髋关节盂唇损伤

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.

日常中髋关节疼痛的常见原因？我们如何有效预防髋关节疼痛？原创 刘立云髋关节镜人工髋关节团队发表于河南郑州导读： 日常中，髋关节疼痛是一种非常常见的疾病，从刚毕业的学生到年长的老人，似乎每个人都有患髋关节疼痛的风险，我们一般很难确切阐明为何自己会感到疼痛，但是正确的诊断疾病原因对于有效的治疗非常重要。髋关节疼痛通常位于前方、侧面或后方。髋关节前部疼痛包括由腹内或骨盆内原因引起的转移疼痛、髋屈肌损伤、以及由年轻人的盂唇撕裂或股骨髋臼撞击或老年人的骨关节炎引起的。髋外侧疼痛最常见于大转子疼痛综合征，包括臀中肌腱病变或撕裂、滑囊炎和髂胫束摩擦。髋关节后疼痛包括腰椎病变、伴有坐骨神经卡压的臀深综合征、坐骨-股骨撞击和腘绳肌腱病等相关疼痛。除了病史和体格检查外，可能还需要射线照相、超声检查或磁共振成像。1、髋关节周围核心肌肉拉伤（又称运动性疝气或运动性耻骨痛）如果你感觉腹股沟区域疼痛，可能是核心肌肉损伤所致，比如髋关节周围的肌肉或其它软组织拉伤/撕裂，如髋关节外展肌群、内收肌群等；这种损伤在“周末战士”运动群体中最为常见，日常中运动锻炼量不够，周么运动强度高，容易损伤髋关节周围肌肉，尤其是那些从事大量极端髋部扭动和转身运动的人群，这样髋关节周围肌肉损伤更常见。治疗方法：来医院进行正规的影像学或彩超检查，明确诊断，让受伤的肌肉休息几周而恢复，同时也可能会需要医生进微创手术来修复撕裂的髋关节周围肌肉。2、髋关节周围滑液囊炎如果你的臀部、大腿或臀部外侧疼痛，可能归咎于滑囊炎。各种原因导致的髋关节周围滑囊炎可能会出现髋关节周围持续性疼痛，出现在髂骨、耻骨、大转子或小转子等肌肉附着部位。我们更熟悉及更常见的为大转子滑囊炎及大转子周围疼痛综合征，这些多由于髋关节重复活动或急性创伤导致。有研究表明，虽然长时间行走或爬楼梯会使疼痛症状加重，但滑囊炎通常与活动相关的疼痛无关，其每天都会让患者疼痛，即使是睡觉是也不例外，随着机体年龄增长，滑囊炎会变得更加常见，尤其是对于60岁以上的人群。髋关节周围滑囊炎通常可以通过仔细的病史、患者的临床症状和体格检查来诊断，如果在初次诊断困难的情况下，我们可以结合肌肉骨骼超声检查来进一步诊断，肌骨超声在确认诊断方面可能非常有用，同时我们也可以依靠超声引导下实现局部注射治疗，目前我们单位（河南省洛阳正骨医院），已成熟开展此类技术。治疗方法：我们尝试在家中休息患侧髋关节，同时局部给予冰敷治疗，也可口服非甾体消炎止痛药物，有时候医生也会给你注射可的松来减缓炎症进展。一般建议保守治疗3个月，效果不明显，可考虑局部微创髋关节镜手术治疗。3、髋关节周围肌腱炎如果你很活跃，而你的髋关节屈肌（将膝盖和腿部向身体靠拢的一组肌肉）或腹股沟在你触摸或移动时很柔软，这种情况下你或许患上了肌腱炎。Nho解释道，拉伤或过度使用肌腱（将肌肉连接到骨头上的绳索）会造成反复的轻微损伤，最终导致髋关节的肌肉失衡；反复进行非常特殊活性的人群（比如足球运动员）可能机会面临严重疼痛所带来的风险。4、髋关节骨关节炎当髋关节中的软骨随着时间的推移逐渐磨损时，就会发生髋关节骨关节炎。由于年龄增长或者先前有髋关节损伤（股髋撞击症、盂唇撕裂），关节软骨异常磨损，股骨头和髋臼之间的关节间隙会逐渐变窄，最后软骨磨没了，就会出现骨对骨的摩擦。疼痛可能是钝痛、酸痛或剧痛，和活动有关，活动多了就疼痛，休息休息症状就会改善。最后骨对骨的摩擦会导致关节变形，僵硬，活动受限。5、股骨头坏死最常见的叫股骨头无菌性坏死，很多人都心有余悸。过量使用激素或饮酒会引起髋关节血供被破坏，骨细胞死亡，髋关节的骨形态逐渐崩坏。通常表现为日益加重的行走后髋关节前方和腹股沟区域疼痛，此外还有大腿、臀部和/或膝盖疼痛。         6、髋关节撞击FAI股骨髋臼撞击（FAI）是一种出现在年轻和中年人中的常见髋关节疾病。其特征是髋关节周围疼痛，主要感觉在腹股沟及外侧。简单的髋关节平片通常很难提供完整和有价值影像学证据，不利于临床诊断，同时需要医师具有相应髋关节疾病诊断基础。Ganz等人最早描述了“钳形”撞击（髋臼前部过度覆盖的结果）和“凸轮”撞击（非球形头部紧靠髋臼前部，通常髋关节屈曲）。众所周知，非球形股骨头是由于股骨头颈近端结构偏移异常引起的。这通常被描述为股骨颈的“枪柄样畸形”。髋关节撞击会在髋关节运动的极限处对髋臼盂唇造成重复性、反复性创伤，导致盂唇和软骨损伤，并可能在髋关节骨性关节炎的退行过程中起主要作用。对于有症状的FAI，近年来更多的是通过髋关节镜技术来评估和移除撞击损伤因素，修复损伤盂唇，恢复髋关节在极限运动时的力学范围和结构，消除髋臼前缘撞击因素，缓解年轻患者的髋关节前方疼痛症状。7、髋臼盂唇损伤 髋臼盂唇损伤最常见的临床表现是髋关节前部疼痛。临床上常见的患者抱怨是髋关节前部、外侧、偶感交锁样疼痛，特定扭转部位疼痛加剧。病程较长，多种保守治疗效果不明显。Yamamoto等人报道，80%的关节内髋关节疼痛病例是由于前外上盂唇撕裂引起的。髋臼盂唇的损伤主要是由于髋关节退行性改变（30%）、扭伤创伤（40%）引起。而创伤性髋臼盂唇损伤最常见的情况是股骨近端或髋臼解剖结构异常，当受损盂唇软骨受到反复性、重复性撞击时，产生软骨下骨囊性病变，形成软骨下囊肿。其他原因另外，除了上述原因，临床上导致年轻患者髋关节前方疼痛的原因也包括髋关节滑膜炎类疾病、关节内游离体卡压、圆韧带撕裂等。随着近几年髋关节镜技术的发展，这一类疾病均可通过髋关节镜手术进行探查和治疗。日常生活中我们如何预防？髋关节一旦出现问题，首先会引起疼痛，那么我们应该如何预防和应对髋关节疾病带来的疼痛呢？1、平时要劳逸结合，注意休息，避免过长时间的行走或负重、髋关节冲撞性运动，防止和避免生活中不经意的扭伤动作。2、髋关节疼痛要引起大家重视，尽早到正规医院，寻求专业髋关节外科医师进行诊断和治疗，千万别盲目自行服药，以免出现药物副作用发生关节性病变。3、注意关节局部保暖，气温降低时，要及时添加衣物，以免髋关节受凉。如果本来就患有关节炎，可适当多穿点衣裤以防复发。4、适当锻炼平时应适时补钙，适当锻炼，可有助预防关节炎。需要注意的是，爬山、下蹲等活动要少做，这些都会不同程度上磨损关节。5、保证饮食均衡保证每天摄入足够的热量，控制脂肪摄入。适宜吃高蛋白、易消化的食物，例如鸡蛋、瘦肉和大豆制品。多吃富含维生素C的新鲜蔬菜和水果。饮食应注意清淡，不吃生冷食物。此外，要多饮温开水，预防感冒。

导读：日常髋关节疾病门诊中，我们更多见到把髋关节疼痛模糊诊断为髋关节滑膜炎、髋关节筋膜炎、髋关节积液等。因为大多数医疗机构或门诊缺乏单侧髋关节MR、髋关节造影的影像诊断手段，所以往往导致患者第一时间无法有效诊断，使其反复就诊，临床症状迁延难愈，病程较长，进而失去治疗的信心！今天，我们来介绍一下髋关节盂唇损伤/撕裂的短暂性运动治疗康复方式。我们知道，髋关节盂唇通过加深髋臼的覆盖并提供髋关节密封环境，有助于髋关节的稳定性。骨形态异常，例如股骨髋臼撞击（FAI）或髋臼发育不良以及髋关节功能障碍是增加髋关节盂唇负荷的因素。临床上，腹股沟疼痛和关节不稳定可能由髋臼盂唇损伤引起。髋关节盂唇损伤/撕裂引起的疼痛也有很多种，从无痛到非常疼痛。当髋关节疼痛症状开始影响我们日常活动时——比如爬楼梯、散步或锻炼身体时，这时候就需要探索一个适合自己的缓解疼痛的方法。而对于恢复髋关节盂唇功能的患者来说，最好、最容易接受的治疗方案就是保守治疗、口服药物等非手术治疗。但是从客观角度来讲，针对于盂唇撕裂的治疗方案还是要根据严重程度、临床症状、影像学检查等综合评估制定，症状严重无法通过保守治疗恢复，或者保守治疗时间超过3个月的患者，只能通过髋关节镜手术来修复和重建盂唇撕裂部分。什么是髋关节盂唇撕裂髋臼盂唇是髋臼窝周围的软骨纤维边缘，其对维持髋关节的正常功能非常重要。它加深髋臼对股骨头包容面积，同时将股骨头保持在髋臼内，为髋关节提供了进一步的稳定。髋臼盂唇有助于密封髋关节，从而维持关节内的液体压力，并为整个关节软骨提供营养。如果没有髋臼盂唇完整的密封作用，早期退行性关节炎的风险会明显增加。这也是为何提倡一旦发现盂唇损伤，建议早期接受合理治疗的必要性。髋臼盂唇受损也会导致髋关节旋转中心的移动，这种类型的变化会增加对股骨头的冲击和载荷，加剧股骨头软骨退变。另外，髋关节盂唇撕裂可以在盂唇环的任何一点上形成，最常见的是在前外侧，11点-3点位置。 撕裂程度可以从轻微磨损到完全移位的撕裂不等。以前，髋关节盂唇撕裂经常容易出现误诊，由于先进影像学技术及诊查水平提高，我们才发现盂唇撕裂在髋关节疼痛患者中占很大比例。髋关节盂唇撕裂的临床症状患者最初都是因为髋关节腹股沟的位置疼痛/臀部疼痛就诊，而骨盆X线片或者双髋磁共振（MR）虽然能很好显示骨骼形态和髋关节腔内情况，包括关节腔积液、股骨头坏死，但是，请切记——双侧髋关节MR,并不能很好显示髋关节内细节问题，包括髋臼盂唇损伤、盂唇撕裂的显影。所以，一旦出现髋关节腹股沟部位、髋关节前方疼痛，同时有相应髋臼盂唇损伤、盂唇撕裂的体征，建议行单侧髋关节MR检查，明确诊断。髋关节盂唇撕裂最常见的主诉是髋部前方/周围疼痛。这种疼痛有时会导致抬腿时感到无力，难以平衡或进行单腿活动，如爬楼梯、步行或跑步。同时可伴有其他常见症状有：抬腿时髋部前部剧痛、旋转腿时疼痛、髋部或臀部深痛、髋部活动受限或弹响声、腹股沟或大腿痛、疼痛或麻木辐射到大腿和膝盖外侧。另一方面，临床上因为患者髋关节周围疼痛，往往会影响到腰骶部、臀部、下腰部等部位，使其上述部位出现不同程度疼痛，所以患者更多以为自己是腰部问题或者髋周软组织肌肉问题（筋膜炎）导致，进而导致治疗方向错误，治疗效果不好，病程反复，迁延难愈。什么情况容易导致盂唇撕裂盂唇撕裂的一个常见损伤机制是髋关节扭转暴力，包括间接扭转和直接扭转。日常生活中，导致盂唇损伤原因众多，包括直接直接扭转暴力损伤，譬如包括机滑倒或摔倒伴或不伴髋关节脱位，这是导致盂唇损伤\撕裂的已知原因。另外，日常活动中经常性重复动作的时候，比如踢腿，跳跃，甚至挥杆的时候，扭转髋关节同时容易造成盂唇损伤。这类损伤可以是急性的，也可以是长时间的磨损。同时肌肉力量失衡也会导致盂唇撕裂，随着时间的推移臀肌的无力，会导致髋关节和盂唇的负荷分配不当。 除此之外，患者髋关节存在明确髋臼撞击征FAI、DDH/临界DDH、退行性病变，也被认为是盂唇损伤或盂唇撕裂的明确致病因素。在这些情况下，疼痛通常会逐渐发展，并随着时间的推移而加剧。在这些隐匿性病例中，重复性局部应力损伤被认为是盂唇损伤\撕裂的的主要原因。短暂性运动康复缓解疼痛当我们出现髋关节周围疼痛，并通过骨科专科医师明确诊断出现髋关节盂唇撕裂时,我们应该寻求专业医师，根据自身盂唇撕裂的大小、面积、患者具体的的年龄、体重、生活方式、运动习惯来制定个体化治疗方案：包括保守和髋关节镜手术治疗。1、首先应改变生活方式：日常生活中尽量减少比如负重、爬楼、深蹲、关节过度屈曲旋转等动作，进而减少髋关节撞击，降低盂唇局部应力风险。2、应进行药物的辅助治疗：短期内可以口服消炎镇痛类、营养关节软骨类药物，也可在髋关节周围配合使用外用膏药，缓解局部疼痛症状。3、短暂性运动康复治疗：通过髋关节周围的肌肉力量的康复训练，提升髋关节稳定性，提升关节的活动范围，给盂唇愈合提供一个良好的环境。当通过个体化的保守治疗两个月左右无效时，可考虑进行手术治疗。短暂性运动康复治疗包括：1.髋屈肌伸展运动 ：(1)膝跪在地上，可以在膝盖下垫一个小垫子。(2）此时将肩膀、臀部和膝盖齐平。(3)轻轻地将体重向前倾，使你的臀部超过左膝，这时候应该感到左髋前部有拉伸的感觉。(4)保持大约30秒，然后重复几次。 2.四字拉伸运动：(1)仰卧。(2)膝盖向上抬起，双脚平放。(3)左腿向体侧弯曲，将脚踝跨过右膝。(4)双手环绕右大腿，轻轻向胸部拉30秒。(5)换另一边重复。3.臀桥支撑：(1)以仰卧姿势开始，膝盖弯曲，双脚平放，双手放在身体两侧，手掌朝下。(2)慢慢抬起臀部时，收紧臀大肌，使肩部紧贴地面。(3)臀部抬起保持5秒钟。(4)慢慢将臀部降至地面，要全程保持臀大肌收缩。(5)重复这些步骤8到10次。4.髋关节蚌式开合：(1)侧卧，髋部和膝盖微微弯曲，保持姿势舒适。(2)双膝应该叠放在一起。(3)双脚保持不动，只抬起膝盖，就像是一个开口的蚌。(4)这时候应该感觉到臀部外侧的肌肉活动。(5)保持几秒钟，然后放松休息。(6)必要的时候可以在双膝之间加上阻力带以增加活动强度。5.侧卧抬腿运动：(1)侧卧，身体成直线，将上侧腿部上抬。(2)要保证脚尖朝前。(3)同样为了增加强度可以在膝盖或脚踝上加一条阻力带。 6.保加利亚箭步蹲：这个动作可以集中训练站立侧单腿股四头肌发力能力，但是任何有下肢损伤的人都不建议进行这个动作。(1)从站在一个台阶前面开始，向前迈出一步。(2)将后腿抬起，放在台阶或高处。(3)下蹲成弓箭步，然后再向上站起。     河南省洛阳正骨医院（河南省骨科医院）髋关节外科，刘立云髋关节镜、人工髋关节置换团队。团队研究方向及诊治疾病范围：人工髋关节的置换及翻修；髋关节撞击综合征（髋臼撞击征）FAI、盂唇损伤、盂唇撕裂、臀肌挛缩（弹响髋）髋关节镜治疗；股骨头缺血性坏死阶梯保髋治疗；髋关节周围骨折；髋关节积液和各种髋关节疼痛的分层治疗。咨询电话：18538228639

概述虽然“伯尔尼髋臼周围截骨术”已经成为治疗有症状的DDH患者的主流手术方式，但是，针对DDH患者盂唇损伤的治疗尚未引起足够的重视。盂唇损伤在DDH患者中很常见。而盂唇在维持髋关节生物力学方面起着重要作用，包括增加关节稳定性，负重，维持中央间室密封。完整的盂唇对于关节液流动的适当调节是必要的，功能良好的盂唇可以保持髋关节正常的静水压力，这对软骨健康至关重要，因此，盂唇的密封作用可以保护关节软骨，盂唇损伤后会引起关节软骨退变。理论上讲，PAO手术时同时进行盂唇修复可以改善远期关节功能。我们团队的短期随访研究发现，PAO手术联合髋关节镜下盂唇修补可以改善短期内关节功能，并无额外手术风险增加。与单独进行PAO手术相比，PAO手术联合髋关节镜下盂唇修补或许可以更好的改善远期关节功能。典型病例患者，女，33岁，左髋疼痛2年。       术前查体及评分：左髋腹股沟区压痛（+），伸屈0-120°，伸直内旋30°，外旋40°，FADDIR征（+），FABER征（+），iHOT-33:69.4, mHHS:78。      术前影像学检查：治疗方案：髋镜下盂唇修补，同时进行伯尔尼髋臼周围截骨术。一次麻醉手术，同时解决髋臼对股骨头覆盖不良和髋臼盂唇损伤两个问题。

髋关节镜手术是一种先进的外科手术方法，能够让医生直接观察髋关节内部，而无需进行大的切口。这项微创手术技术虽然没有膝关节镜和肩关节镜常见，但其已经广泛应用于诊断和治疗各种髋关节问题。髋关节是典型的球窝式关节。窝部由骨盆髋臼构成，球部则是股骨头。关节表面覆盖着一层叫做关节软骨的光滑组织，有助于骨骼之间轻松滑动。关节周围有强健的纤维软骨环绕，称为盂唇，有助于深化臼窝，增强关节稳定性。关节被韧带围绕，形成关节囊，使关节保持稳定。关节囊下表面有一层称为滑膜的软组织，可以分泌润滑髋关节的滑液。如果你的髋关节疼痛状况无法通过保守治疗（如休息、物理治疗、口服抗炎药物或关节腔药物注射）得到缓解，医生可能会推荐进行髋关节镜手术。髋关节镜手术能够减轻许多因疾病导致的髋关节盂唇、关节软骨或关节周围其他软组织损伤所引发的疼痛。许多疾病，如股骨髋臼撞击症（FAI）、髋臼盂唇撕裂、髋关节滑膜炎、弹响髋等，都可通过该手术得到治疗和缓解。在髋关节镜手术中，外科医生将一台名为关节镜的小型摄像头插入髋关节。摄像头会将图像显示在视频监视器上，医生便可以利用这些图像指导微型手术器械。由于关节镜和手术器械都很细小，因此手术只需进行非常小的切口，而不是开放手术所需的较大切口。这样可以减轻病人的疼痛和关节僵硬，并且通常可以缩短康复时间和恢复到日常活动的时间。髋关节镜手术的并发症并不常见。手术中对髋关节的牵引可能会暂时拉伸神经，导致腹股沟区域的麻木，但这通常是暂时的。感染和深静脉血栓的风险也很小。术后短暂恢复即可出院，该手术在很多地方特别是国外为日间手术。手术后，你可能需要使用拐杖或助行器辅助步行一段时间（一般根据情况4到6周），并可能需要短期内使用药物来缓解疼痛。手术医生会根据你的手术情况制定康复计划。许多人在髋关节镜手术后能够完全恢复，并无限制地参与活动。然而，对一些人来说，可能需要改变生活方式（如从高强度的锻炼活动，如长跑，减为低强度的锻炼活动，如游泳）以保护关节。少数情况下，损伤可能太严重以至于无法完全逆转，手术存在不成功的可能。随着外科技术的进化，髋关节镜手术在诊断和治疗髋关节疾病方面的作用将越来越大。这为更多患者提供了微创、高效和安全的治疗选项，为健康的髋关节未来铺平了道路。如果您或您的亲朋好友为髋关节相关的疾病所困扰，不妨咨询我们了解更多相关的解决办法。

在前一篇科普文章中，我们揭示了髋关节疼痛的基本情况。在这一篇文章里，我们将更系统地总结髋关节疼痛的不同病因，以便为大家提供全面参考。了解髋关节疼痛的潜在原因对于精确诊断和有效治疗是至关重要的。专业的骨科医生和康复治疗师通常会依据疼痛的性质、发生位置、伴随的症状等多方面因素，进行全面的评估和诊断。在好大夫平台上，我们致力于为您提供丰富而深入的关于髋关节疼痛的信息和资源。若您或您的亲人正在面临这一问题，请不要犹豫，及时与我们的医疗专家取得联系，共同探寻适合您的解决方案。