醫(yī)院骨科課件：骨股頭壞死及軟骨傷

Differentiationof(應(yīng)力性骨折)

SubchondralInsufficiencyFractureFromOsteonecrosisoftheFemoralHeadAJR2010;195:W63-W68

Introduction(1)Itisnecessarytodifferentiatesubchondralinsufficiencyfractureofthefemoralheadfromosteonecrosisofthefemoralhead,becausethesetwoconditionshaveseveraloverlappingcharacteristicsinbothimagingandclinicalappearances.Radiographically,subchondralcollapseisoftenassociatedwithosteonecrosis;however,somecasesofsubchondralinsufficiencyfracturealsoshowsimilarfindings.Oneofthecharacteristicfindingsinsubchondralinsufficiencyfractureistheshapeofthelow-intensitybandonT1-weightedimages:itisgenerallyirregular,serpiginous,convextothearticularsurface,andoftendiscontinuous.Incontrast,inosteonecrosis,thelow–intensitybandisgenerallysmoothconcavetoarticularsurface.Subchondralinsufficiencyfractureprimarilyisreportedinelderlyoverweightwomenwithosteoporosis(骨質(zhì)疏松癥).Ingeneral,theaverageageofsuchpatientsis60years(orolder),andmostofthepatientstendtoshowunilateralinvolvement.Anumberofreportshavecomparedtheimagingorhistopathologicappearanceofosteonecrosiswiththatofsubchondralinsufficiencyfracture;however,fewreportshaveidentifiedusefulclinicalfeaturesforthedifferentiationbetweenosteonecrosisandsubchondralinsufficiencyfractureonthebasisofstatisticalevidenceIntroduction(2)Diagramshowingcriteriafordifferentiatingosteonecrosisfromsubchondralinsufficiencyfractureaccordingtoshapeoflow-intensitybandonT1-weightedlow-intensitybandissmooth,concavetoarticularsurface,andcircumscribesallofnecroticsegmentsInosteonecrosisInsubchondralinsufficiencyfracturelow-intensitybandisirregular,convextoarticularsurface,anddiscontinuous.64-year-oldmanwithhistoryofalcoholabuseandosteonecrosisobtainedattimeofonsetofpainshowsbothcrescentsignandcollapseoffemoralheadatsuperolateralportion(arrows

showsdiffuselowsignalintensityinfemoralneckatlateralportionandintertrochantericarea.Low-intensitybandonT1-weightedimageisconcavetoarticularsurface(arrows

64-year-oldmanwithhistoryofalcoholabuseandosteonecrosisCutsectionofresectedfemoralheadshowszonalpattern(necrotic,reparative,andviablezones).Subchondralfractureline(arrow)correspondingtocrescentsignonradiograph(A)isseen.Histopathologicappearanceofnecroticregion,whichshowsaccumulationofbonemarrowcelldebris,andbonetrabeculaewithemptylacunaebeneathfracturelineareseen75-year-oldwoman,withouthistoryofeithercorticosteroidintakeoralcoholabuse,withsubchondralinsufficiencyfractureFat-saturatedcontrast-enhancedAxialslicesofT1-weightedimageCoronalT1-weightedimageTheshapeofthelow-intensitybandisusefulforthedifferentiationofsubchondralinsufficiencyfracturefromosteonecrosisinpatientswithradiologicevidenceofsubchondralcollapseofthefemoralhead.Clinically,forosteoporoticelderlywomenwithoutahistoryofcorticosteroidintakeoralcoholabuse,adiagnosisofsubchondralinsufficiencyfractureshouldbeconsidered.Finally,thecrescentsignisnotsufficienttodifferentiatesubchondralinsufficiencyfracturefromosteonecrosisincaseswithcollapsedfemoralheadsInconclusion59-year-oldwomanwithacuteonsetofsevererighthippain.Anteroposteriorradiographobtained1weekafteronsetofpainshowsslightsubchondralcollapse(arrow)insuperolateralportionoffemoralhead(A)AJR2002;178:435-437

Anteroposteriorradiographobtained2weeksafteronsetofpainshowsrapidprogressionofsubchondralcollapse.(B)AJR2002;178:435-437

T1-weightedMRimageobtained2.5weeksafteronsetofhippainshowsbonemarrowedemapatterninfemoralheadandmedialaspectofacetabularroof.Notediffuselowsignalintensitywithassociatedserpiginousirregular,verylow-signal-intensitybands(arrows)(c)AJR2002;178:435-437

T2-weightedMRimageshowsdiffusehighsignalintensityinsameareaasshownonC.However,proximalsuperiorportionoffemoralheadshowslowsignalintensity.Notejointeffusion.(D)AJR2002;178:435-437

.Midcoronalcuthistopathologicsectionshowsnotchedlinearshapedzoneofwhitishgreytissue(arrows)undercartilageflap.Noevidenceofopaqueyellowwedge-shapedosteonecrosisisseen.(E)AJR2002;178:435-437

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