AliM,MalviyaA.Complicationsandoutcomeafterperiacetabularosteotomy-influenceofsurgicalapproach.HipInt.2020;30(1):4–157.GanzR,KlaueK,VinhTS,MastJW.Anewperiacetabularosteotomyforthetreatmentofhipdysplasias.Techniqueandpreliminaryresults.ClinOrthopaedRelatedRes.1988;232:26–36.8.KimHT,WooSH,LeeJS,CheonSJ.AdualanteroposteriorapproachtotheBerneseperiacetabularosteotomy.JBoneJtSurgBr.2009;91(7):877–82.9.BiedermannR,DonnanL,GabrielA,WachterR,KrismerM,BehenskyH.Complicationsandpatientsatisfactionafterperiacetabularpelvicosteotomy.IntOrthop.2008;32(5):611–7.10.ImaiH,KamadaT,MiyawakiJ,MaruishiA,MashimaN,MiuraH.Outcomesofcomputer-assistedperi-acetabularosteotomycom-paredwithconventionalosteotomyinhipdysplasia.IntOrthop.2020;44(6):1055–61 ThePAOtechniquepreservestheposteriorcolumnintactwhilepreservingbloodsupplysimultaneously,allowingforlargerotationadjustmentsinmultipleplanesandmaintainingpelviccontinuity[6,7].Somestudieshaveshownthatthe10-and20-yearsurvivalrateforthenativehipjointsaftertheBernesePAOsurgeryareabout80–86%and60%,retrospectively[11,12].However,there’swideagreementthattheBerneseosteotomysurgeryistechnicallydifficultwithalonglearningcurve.InordertoperformPAOsafelywithlesscomplications,severalsurgicalapproaches(modifiedSmith-Petersen(S-P),ilio-inguinal,directanterior,trans-trochanteric,anddoubleapproaches)havebeentriedovertheyears[4,6].Obviously,anysuchapproachesshouldnotcompromisetheadequacyofcorrection,functionaloutcomeandcomplicationrate.SomestudiessuggestedthatthemodifiedS-Papproachwasthesafestintermsofvesselandnerveprotectionandcomplicationrate[6,13,14].However,whenthemodifiedS-Papproachwasusedforacetabularosteotomy,somestudieshaveshownthatthefinalfunctionresultsareaffectedbyinadequatevisualfiledexposureandsofttissuerelease[8,15].Becauseoftheblindnessandcomplexityoftheanatomy,thePAOosteotomywiththeseapproachesremainsamajorchallenge,especiallyforbeginner.Thepurposeofthepresentstudywastoreportwhetherourdouble-incisionapproachwasassafeandachievesthesamemorphologicalcorrectionsasthesinglemodifiedS-PorBikiniapproachthatquotedintheliterature.Inaddition,weassessedtheeffectofpossiblepreoperativeriskfactorsonunsatisfactoryoutcomesaftersurgery.6.BernsteinP,ThielemannF,GüntherKP.Amodificationofperiacetabularosteotomyusingatwo-incisionapproach.OpenOrthopaedJ.2007;1:13–8. MethodsAretrospectivestudyincludingpatientsunderwenttheBernesePAOsurgerywasperformedfromFebruary1,2016toJune30,2019.ThestudywasapprovedbytheEthicsCommitteeonHumanResearchofthe920thHospitalofJointLogisticsSupportForceofChinesePeople’sLiberationArmy,andwritteninformedconsentwasobtainedfromtheparticipants.TheTönnisclassificationofhiposteoarthritis[16,17]wasusedtogradeosteoarthritis,andtheHartofilakidisclassificationsystem[18,19]wasusedtoassessthedysplastichip.Theindicationsforacetabulumosteotomyincludesymptomatichipdysplasiathatpersistsformorethan6monthsafternonsurgicaltreatmentfailure,center–edgeangleofWiberg(LCEangle) < 25°,acetabularindex(AI) > 10°,Tönnisgrade0–1,Y-typeepiphysealcartilageclosure,andyoungerthan50yearsofage[14,20,21].Furthermore,theinclusioncriteriaincluded:(I)acetabularreorientationsurgerywiththeuseofBernesePAO,(II)usingthemodifiedS-PorBikiniapproachwithposterolateralassistedincision.Theexclusioncriteriaincluded:(I)patientwhohadundergonepreviousipsilateralpelvicosteotomyorsufferedfromneuromusculardisease,(II)patientwithosteo-chondroplasty,(III)patientwithahistoryofpathologicalbonedisease,and(IV)patientwithincompletemedicalrecords.Thefirst10patients(10hips)inourcurrentstudywereexcludedbecausethesesurgerieswereperformedwiththehelpofotherspecialists.Finally,ourpresentretrospectivestudyinvolved60patients(67hips)whomettheinclusioncriteria,amongwhich2patients(2hips)werelosttofollow-upbecauseofrefusingtotrackontime.Theclinicalandradiographicdata(Figs.1and2)abouttheincludedpatientswerecollectedunderthesamecriteria.Demographiccharacteristicsoftheincludedpatientswerenotedfromthemedicalrecords,andshowninTable1.  Fig.1.Preoperativeradiographandpost-operativecorrectionofa22yearsoldwomanwithbilateralhipdysplasia.ShewastreatedbyBernesePAOusingthedouble-incisionapproach.A,BPreoperativeradiographsofpelvis,showingbilateralacetabulardysplasia.C,DPostoperativeanteroposteriorpelvicradiographandfalse-profileradiographofthelefthipat2months.E,FPreoperativeradiographsoftherighthip.G,HPostoperativeanteroposteriorpelvicradiographandfalse-profileradiographat1year(lefthip)and6months(righthip)  Fig.2.Preoperativeradiographsandpost-operativecorrectionofan18yearsoldmanwithbilateralhipdysplasia.HewastreatedbyBernesePAOandfemoralderotationosteotomyunderthedouble-incisionapproach.A,BPreoperativeradiographsofthepelvis,showingbilateralacetabulardysplasia.C,DPostoperativeanteroposteriorpelvicradiographandfalse-profileradiographofthelefthipat3months.EPreoperativefalse-profileradiographsoftherighthip.F–HPostoperativeradiographsat1year(lefthip)and9months(righthip),showinggoodreconstructionofthehips  Table1.DemographicsandclinicaldataforallpatientsVariablesMean ± SD(range)No.ofpatients(hips)     58(65)Gender,n(%) Male     6(10.3) Female 52(89.7)Age(years)   28.1 ± 8.35(11–49)BMI(kg/m2)  22.0 ± 3.02(17.4–30.4)Side(hips,%) Left      30(46.2) Right    35(53.8)PreoperativeTönnisgrade(hips,%)      Grade0–1    65(100.0)Hartofilakidistype(hips,%)  TypeΙ   65(100.0)Durationofsurgery(min)     88.6 ± 17.91(65–215)Intraoperativebloodloss(ml)402.8 ± 87.28(260–900)Satisfactionofoutcomes(hips,%) Satisfactory  62(95.4) Unsatisfactory      3(4.6)Follow-up(months)       35.2 ± 10.61(18.0–56.0)SDstandarddeviation,BMIbody-massindex SurgicaltechniqueThesurgicalpositionislateralpositionfirstandthensupineposition(Fig.3),butonlyoneoperationskindisinfectionanddrapingarerequiredduringtheoperation.Beforetransferringthepatientfromthetrolleytotheoperatingtable,a30–40cmwidebedsheetwasplacedontheoperatingbedwiththesheetunderthepatient’sbuttocksforeasychangingthepositionduringoperation.Afterinductionofgeneralanesthesia,thepatientwasplacedontheoperatingbedinthelateralpositionwiththepelvislyingovertheradiolucentareaandsupportedbythedam-boards(Fig.3A,B).Inordertoobtainenoughspacefordisinfectioninthesubsequentsupineosteotomyarea,thepatient’santeriorsupportshouldnotbehigherthanthepubicsymphysis.Inaddition,toensureadequateintraoperativehipdisinfection,thedisinfectionrangeshouldreachatleastthepubicsymphysisinfront,theupperedgetotheiliacwings,andtheposteriortothemidlineofthehipabovethegreatertrochanter.  Fig.3.Theintraoperativepositionchangeandsurgicalincision.A,Banewdouble-incisionapproach,includingthemodifiedS-PorBikiniapproach(markedas“a”),one5–8cmassistedsmallincisionontherearedgeofthegreatertrochanter(markedas“b”),threesoftcushions(c)betweenthelegs,playaroleofprotectionandsupport,andplacingaclothpad(d)underthebuttockinadvance,whichhelpstodirectlypull(blackarrowdirection)andlift(bluearrowdirection)duringtheoperationtochangetheoperationposition.CAfterchangedtothesupineposition,completingthepubicramusandiliacboneosteotomythroughmodifiedS-PorBikiniincision Afterflexionofthekneeandinternalrotationoftheaffectedsidetothelateralgreatertrochantercompletelyupward,a5–8cmincisionwasmadethatwasbehindandparalleledtothebodysurfaceofthegreattrochanter(Fig.3B).Afterlayerbylayerincisionoftheskin,tensorfascialataandthebursaeassociatedwiththegreatertrochanterofthefemur,surgeoncanseetheattachmentpointofthequadratusfemoris(Fig.4A).Inthelowermarginspaceofobturatorexternusmuscle,whichliesontheupperedgeofthequadratusfemorisandabout1cmbehindthemuscleattachmentpoint,thebluntdissectionwithfingerassistancewasmadetodepthsuntiltheinferioracetabularsulcusisreached.Duringtheexposureprocess,thesciaticnervewrappedbytheyellowfatlayercanbeseen,anditshouldbeproperlyprotectedwithan“S”retractor.Stripingtheperiosteumforwardandbackwardalongtheinferioracetabulargroovewithanarrowlongperiosteumdetacher,andmoreattentionshouldbepayedtostretchtheaffectedlimbasfaraspossiblewhenstriptheperiosteumbackward.Then,usingtwoHoffmanretractorstoexposuretheosteotomyareaofischiumramus(Fig.4B).Subsequently,a1.5cmwidestraightosteotomewasusedtoperformtheischialosteotomyaccordingtothemarkedline(Fig.4B)andmaintaininganangleof10°–15°withthecoccyxpoint.Moreattentionshouldbepayedtoensurethatallthreecorticalbonesarecompletelytransectandthattheposteriorcolumnremain1–2cmosseouscontinuity(Fig.4C).Inordertosafelyandcompletelyresectthecorticalboneoftransversegrooveoftheacetabulumunderagoodview,theosteotomeshouldbeclosetotheanteriorHoffmanretractor.Whenperformingtheupperposteriorosteotomyalongthemarkedline,thesurgicalassistantshouldpayattentiontoextendtheaffectedlowerlimbstorelaxthesciaticnerve.Normally,theosteotomyoftheischialbranchcanbedonewithanosteotomeofthiswidthfortwotimes.Whentheischialosteotomyiscompleted,theincisionissuturedlayerbylayer.  Fig.4.Schematicdiagramofischialosteotomy.AExposetheposterolateralassistedincision,andonlythequadratusfemoris,theinferiorgemellus,andtheobturatorexternalmusclesneedtobeexposed.BEnterintotheintermuscularspaceoftheuppermarginofquadratusfemoris,revealingthesiteofischialbranchosteotomy,thatistheinferioracetabularsulcus(markedas“a”),thenoneHoffmanhooks(b)wasplacedintotheobturatorforamenalongthefrontedgeoftheinferioracetabularsulcus,andanotherpointedHoffmanhooks(c)washitintoboneat1.5cmawayfromtheedgeoftheposteriorcolumn,thesciaticnerve(blackarrow)wasprotectedby“S”hookandextendingtheaffectedlowerlimbssimultaneously.C1–1,1–2,and1–3representthecortexoftheinferioracetabularsulcus,lateralandmedialcortexoftheloweredgeoftheacetabulum,respectively  Subsequently,withthehelpofitinerantnurseandanesthetist,thepatientwaschangedfromalateralpositiontoasupineposition(Fig.3C).Theitinerantnurseremovestherestraintbeltsofpatient’slimbsandtheanteroposteriordam-boardfirstly,thenpullsthepreparedsheetinparallelupwardstoconvertthepositionofpatient.Duetothechangeinpatient’sposition,therelativecontaminatedareaofthesterilesheetontheunaffectedsidewouldriseslightly.Atthistime,itisrecommendedtocoverthesterilesheetontheunaffectedsideagain.AtraditionalpelvicosteotomysurgerywasthenperformedasdescribedusingamodifiedS-PorBikiniapproach[6–8].Theinitialskinincisionisabout10cmlength,andtheincisioncanbeextendedlaterdependingonthesurgicalexposure(Fig.5A).Theskinandsubcutaneousfasciaweredissectedandthelateralfemoralcutaneousnerve(LFCN)waspulledinwardwithoutintentionalseparation,thenanosteotomyoftheanteriorsuperioriliacspinewasperformed(Fig.5B–D).Thesartoriusmuscleattachedtotheanteriorsuperioriliacspinewaspulledinwardalongwiththeosteotomyblock,graduallyexposingtheinnerplateoftheiliaccrestandthepubictuberosity.Theiliopsoastendon,femoralnerveandvesselbundletractwereprotectedandpulledinward,andthepubicwasexposedbysub-periosteumdissection.TwoHoffmanhookswereplacedinthesubpubicobturatorforamentoexposeandprotectthepubisramusforosteotomy,orthepubiccouldbeosteotomyatabout1cminsidethepubictuberosityaccordingtotheperspectiveposition(Fig.6A).Afterexposingtheiliumquadrilateral,ischialnotchandischialspinefully,theiliacandquadrilateralosteotomywerethenperformed,andthisosteotomylinewasconnectedwiththefirstacetabularinferiorsulcusosteotomyline(Fig.6B–D).Afterconfirmingthecompleteperiacetabularosteotomy,theacetabularfragmentswererotatedtoobtainpropercorrectionforaLCEanglefrom25°to35°andanAIfrom0°to5°(Fig.7A,B),togetwellcoveredofthefemoralheadwhichwereconfirmedbyC-armfluoroscopy,andtoavoidthecross-oversignontheposteriorandanteriorX-ray[1,8,22].Afterinitialfixationofthebonefragments,thehiprangeofmotionwasmeasuredandtheacetabularosteotomywasfinallyfixedwiththreestainlesssteelscrews(Fig.7C).Movetheaffectedlowerlimbagaintocheckwhetherthefixationoffragmentisstable.Theosteotomyoftheanteriorsuperioriliacspinewasreattachedwiththeuseofscrew.Afterrepeatedflushingofthewound,subcutaneoustissueandskinwereroutinelysuturedlayerbylayer.  Fig.5.AExposetheattachmentpointoftheanteriorsuperioriliacspinethroughthemodifiedS-PorBikiniapproach.B–DCuta2–3cmlengthanteriorsuperioriliacspineblock,andpullthesartoriusmuscleandthefulcrumtowardtheinside  Fig.6.Schematicdiagramofpubicandiliacosteotomy.AThepubicramusosteotomy,twoHoffmanhookswereinsertedintotheobturatorundertheperiosteumtoprotecttheosteotomysite.BMarkthepoint“a”(thesolidline)witha1.5cmstraightosteotomeattheedgeofthearcuatelineabout4cmfromtheanterioredgeoftheacetabulum.CUseaswingsawtocuttheiliumalongthedottedlineatpoint“b”tothemarkedpoint“a”.DUseadoubleshoulderosteotomealongtheloweredgeofthemarkedpoint“a”,1–1.5cmfromtheposteriorcolumn,andcutthebonefrompoint“a”topoint“c”  Fig.7.Therotationandfixationofacetabularfragments.APlacetheSchanznailbetweentheupperandloweranteriorsuperioriliacspineandholditwithaThandle.BThereductiontowelclipwasclampedatthepubicbranchosteotomyendandtheiliumosteotomyendrespectively,soastocooperatewiththeThandletocompletetherotationcoverage,includingrotateclockwisewhenlookingdownvertically(a),lifting,pressingdownandturninginversion(b).CThefragmentswerefixedwithstainlesssteelscrews(Zimmer,3.5-mmscrewdiameterand2–5cmlengthforfixationofanteriorsuperioriliacspine,4.5-mmscrewdiameterand5–13cmlengthfortheothers),triangularsupportandfixationasmuchaspossible,andfinallyfixtheboneblockofsartoriusmusclestop Aimingtoreducebloodlossandtransfusionrates,wehaveadministratedanintravenousinfusionoftranexamicacid(TXA)(25mgper1kgweight)beforesurgery.Asecond-generationcephalosporinwastransfusedatleast30minbeforeskinincisionandcontinuedlessthan24hafteroperation.Mechanicalprophylaxiswasroutinelyadministratedagainstvenousthromboembolismwiththehelpofrehabilitationtherapists.Crutch-walkingwithpartialweight-bearingwasinstitutedfrom1weekpostoperativelyto4weeks,afterthatweight-bearingastoleratedwasallowed. ClinicalandradiographicassessmentBeforeoperation,everymonthwithin3monthsafteroperation,6monthsand1yearafteroperation,andthenannuallyduringthefollow-upperiod,clinicalandradiologicalevaluationswereperformedonallpatients(Figs.1and2).Clinicalassessmentwasfocusonpatients’demographics,previousmanagement,dailyactivityandsymptomsofacetabulum.ThemodifiedHarrishipscores(mHHS)[5]andvisualanalogscale(VAS)[1,23]wereappliedandrecordedfortheclinicalandfunctionalevaluation.Trendelenburgsignwasappliedtoassessabductionstrength.Radiographicevaluationwasbasedonthestandinganteroposteriorradiographandfalse-profilesradiographofpelvis[5].Twoindependentauthorsblindlyreviewedandassessedtheradiologyresultstominimizebiasandtheinconsistentevaluation,ifitoccurs,wasresolvedthroughdiscussionandconsensuswithtwootherseniorsurgeons.Inthepresentstudy,wegradedtheresultsaccordingtothemHHSscoresandTönnisgradeoftheaffectedhiposteoarthritis[5].Weconsideredtheresultassatisfactoryoutcomeifitwasexcellentorgoodresult,andconsideredasunsatisfactoryoutcomeifitwasfairorpoorresult[5].Inaddition,wehaveevaluatedanypossiblesignificantriskfactorsassociatedwiththeunsatisfactoryoutcomes. StatisticalanalysisTheWilcoxonsigned-ranktestort-testwasusedtoanalyzedifferencebetweenpreoperativemeasurementsandthelastfollow-upvaluesofparameters.Toanalyzedifferencebetweentheratesofsatisfactoryandunsatisfactoryoutcomes,weappliedthenonparametricWilcoxonrank-sumtestforeachcontinuousvariableandappliedFisherexacttestforeachdiscretevariable.Valuesofp < 0.05wereconsideredtoindicatestatisticalsignificance.AllstatisticalanalysiswasperformedusingSPSS19.0software(SPSSInc.,Chicago,IL,USA). ResultsThemeanoperativetimeandintraoperativebloodlosswere88.6(65to215)minand402.8(260to900)ml,respectively.NopatientswereconvertedtoaTHAatthelastfollow-up.Therewasnopatientofsciaticnerveinjury,ordeep-veinthrombosis,ornonunionoftheosteotomysite.Atthetimeoflastfollow-up,therewasnoTrendelenburg-positivehipjoint,andnopatientsexperiencedinfectionafterosteotomysurgery.Twopatients(2hips,3.1%)requireapost-operativeallogenicbloodtransfusion.Sixpatients(6hips,9.2%)hadhypoesthesiaintheLFCNdistribution,andtwopatients(2hips,3.1%)hadnoremissionofthissymptomatthelastfollow-up.Delayedwoundhealing(over2weeks)wasoccurredinonepatient(1hip,1.5%)oftheanteriorincision,andthewoundwashealedwiththeprolongedwounddressing.Atthelastfollow-up,painhaddecreasedinallpatients,andthemeanVASreducedfrom5.2pointspreoperativelyto1.37pointspostoperatively(p = 0.000)(Table2).  Table2.Pre-operativeandthelastfollow-upcomparisonVariablesPre-operativeThelastfollow-up       Z/T-valuep-valueTönnisgrade(%)                  − 0.816   0.414 Grade052(80.0)55(84.6)         Grade113(20.0)9(13.8)           Grade20(0)       1(1.5)            mHHS    72.19 ± 8.87   91.33 ± 4.42   − 23.630       0.000VAS5.23 ± 0.86     1.37 ± 0.94     39.502    0.000LCEangle(°) 4.26 ± 9.17     32.47 ± 3.09       − 26.102 0.000ACEangle(°)0.69 ± 8.32     31.31 ± 4.73       − 32.051 0.000AIangle(°)    26.28 ± 7.45   3.89 ± 3.04     26.601       0.000ThevaluesaregivenasthemeanandstandarddeviationmHHSmodifiedHarrisHipScore,LCElatercenter-edge,ACEanteriorcenter-edge,AIAcetabularindex  Forallpatients,themHHSsignificantlyimprovedfromameanpreoperativevalueof72.2pointsto91.3pointsatthelastfollow-up,andmHHSwasexcellentin40(61.5%)hips,goodin24(36.9%)hips,andfairinone(1.5%)hip.Thedegreeofaffectedhiposteoarthrosisdecreasedin4(6.2%)hips,remainunchangedin59(90.8%)hips,andincreasein2(3.1%)hips.AccordingtomHHSscoreandthechangeofTönnisgrade,40(61.5%)hipshadanexcellentresult,22(33.8%)hipshadagoodresult,3(4.6%)hipshadafairresult.Threepatients(3hips;4.6%)hadanunsatisfactoryresult,and55patients(62hips;95.4%)withasatisfactoryresult.Theaveragepostoperativelateralcenter-edge,anteriorcenter-edgeandanteriorcenter-edgewereimprovedsignificantlythanthatofpreoperative(p = 0.000)(Table2).Asymptoticgrade-1heterotopicossificationswerefoundin2patients(2hips;3.1%)whoreceivednoadvancedtreatment.Furthermore,agoodpreoperativefunctionalscoremaybeassociatedwithasatisfactoryoutcome(p = 0.075),andthepossibleriskfactorsthatwereanalyzedtodeterminewhethertheywererelatedtounsatisfactoryresultarelistinTable3.  Table3.PossibleriskfactorsrelatedtoanunsatisfactoryoutcomeVariablesSatisfactoryoutcome(N = 62) Unsatisfactoryoutcome(N = 3)   p-valueAge(year)      27.7 ± 8.07     37.0 ± 10.82   0.472BMI(kg/m2)  22.0 ± 2.98     23.4 ± 4.14     0.812DegreeofOA(Tönnisgrade)0.19 ± 0.40       0.33 ± 0.58     1.000Durationofsurgery(min)     106.8 ± 39.22       95.0 ± 5.00     0.898Intraoperativebloodloss(ml)492.1 ± 138.58       500.0 ± 100.00      1.000Durationoffollow-up(months)    35.5 ± 10.68       30.0 ± 9.17     0.741PreoperativemHHS(points) 72.8 ± 8.46       58.7 ± 6.94     0.075PreoperativeVAS(points)     5.2 ± 0.85       6.0 ± 1.00       0.964PreoperativeLCEangle(°)    3.9 ± 9.22       12.2 ± 1.78     0.065PreoperativeACEangle(°)   0.3 ± 8.17       9.7 ± 7.22       0.224PreoperativeAIangle(°)26.5 ± 7.54     22.4 ± 4.10       0.514ThevaluesaregivenasthemeanandstandarddeviationBMIbody-massindex,OAosteoarthrosis,mHHSmodifiedHarrisHipScore,VASvisualanalogscale,LCElatercenter-edge,ACEanteriorcenter-edge,AIAcetabularindex  DiscussionDevelopmentaldysplasiaofthehip(DDH)isacongenitaldevelopmentaldeformitythatismorecommoninwomen,andmostpatientshaveclinicalsymptomsbetween20and40yearsold[24].Inthisstudy,amongthe58patientswithameanageof28.1yearsattimeofsurgery,52(89.7%)caseswerewomen.Inordertopreventsubluxationordislocationofthehipattheearlystage,patientshouldreducejointloadandavoidhigh-intensityactivities,andevenconsiderpreventiveosteotomy.Intermofsurgery,thecurrentmainstreammethodismainlyreconstructiveacetabularosteotomybychangingthedirectionoftheacetabulum,includingBernesePAOandacetabularrotationosteotomy[4,11].Theseosteotomysurgeriescanrestoretheoptimalphysiologicalpositionoftheacetabulum,increasethecoverageoftheacetabulumonthefemoralhead,blockordelaythepathologicalprocessofosteoarthritis,andavoidordelaytheimplementationofarthroplasty.However,reconstructionoftheacetabularosteotomyhashightechnicalrequirements,largetraumaandvariouscomplications[4,11,13,14].Therefore,itisnecessarytoexplorenewsurgicalmethodtoreducesurgicaltraumaandsurgicalcomplications.Inthisstudy,wehavedescribedanew,safeandeffectivemodifiedS-PorBikiniapproachwithaposterolateralassistedsmallincisionfortheBernesePAO.Asisknowntoall,theopensurgicaltechniqueandPAOinternalfixationaretheacceptedtreatmentoptionsforacetabulardysplasia[4,11,12].Overthepastyear,severalsurgicalprocedureshavebeentriedforPAO.Khanetal.[14]havedescribedanew,safeandeffectiveminimallyinvasiveperiacetabularosteotomyusingamodifiedS-Papproach,andtheirresultsdemonstratedthatgoodcorrectioncanbeachieved,withsatisfactoryfunctionalresultsandalowcomplicationrate.Koetal.[5]havereportedamodificationofthesphericalacetabularosteotomywithuseofamodifiedOllierapproach,andfoundthisapproachismorereadilylearnedcomparedwithotherperiacetabularosteotomies.Isaksenetal.[1]reportedthatperiacetabularosteotomythroughtheanteriorintrapelvicapproachcanbeperformedsafelyandwithsatisfactoryresultsatmedium-termfollow-up.Inourcurrentstudy,allpatientsunderwentosteotomyusingthemodifiedS-Papproachwithaposterolateralassistedincisiontoroutinelyprotecttheintegrityofthelongheadandtheretroflexionheadoftherectusfemoris.Protectingtheintegrityoftherectusfemoristhroughaposterolateralassistedincisionreducesintraoperativebleeding,reducessurgicaltimeandhospitalstay,andreducessurgicalcomplications,includingsciaticnerveinjury.Ourresultsdemonstratedthatthismethodcanachievegoodcorrectioneffect,satisfactoryfunctionaleffectandlowcomplicationrate.Inaddition,thefunctionalimprovementandreorientationnormalizationwerenotsignificantlydifferentfromthosereportedintheliterature[8,14].TheBerneseosteotomywiththisnewapproachusuallyminimizessofttissueandnervedamage.Therefore,wehavereasontobelievethatthisdouble-incisionapproachisabetterchoiceforBernesePAO.Somereportshaveshownthatanadditional1to1.5hoftheoperationtimewasrequiredwhenperformingPAOwiththeuseofadouble-incisionapproach[8,25].Inthisstudy,theposterolateralassistedincisionprovidedarelativelyincreasesurgicalfiledofvisionandeffectivelymatchedtheproceduresassociatedwithPAO.Ontheonehand,surgicaldislocationofthehipcanbeattemptedthroughtheposterolateralassistedincisionwhennecessary.Thisposterolateralassistedincisioncanfullyexposetheacetabulumandfemoralhead,preservebloodsupplytothefemoralhead,provideanearly360°viewofthefemoralheadandacetabulum,contributetothediagnosisandtreatmentofjointcapsuledisease,andprotectthesciaticnerve.Ontheotherhand,ithelpscompleteischialosteotomyunderdirectvision,reducethedifficultyofischialosteotomy,andfullyprotectthesciaticnerveatthesametime.Therefore,ourresultsshowedthatnoneoftheosteotomylinespenetratedthehipjoint.Noneoftheposteriorcolumnsoftheacetabulumwerefracturedandnoneofthesciaticnervesweredamaged.Furthermore,theimagingindicatorsandtheaveragemHHSweresignificantlyimprovedatthelastfollow-up,andtheoperationtimedidnotincreasesignificantlycomparedwithtraditionalPAO[4,26],whichwouldbeattributedtocompletetheischiumosteotomyunderdirectvisionandreducethetimeofC-armfluoroscopy.Atthelastfollow-up,thepatients’hippainsymptomsimprovedsignificantlycomparedtothatbeforeosteotomy.Onlytwo(3.1%)patientshadanincreaseinthegradeofosteoarthrosis,andnopatientshadavascularnecrosisofthefemoralheadduringthefollow-upperiod,butthelong-termresultsrequirefurtherfollow-up.TheriskofbloodtransfusionrequiredfortheBernesePAOprocedureisverylow,andtheamountofbloodlossisrelatedtothepatient’spostoperativefunctionalexercise.Foracetabularosteotomy,theamountofbloodlossreportedwasdifferentinpreviousliteratures.Somescholarsreportedthattheaveragebloodlosswasashighas2000ml[27],andsomeotherreportsshownthatthemeanbloodlosswas800ml,1400ml,or2092mlusingthemodifiedS-Papproach,orI–IIapproach,orilioinguinalapproach,respectively[26].However,thesearticlesdidnotexplainwhetherthevolumeofbloodlosswasintraoperativebloodlossorperioperativebloodloss.Theallogenicbloodtransfusionrateis1.2%afteramodifiedS-Papproach[14].Inthecurrentstudy,theintraoperativeestimatedbloodlosswasdeterminedfromdataontheclinicalchartsasthebloodcollectedfromsuctioningandtheweightofthesaturatedsponges.Themeanintraoperativebloodlosswas402.8ml,and2patientsrequiredapost-operativeallogenicbloodtransfusion.Thereareseveralmainreasonsfortherelativereductioninbloodloss.Firstly,wecalculatedtheamountofbleedingduringsurgery,butdidnotincludepostoperativewounddrainageandhiddenhemorrhage.Secondly,theposterolateralassistedincisioncontributestocompleteischialosteotomyunderdirectvision,andthissurgicalmethodsavesthesurgeon’stimetotouchtheischiumfromthefrontandavoidsthedisadvantageofinconvenienthemostasisoftheanteriorapproach.Thirdly,theposterolateralassistedincisionshortensthelengthoftheconventionalincision,andnaturallyreducesthesofttissueinjuryoftheconventionalincision.Finally,wehadadoptedanintravenousinfusionofTXAforreducingbloodlossandtransfusionrates[28].However,surgeonsshoulddynamicallymonitortheserumbloodcoagulationprofilesduringtheperioperativeperiod,avoidingcomplicationsoccur.Inthisstudy,weobservedalessfrequency(1.5%)ofdelayedwoundhealinginpatientswiththedouble-incisionapproach,andnopatienthadpostoperativesuperficialaswellasdeepinfections.Thepatientwithdelayedwoundhealingwashealedwithprolongedwounddressing.Theresultcouldbeattributedtoasufficientlybridgeofintactskinbetweenthetwoincisions.Wehadleftanintactskinbridgeofatleast5cmwidthbetweenthetwoincisions.Anydelayinwoundhealingmayputthepatientatriskofdeepinfection.Althoughtheliteraturehadshownthattherateofinfectionafterpelvicosteotomieswasrelativelylow,anymethodsthatreducestheriskofwoundhealingproblemsshouldbeused[6,7,25].Furthermore,theanalysisofpossibleriskfactorshasidentifiedthatunsatisfactoryoutcomemaybenegativeinfluencedbythepoorpreoperativefunctionalscore.Inprinciple,theearliertheosteotomyoperation,thebettertheeffect.InjurytoLFCNisawell-knowncomplicationafterthePAOsurgery.However,theincidencesofLFCNinjurywerereporteddifferentlyfromdifferentsurgicalapproachesanddifferentresearchreports.TheincidencesofcompleteorincompleteLFCNinjuryhavebeenreportedfrom30to63%withdifferentsurgicalapproaches[1,6],andasystemreviewshowntherateofcompleteLFCNinjurywas6.14%[4].LFCNnerveinjuryhasbeenreportedtobearound30%afteramodifiedS-Papproach[14],about10.5%afteramodifiedOllierapproach[5],about14%afterananteriorintrapelvicapproach[21],andabout6.7%[24]aftertheoperativetechniquesinitiallydescribedbyGanzetal.[7].Whenthetensioninducedbytractionorcompressionisappliedtoanerve,boththeextrinsicandintrinsicvascularsupplieswouldaffecttheneuralischemia.Inthepresentstudy,therateofLFCNinjurywas9.2%andtherateofcompleteLFCNinjurywas3.1%.WebelievedtherelativelyreducedrateofLFCNinjurywasownedtotheposterolateralassistedincision,whichcanreducethetensionofperformingtheischialosteotomyfromtheanteriorapproach.However,thelimitedsamplewouldaffecttheincidence.Whateverapproachesadopted,keepingthenervewithinthefascialsleeveofthetensorfascialatacanhelptoprotectthenerve.Inaddition,thereisalearningcurvefortheBernesePAOwhichrequiresconsiderableexperiencebeforemasterthispelvissurgery.KhanOHetal.[14]acknowledgedthattherewillundoubtedlybealearningcurvewiththeuseofminimallyinvasivetechniquethroughamodifiedS-Papproachandtheyhaveconsistentlyusedtheapproachinmorethan250furtherpatients.Fortheanteriorintrapelvicapproach,IsaksenKFetal.[1]believedthatalearningcurvefortheoperativesurgeonsshouldalsobetakenintoconsideration.Therefore,alearningcurvefortheoperatingsurgeonsmustbeconsidered[1,8].Wehadusedtheposterolateralassistedincisionforcompletingischialosteotomyunderdirectviewwithoutthehelpofimageintensifier,whichnaturallyreducesthecomplexityofPAOsurgery,especiallyforbeginner.Thereisnosignificantdifferenceinclinicalandradiographicassessment(includingmHHS,VAS,andreliableacetabularreorientation)inthecurrentstudies[4,6,8,14].OurresultshaveshownthattheposterolateralassistedincisionwithmodifiedS-Papproachwassafeandallowsoptimalre-orientationoftheacetabulum.Overall,periacetabularosteotomyusingmodifiedSmith-PetersenorBikiniapproachwithposterolateralassistedsmallincisioncannotonlygetsatisfactoryresults,butalsoshortenthelearningcurve,especiallyforbeginner.Weacknowledgeseverallimitationstothisstudy.First,thestudywasaretrospectivedesign,norandomization,andarelativelysmallsamplesizeofpatients.Withthelearningcurveandrelativelylowincidence,itwashardtoobtainalargernumberofpatients.Butfurtherstudywithlargersampleisrequiredinourfutureresearch.Second,whilethereisundoubtedlyalearningcurveforPAOusingthisdouble-incisionapproach,thelearningtimeissignificantlyshorterthanothertraditionalapproaches.Finally,wecannotpredictthelong-termfailureratebecausetherelativelyshorttomid-termfollow-upperiodalsocouldaffecttheclinicalandradiographicresultassessment.Furtherresearcheswithlargersampleandlongerfollow-uparerequiredtoassesstheresultsoftheuseofthisdouble-incisionapproachforBernesePAO. ConclusionThemodifiedS-PorBikiniapproachwithaposterolateralassistedsmallincision,byprovidingadirectviewforischialosteotomyandreducedsofttissueandnervesinjury,allowssafeaccurateosteotomiesinareasonableoperativetime,withreducedbloodlossandtransfusionrequirement,lowcomplications,satisfiedfunctionaloutcomeandgoodradiologicalcorrection.Moreimportantly,thisnewdouble-incisionapproachofPAOhasanadvantageofreducedlearningcurve,especiallyforbeginner.改良S-P或Bikini入路后外侧辅助小切口，提供坐骨截骨的直接视野，减少软组织和神经损伤，在合理的手术时间内实现安全准确的截骨，减少失血和输血需求，并发症低，功能结果满意，影像学矫正良好。更重要的是，这种新的双切口入路具有缩短学习曲线的优点，尤其适合初学者。

全膝关节置换假体周围关节感染的Floating膝关节Arthrodesis48例报告（2024）FloatingKneeArthrodesisAfterProstheticKneeInfection:AReportof48Cases Ortega-YagoA,Pedraza-CorbiA,Arguelles-LinaresF,Baeza-OlieteJ.FloatingKneeArthrodesisAfterProstheticKneeInfection:AReportof48Cases[J].JArthroplasty,2024,39(2):494-500. 转载文章的原链接1：https://pubmed.ncbi.nlm.nih.gov/37572716/ 转载文章的原链接2：https://www.arthroplastyjournal.org/article/S0883-5403(23)00807-0/abstract AbstractBackgroundKneearthrodesisisameansofavoidingabove-kneeamputationafteraprostheticjointinfection(PJI).Theobjectiveofthisstudywastoanalyzetheresultsoffloatingkneearthrodesisinpatientswhohadahistoryofaprosthetickneeinfection.Theanalysisconsistedofdeterminingreinfectionrates,functionalresults,andthesurvivalofarthrodesis. MethodsTherewere48patientswhounderwentacementedfloatingkneearthrodesisincasesofPJIretrospectivelyincludedinthestudy,havingbeenoperatedonbetween2012and2020.Inadditiontobeingevaluatedclinically,analytically,andradiographically,thepatientswereassessedfunctionallybymeansofanewly-createdscale. ResultsAtameanfollow-upof4years(1yearto9years),7patientssufferedreinfection(14.6%).Therecurrenceofinfectionwasnotobservedtobesignificantlyaffectedbysex(P=.16),age(P=.09),orthetypeofsurgerypreviouslyundergone(P=.18),norwastheMcPhersonHostGrade(P=.4)observedtohaveasignificanteffect.PatientswhohadaMcPhersonLimbGrade3weremorelikelytosufferreinfectionthanthosewithaMcPhersonLimbGrade2(P=.034).Therewere26patients(54%)fullyevaluatedandscoredontheKneeArthrodesisFunctionalScale(BAOR).For11patients(42%),theresultswereevaluatedasexcellent,for11(42%)acceptable,for3(12%)low,andfor1(4%)poor. ConclusionThearthrodesisnailisaneffectiveandsafeprocedureforpatientswhohavearecurrentPJI,providinganeffectivealternativewhenthecriteriaforanewrevisiontotalkneearthroplastyarenotmet.对于复发性PJI患者，关节融合术是一种有效且安全的手术，当不符合新翻修全膝关节置换术的标准时，它是一种有效的替代方法。 Arevisiontotalkneearthroplasty(r-TKA)forPJIs(prostheticjointinfection)isachallengeforsurgeonsduetothemorbidityandmortality,poorsoft-tissuecoverage,andlossofbonestockassociatedwiththepatientswhoundergothisoperation[1-4].Forthisreason,kneearthrodesis(KA)afteraPJIisawidelyacceptedrescuemethodsinceitobviatesabove-kneeamputation[5,6].Currently,performingaKAisrestrictedtoasmallnumberofcases.ThemostacceptedindicationsareaninfectionofTKAwithahighriskofrecurrence,anunreconstructibleextensormechanism,astiffpainfulkneeafterprimaryorr-TKA,largebonedefects,andbadlydamagedsofttissuewithpoorcoverage[7,8].AKAcanbeperformedwithexternalfixation,directplatingfixation,orintramedullarynailing,orbystabilizationwithoutbonefusion(floatingarthrodesis).Currently,the2mostwidelyusedmethodsareexternalfixationandtheintramedullarynail.Externalfixationallowsoptimaltibio-femoralcompressionandcorrectlimbalignment;however,ithasahighercomplicationratethanintramedullarynailingdoesandtakeslongertoproducebonefusion[9,10].Bothsystemshavethedisadvantagesoftendingtocauseexcessivelimbshorteningandofbeingassociatedwithadifficultyinachievingbonefusioninapreviouslysepticenvironmentwithextensiveboneloss[11].AfloatingKAstabilizesthekneewithoutbonefusion,doingsobymeansoffixationwithanintramedullarynailandtheinterpositionofacementblock.Itallowsearlyweight-bearing,aswellasthepossibilityofadaptingthelengthofthelimbtoreduceresidualdiscrepancy[3,11].TheobjectiveofthisstudywastoanalyzetheoutcomesoffloatingKAinpatientswhohadahistoryofPJI.Theanalysisisbasedonadeterminationofreinfectionrates,clinicalandfunctionalresults,aswellasthesurvivalofarthrodesis. MaterialandMethodsAretrospectivereviewwasconductedof48patientsoperatedonatourhospital(ReferralCenterforComplexBoneandJointInfections)betweenJanuary1st,2012andDecember31st,2020.All48underwentKA,withoutbonefusionandwiththeimplantationofacementedintramedullarymodularnail(floatingarthrodesis),havingpreviouslyundergoneprostheticsurgerywhichhadfailedduetoinfection.Therewere30patients(62.5%)whowerewomen,and18(37.5%)men.Themeanagewas72years(47to91).Duringthisperiod,231r-TKAswereperformedin1-or2-stageexchanges.Ofthese,15.0%wereKAs.TheindicationsforaKAwere:14casesofanunreconstructibleextensormechanism,5casesofanunreconstructibleextensormechanismplusseveresoft-tissuedefect,16casesoflargebonedefects,3casesoflargebonedefectswithseveresoft-tissuedefect,and10casesofpatientsbeingreferredfromanothercenterwhereaKAhadbeenperformedwithasubsequentinfection.TheinclusioncriteriawerethatthepatientshadahistoryofchronicTKAorarthrodesisnailinfectiondiagnosedaccordingtothediagnosticcriteriaoftheInternationalConsensusMeetingofPhiladelphia2013[12]andthattheyreceivedfollow-upcareforatleast1year.TheexclusioncriteriawereKAduetoatumororfractureandthatthepatientsdidnotmeettheinclusioncriteria.Forthediagnosisofreinfection,thePhiladelphiacriteriawerealsoused. PatientsThemeanbodymassindexofpatientswas29.70(23to37)(Table1).  Table1SummaryofPatientDemographicsandPriorSurgicalData.Meanage72(47to91)Sex 30women(62.5%)18men(37.5%)Meanbodymassindex(BMI)      29.70(23to37)AmericanSocietyofAnesthesiologists(ASA)PhysicalStatusClassificationSystem   I→1patient(22.2%)II→25patients(55.56%)III→17patients(37.78%)IV→2patients(4.44%)Meanpreviousinterventions 4McPhersonHostGrade TypeA:15patients(31%)TypeB:26patients(55%)TypeC:7patients(14%)McPhersonlimbgrade  Type1:0patientsType2:36patients(75%)Type3:8patients(17%)Unknown:4patients(8%)Typeofreplacement      One-stage:4patients(9%)Two-stage:44patients(91%)Extensormechanismdeficit   21patients(43.7%)  For36patients(75%)surgerywasrequiredasaresultofTKAinfection;5ofthese(10.41%)hadahistoryofprimaryTKAandtheother31(64.5%)hadundergoner-TKA.Therewere10patients(20.8%)whohadaprevioushistoryofarthrodesisnailinfection,and2patients(4.2%)sufferedfromkneestiffnessafterinfectedTKA.Themeannumberofprevioussurgicalinterventionsonthepatientswas4.Theunderlyingpathologyofthepatientswasasfollows:3(6.25%)hadaprevioushistoryofneoplasia,4(8.3%)hadadvancedchronicrenalfailure,4(8.3%)hadautoimmunediseases,3(6.25%)hadmoderate-severeliverdisease,11(23%)haddiabetesmellitus,1(2%)hadundergonearenal-pancreatictransplant,and4(8.3%)hadmoderate-severelungdisease.TheAmericanSocietyofAnesthesiologists(ASA)PhysicalStatusClassificationSystemwere:ASAIfor1patient(2.22%);ASAIIfor25patients(55.56%);ASAIIIfor17patients(37.78%);andASAIVfor2patients(4.44%).Priortosurgery,theoptimalantibiotictreatmentwasdetermined,andthepatientswereclassifiedaccordingtotheMcPhersonsystem[13],whichconsidersthetypeofinfection,thetypeofhost(Auncompromised,BcompromisedandCseverelycompromised)andthelocalconditionsofthelimb(1uncompromised,2compromised,and3severelycompromised).AsregardstheMcPhersonHostgrade,thiswastypeAin15patients(31%),typeBin26patients(55%),andtypeCin7patients(14%).AndasfortheMcPhersonlimbgrade,therewerenotype1patients,36type2patients(75%),8type3patients(17%),and4patients(8%)whosetypecouldnotbedetermined(Table1). SurgicalDataOne-stagearthrodesiswasperformedon4patients(9%)and2-stageexchangeontheremaining44(91%).Ineverycase,thearthrodesisnailwascemented.In21patients(43.7%)adisruptionoftheextensormechanismwasobserved.Regardingthemicroorganismsisolatedfromthepatients,therewere2negativecultures(4.15%),7isolatesofmethicillin-susceptibleStaphylococcusaureus(14.5%),1ofmethicillin-resistantStaphylococcusaureus(2%),8ofStaphylococcusepidermidis(16.6%),21ofpolymicrobialinfection(43.1%),1ofPseudomonasaeruginosa(2%),2ofStaphylococcuslugdunensis(4.15%),and6ofothermicroorganisms(13.5%)(Figure1).  Fig.1Distributionofthetypeofmicroorganismisolated.MRSA,methicillin-resistantStaphylococcusaureus;MSSA,methicillin-susceptibleStaphylococcusaureus.  SurgicalTechniqueTheWaldemarLinkEndo-ModelCementedKneeFusionNail(LINKEndo-ModelSL,Hamburg,Germany)wasimplantedinallthepatients(Figure2).Surgerywasperformedin1-or2-stageexchanges.Inthe2-stageexchangethekneeprosthesiswasremovedandsenttothemicrobiologylaboratoryforsonication.Tissuesamples(5to8samples)weretakenforcultureinallcases;exhaustivedebridementanddilutedpovidone-iodineirrigationwereperformed.Anantibiotic-loadedarticulatingspacer(Vancogenx-SpaceKneepreloadedwithGentamicinandVancomycin,Italy)wasused.Incasesofmassiveboneloss,astaticspacerusingCOPALG+V(Heraeus,Hanau,Germany),plus2gramsofvancomycinforeach40-grampacket,wasemployed.Thesecondstagewasgenerallyperformedbetween6weeksto3monthslater,whentheerythrocytesedimentationrateandC-reactiveproteinlevelshaddecreased,andthesurgicalwoundwashealed.Thespacerwasremovedandsentforsonication,tissuesamples(5to8samples)weretaken,anewdebridementandirrigationwasperformed,andthearthrodesisnailwasimplanted.Theintramedullarycanalswerereamedpriortonailinsertionsoastodeterminethenaildiameter.Thefemoralandtibialnailstemswerecementedindependentlyandjoinedtogetherafterdeterminingthedesiredlengthofthelowerlimb.Thepatientswerenotimmobilizedaftersurgeryandweight-bearingontheaffectedlimbbeganatanearlystage.Therewere23patients(48%)whorequiredplasticsurgery,oneoftheseundergoingalatissimusdorsiflap,2requiringskingrafting,and20undergoinganisolatedmedialgastrocnemiusflap.  Fig.2StandardAP(antero-posterior)andlateralx-rayviewsofanintramedullarymodularnail.  TheantibioticwasprescribedbytheInfectiousDiseasesUnit,usinganempiricalregimenwhichdidnotincludemicroorganismspreviouslyisolated.Iftheantibioticswerechanged,thiswasdoneinaccordancewiththeantibiogramofthemicrobiologicalsamplestakenduringsurgery.Theantibiotictherapyconsistedofaninitial2weeksofintravenousadministration,followedbyoralantibiotictherapyuntilaminimumof6weeksoftreatmentwascompleted.Thefinaldurationsofthetreatmentsvariedaccordingtothemicroorganism. EvaluationPatientswereclinicallyandradiologicallyevaluatedbymeansofseverallaboratoryparameters.Theminimumfollow-upwas2years,duringwhichtimethestatusofthesurgicalwoundandthelaboratoryparameters(erythrocytesedimentationrate,creactiveprotein)wereascertained,anditwasdeterminedwhetherasinushadappearedornot.Tocheckforsignsofosteolysisorloosening,x-raysweretakenat3months,6months,12months,anduptoaminimumof2years.Limb-lengthdiscrepancywasassessedbyphysicalexaminationandradiographicmeasurement.Anewscalewascreatedtoevaluatethefunctionalresultsofthearthrodesisafteraminimumof5yearsaftersurgery(KneeArthrodesisFunctionalScale,theBaeza-Ortega(BAOR)scaleandpatientsweregivenscoresonit.TheBAORscaleconsistsof4itemsthatevaluatedifferentparametersofKA,includingthepainsufferedbythepatient,theabilitytoperformbasicactivitiesofdailyliving,andtheuseofsupportdevices.Themaximumscoreis30pointsandtheminimumis0points.Aresultof23to30pointsisconsideredpoor,15to22low,7to14pointsacceptable,and0to6excellent(Table2).  Table2Baeza-OrtegaScale(KneeArthrodesisFunctionalScale)andLevelofSatisfactionWithKneeArthrodesis.PainatRest   •Never(0Points)•Sometimes(1Point)•Often(2Points)•Always(3Points)Pain•Isitpainfultowalk?(from0to3):•Isitpainfulwhengoingupordownstairs?(from0to3)•Doesthepainwakeyouatnight?(from0to3)•Isitpainfultostand?(from0to3)DifficultieswithBADL  Assumingthattheinabilitytoflexthekneecreatesseriousdifficultiesindailylife.Howdifficultisitto…?•Walk(from0to3)•Sit(from0to3)•Getinandoutofthecar(from0to3)•Getoutofbed(from0to3)Useofsupportproducts•None(0points)•Walkingstick/crutch(1point)•2walkingcrutches/walker(2points)•Wheelchair(3points)Levelofsatisfactionwitharthrodesis    Areyousatisfiedwiththearthrodesis?•Notsatisfied•Notverysatisfied•Satisfied•VerysatisfiedTheMaximumScoreis30Points,23to30PointsisConsideredaPoorResult,15to22PointsaLowOne,7to14PointsanAcceptableOne,and0to6PointsanExcellentOne.BADL,basicactivitiesofdailyliving.  Theglobalsatisfactionlevelofthepatientwiththearthrodesis(dissatisfied,notverysatisfied,satisfied,orverysatisfied)wasnotincludedinthescoreonthescale(Table2).TheinfectionwasconsideredresolvedwhentherewasnoclinicaloranalyticalevidenceofinfectionaccordingtothecriteriaoftheInternationalConsensusMeetingofPhiladelphia2013[12].Whererecurrencesofinfectionoccurred,theintervalsuntiltheirappearance,thenumberofpatientsrequiringsurgicalreintervention,andthetypesofsurgeryperformedwerenoted.[12]InternationalConsensusonperiprostheticjointinfection.http://www.msis-na.org/international-consensus/.[Accessed16December2013].Thetreatmentwasconsideredtohavefailedwhenafistulaappeared,therewasaneedforamputationorsuppressivetreatment,orthepatientsneededfurthersurgeryontheaffectedlimbduetoothersepticorasepticcauses. DataAnalysesThestatisticalanalyseswerecarriedoutusingR-commanderv3.4.3(McMasterUniversity,Ontario,Canada)forMac.WeappliedLillieforstestfornormality[14],fromwhichwedeterminedthatwehadtousenonparametrictests.Ourpoweranalysiswasastandardone(80%,1-β=80).TheKaplan-Meiersurvivalcurvewasgeneratedtoanalyzetheinfectionrelapserate,anddifferencesintheprobabilityofinfectionrecurrencewereanalyzedusingCoxregressions.ToevaluatetheBAORscale,weappliedtheCronbachalfatestforassessingreliability,obtainingaresultof0.87.WealsoappliedtheSpearmancorrelationtesttomeasurethevalidityofeachitem,witharesultof>0.5ineverycase.Also,weappliedtheChi-squaredtest.ThesignificancelevelwassetatP<.05. ResultsFollow-UpandComplicationsThemeanfollow-uponthepatientswas4years(1yearto9years).Duringthefollow-up,15patients(31%)experiencedsometypeofcomplication.Themeantimeforsurgicalrevisionofthearthrodesiswas36±5monthsafterthemainoperation.Therewere7patientswhosufferedareinfection(14.6%,Figure3),with5ofthemrequiringafurtheroperation(10.4%)and2requiringsuppressivetreatment(4.2%)duetotheirpreviouspathology.Themeantimeforreinfectionwas33.6±11months(2.8years).Ofthe5patientswhounderwentafurtheroperation,1requiredsuppressivetreatmentafterisolateddebridementandirrigation,1requiredtheimplantationofacircularexternalfixatorpriortoanewarthrodesis,1underwenta2-stageexchange,and2underwentanisolateddebridementbecauseofthehighassociatedmorbidity(Table3).In6patients(12.5%),thesamemicroorganismashadpreviouslybeenpresentwasisolatedonceagain,andinonepatient(2%),adifferentmicroorganism(Aspergillusterreus)wasisolated.  Fig.3Reinfectionsurvivalcurveduringfollow-up.Thelineisthesurvivalcurveandthedottedlinesaretheconfidenceintervals.  Table3PatientFollow-UpandComplicationsData.Follow-up      48±24moComplicationsReinfection:7patients(14.6%)-5interventions-2suppressivetreatmentProblemswithflap/graft:3patients(6.25%)Periprostheticfracture:1patient(2%)Asepticloosening:3patients(6.25%)Centralpartbreakage:1patient(2%)Reinfectiontime     33.6±10mo(2.8y)Leg-lengthdiscrepancy  1.6±0.5cmDeath     12patients(25%)  Oftheremainingpatientswhosufferedcomplications,3(6.25%)hadproblemswiththeflap/graft,1(2%)hadaperiprostheticfracture,1(2%)hadabreakageofthecentralcomponentofthearthrodesisnail,and3(6.25%)hadasepticloosening.Ofthewhosufferedanasepticloosening,2(4%)requiredcomponentreplacementandonerefusedtohaveanotherarthrodesisnailimplantedandconsequentlyunderwentanabove-kneeamputation.Themeanleg-lengthdiscrepancywas1.6centimeters(0.9to3)asmeasuredwithx-rays.Therewere12patients(25%)whodiedduringthefollow-up.However,osteoarticularinfectionwasnotthemaincauseofdeathinanyofthesecases.Themeantimebetweenthesecondinterventionanddeathwas5±1.5years(Figure4,Kaplan-Meiergraph).  Fig.4Kaplan-Meiergraphofmortality.  Therecurrenceofinfectionwasnotobservedtobesignificantlyaffectedbysex(P=.16),age(P=.09),orthetypeofsurgerypreviouslyundergone(primaryTKAP=.2,r-TKAP=.32,arthrodesisnailP=.18),norwastheMcPhersonHostGrade(Figure5,P=.4)observedtohaveasignificanteffectinthisrespect.PatientswhohadaMcPhersonLimbGrade3werefoundtobemorelikelytosufferreinfectionthanthosewhohadaMcPhersonLimbGrade2(Figure6,P=.034).  Fig.5ReinfectionsurvivalcurvedependingontheMcPhersonHostGrade.Nosignificantdifferenceswerefoundintheprobabilityofsufferingarelapse(P=.4).  Fig.6ReinfectionsurvivalcurvedependingontheMcPhersonLimbGrade.PatientswithaMcPhersonLimbGrade3weremorelikelytosufferarelapse(P=.034).  FunctionalDataOfthe48patientsincludedinthestudy,26(54%)werefullyevaluatedand,consequently,scoredontheBAORscale.Ofthese26,11(42%)obtainedanexcellentresult,11anacceptableone(42%),3alowone(12%),and1(4%)apoorone(Figure7).Regardingoverallsatisfaction,17patients(64%)wereverysatisfiedwiththearthrodesis,6(24%)weresatisfied,2(8%)werenotverysatisfied,and1(4%)wasnotsatisfied(Figure8).Therewasacorrelationbetween“satisfaction”andthe“functionalresults”ofpatients(P=.0009).  Fig.7GlobalresultsoftheBaeza-Ortegascale.BAOR,Baeza-Ortega.  Fig.8Overallsatisfactionofpatientswitharthrodesis.  DiscussionThemanagementofrevisionsurgeryforthetreatmentofPJIischallengingnotonlyintermsofinfectioneradicationbutalsobecauseofthebonelossandsecondarysofttissuetowhichpatientswhoundergothisoperationareliable.Comparingfavorablywithantibioticsuppression,repeated2-stageexchangearthroplastyandamputation[10,15,16],arthrodesishasbeenshowntobeaneffectivemethodfortreatingPJI,obtainingacceptablefunctionaloutcomeswhenr-TKAhasfailedduetoreinfection.Arthrodesisnailshavecertainadvantagesoverotherarthrodesisdevices.Forexample,incomparisonwithexternalfixators,theyaremorelikelytoresultinrotationalandaxialstabilityandtocorrectthediscrepancythatoftenoccursaftermultipleoperations.Allourpatientsunderwentsurgerywithacementedintramedullarynailandwithoutbonefusion.Thisprocedurefacilitatescontrolovertheshorteningoftheaffectedlowerlimb.Moreover,itsignifiesareductionintheproblemofunionfailure,which,withtheexternalfixator,cantakeplaceinupto10%ofcases[17-20].Thefusionratesofarthrodesisareoftenlowerwhenexternalfixationisusedthanwhenanarthrodesisnailisimplanted,sinceintheformercasethediscrepancyisusuallygreaterandthereisalsoariskofinfectionfromthepins[9,21,22].Leg-lengthdiscrepancyisanimportantparameter,sincewhenitisexcessive,thepatientfindswalkingphysicallydemanding.Itisrecommendedthatthediscrepancybelessthan2centimeters[23,24].Theresidualdiscrepancyinourcohortwasameanof1.6centimeters,aresultsimilartothosefoundinotherstudies[25]andlowerthanthosegiveninstudieswhereintramedullarynailarthrodesiswasperformedforbonefusion[26].Therewere15patients(31%)whoexperiencedsomecomplicationsduringthefollow-up.Themeansurgicalrevisionratewas36months.Thesedataaresimilartothosefoundinstudieswherethesurvivalrangesfrom16to72months[15,27,28].Despitetheuseofsystemicantibioticsandaggressivedebridement,weobservedareinfectionrateof14.6%ofpatientswiththemeanreinfectiontimebeingapproximately34months.Thesedataaresimilartothosefoundinotherstudies[26]andlowerthanthosegivenforothercohorts,wherethereinfectionratesrangefrom19.4to26%[15,16,25].Wedidnotfindadirectrelationshipbetweentheprobabilityofsufferingreinfectionandthepatient'sMcPhersonHostGrade(P=.4).Therecurrenceofinfectionwasnotobservedtobesignificantlyaffectedbysex,age,orthetypeofsurgerypreviouslyundergone.WeobservedthatpatientswithaMcPhersonLimbGradetype2werelessliabletoreinfectionthanthosewithatype3(P=.034).Intheirstudy,Friedrichetalfoundthatapoorsoft-tissueconditionandahighMcPhersonLimbGradesignificantlyincreasedtheprobabilityofsufferingarelapseintoinfection[26].Thisdemonstratestheimportanceofanadequatecoverageofsoft-tissuedefectswheneradicatingtheinfection.Therewere25%ofourpatientswhodiedduringthefollow-up,althoughinnoneofthesecaseswasthemaincauseofdeathosteoarticularinfection.Themortalityrateinotherstudiesvariesbetween4and22%.However,itshouldbenotedthatthemeanageofourpatientswas72years,whichishigherthaninothercohorts[15,29].Sometimes,whenanarthrodesisfails,amputationistheonlysolution.Inourcohort,onepatientwhosufferedasepticlooseningrefusedanewarthrodesisand,consequently,requiredanabove-kneeamputation,whileanotherrefusedamputation.Ithasbeenseenthatforpatientssufferingrecurrentinfection,thefunctionalresultsofarthrodesisarebetterthanthoseofamputation[28-30].ForthefinalevaluationofthefunctionalresultsofKA,thepatientswerescoredontheBAORscale.Thescoringtookplace5yearsafterthemainoperation.Therewere26patients(54%)whowereabletosupplythenecessarydata.TheBAORscalewascreatedatourhospitalasaspecificmeansofevaluatingtheresultsofKA.MostofthestudiesthatexistintheliteratureusetheShortForm12and36HealthSurvey,WesternOntarioandMcMasterUniversitiesArthritisIndexortheOxfordKneeScore[3,15,16].ThesescalesarenotappropriatefortheassessmentofKA,sincetheyelicitlow-valueresponseswheneverthereisalackofkneeflexion[18,26](eg,theyfactorinpatients’responsesrelatedtodifficultywithbendingdowntothegroundandgettingup,orputtingonsocks).Forthisreason,wecreatedanassessmentscaleeliminatingthequestionsrelatedtoalackofflexion.Thescaleissimpleandreproducible,withitemsthatevaluatethepainsufferedbythepatient,theabilitytoperformbasicactivitiesofdailyliving,andtheuseofsupportdevices.Attheend,patientswereaskedtoratetheiroverallsatisfactionwithKA.Theratingtheygivehasnorepercussiononthescoreobtainedontheassessmentscale,sincetherearepatientswhowereverysatisfiedwiththeresultsoftheoperationdespitetheirachievinglowfunctionalresultsonthescale.Inourcohort,weobservedthat11patients(42%)achievedanexcellentoutcomeand11patients(42%)anacceptableone.Thisshowsthat,despitetheirfunctionallimitations,arthrodesisnailscanprovidepatientswithacceptableresultsintermsbothofthebasicactivitiesofdailylivingandofminimizingpain.Moreover,overallsatisfactionwasgivenas“verysatisfied”by17ofthepatients(64%)and“satisfied”by6ofthem(24%),whichdemonstratesthatthefunctionalresultsofthetreatment—involvinganinevitablelossofkneemotion—andtheoverallsatisfactionofthepatientdonotalwayscoincide.Gramlichetal[31]alsofoundthat88%ofpatientsintheircohortweresatisfiedwiththeoverallresultofthearthrodesis.Evidentlypatients’initialexpectationsstronglyinfluencehowsatisfiedtheyarewiththetreatmenttheyreceive,animportantfactorinthisrespectbeingthattheobjectiveofKAisinmanycasestorescuethelimbbyavoidingamputation.Regardingpain,theresultsofourstudyaresimilartothosefoundinothers[27,28];inthattheyindicatethatKAcanconsiderablyreducethepainsufferedbythepatient.Wecannotdenythatourstudyhassomepotentiallimitations.Althoughourpatientshavefollowedasimilarprotocolintheirtreatmentandfollow-up,localandgeneralcomorbiditiesareveryheterogeneous,whichcomplicatesthestandardizationoftheresults.Becauseourhospitalisareferralcenterforcomplexboneandjointinfections,allthepatientsinthisstudywereoperatedonatotherhospitalsbeforebeingtransferredherefordefinitivesurgery,whichfurtheraddstotheheterogeneityofourcohort.Thisstudyisretrospective,withasmallcohortofpatients,sothereisariskofmakingatype2statisticalerror;however,ourseriesislargerthanmostofthosecurrentlycitedintheliterature. ConclusionsThearthrodesisnailwithoutbone-bonefusionisaneffectiveandsafeprocedureforpatientswhohavearecurrentPJIbecauseitallowsearlyweight-bearing,correctsthelengthdiscrepancyofthelowerlimb,andallowsthekneetoremainstable.NorelationshipwasobservedbetweentheprobabilityofsufferingarecurrenceoftheinfectionandtheMcPhersonHostGrade.Patientswhohaveaseverelycompromisedlocalconditionofthelimb(McPhersonLimbGrade3)areathigherriskofreinfection.