股骨頭壞死影像學(xué)表現(xiàn)

WordsSubchondralInsufficiencyFracture：軟骨下不全骨折OsteonecrosisoftheFemoralHead：股骨頭壞死Convex凸ncavity凹第1頁，共30頁。軟骨下不全骨折（Subchondralinsufficiencyfracture,簡稱SIFs）

1、軟骨下機能不全性骨折是非外傷性的一種骨折。2、最常見的病因：骨質(zhì)疏松，不常見的病因是骨質(zhì)軟化癥或骨不全癥、甲狀旁腺功能亢進和類風(fēng)濕性關(guān)節(jié)炎等。3、發(fā)病原理：正常軟骨可忍受正常的生物機械應(yīng)力，當(dāng)由于上述病因變得軟弱時，可出現(xiàn)軟骨下骨折，并發(fā)展為軟骨下萎陷，為此需認識此病作出早期診斷，多數(shù)患者經(jīng)保守治療后可自愈。

第2頁，共30頁。OBJECTIVEThepurposeofthisarticleistoverifythehypothesisthatosteonecrosisandsubchondralinsufficiencyfractureofthefemoralheadcanbedifferentiatedonthebasisoftheirappearanceonMRI.第3頁，共30頁。SUBJECTSANDMETHODS1BetweenMay1998andFebruary2009,wereviewed30consecutivehipsin30patients,60yearsoldorolderatthetimeofonsetofhippain,withradiologicevidenceofsubchondralcollapseofthefemoralheadandwithbothMRimagesandhistologicresultsavailable.第4頁，共30頁。SUBJECTSANDMETHODS2Thepatientsweredividedintotwogroupaccordingtotheshapeoflow-intensitybandsonT1-weightedimages.Thefirstgroupshowedconcavityofthearticularsurface,whichischaracteristicofosteonecrosis,andthesecondgroupshowedanirregularconvexityofthearticularsurface,whichischaracteristicofsubchondralinsufficiencyfracture.第5頁，共30頁。AInosteonecrosis,low-intensitybandissmooth,concavetoarticularsurface,andcircumscribesallofnecroticsegments.BInsubchondralinsufficiencyfracture,low-intensitybandisirregular,convextoarticularsurface,anddiscontinuous.第6頁，共30頁。RESULTSSixteenhips(53.3%)showedevidenceofosteonecrosis,and14(46.7%)showedevidenceofsubchondralinsufficiencyfracture,whichwasconsistentwiththecorrespondinghistopathologicdiagnoses.Inallcasesofosteonecrosis,thepatienthadahistoryofeithercorticosteroidintakeoralcoholabuse.Amongpatientswithsubchondralinsufficiencyfracture,theproportionofwomenwassignificantlyhigherthanthatamongpatientswithosteonecrosis.Acrescentsign(subchondralfracture)waspresentradiographicallyinabouthalfofallcasesinbothgroups.第7頁，共30頁。TABLE1:ClinicalCharacteristicsofPatientsWithOsteonecrosisor

SubchondralInsufficiencyFracture第8頁，共30頁。CONCLUSIONTheresultsofthepresentstudysuggestthattheshapeofthelow-intensitybandonMRIisusefulforthedifferentiatingsubchondralinsufficiencyfracturefromosteonecrosis.Inaddition,amongosteoporoticelderlywomenwithoutanyhistoryofcorticosteroidintakeoralcoholabuse,adiagnosisofsubchondralinsufficiencyfractureshouldbeconsidered.第9頁，共30頁。64-year-oldmanwithhistoryofalcoholabuseandosteonecrosis.A,Anteroposteriorradiographoflefthip(Singhindexofseverityofosteoporosis,gradeV)obtainedattimeofonsetofpainshowsbothcrescentsignandcollapseoffemoralheadatsuperolateralportion(arrows).第10頁，共30頁。B,CoronalT1-weightedimage(TR/TE,470/15)showsdiffuselowsignalintensityinfemoralneckatlateralportionandintertrochantericarea.Low-intensitybandonT1-weightedimageisconcavetoarticularsurface(arrows).第11頁，共30頁。“線樣征”位于股骨頭頸前上部病灶周圍多呈空間錐形分布,錐尖指向股骨頭基底部或股骨頸。Glimcher認為修復(fù)開始后,肉芽組織自股骨頸或股骨頭基底部向死骨區(qū)爬行。肉芽組織到達并吸收骨皮質(zhì)時,皮質(zhì)承載力減弱。在重力作用下自此皮質(zhì)薄弱區(qū)于松質(zhì)骨內(nèi)產(chǎn)生多條微骨折線,因應(yīng)力作用微骨折線多位于股骨頭前上部周圍。肉芽組織在微骨折處大量增生堆積、吸收壞死骨小梁并于外圍大量成骨,從而形成T2WI上的“雙線癥”。第12頁，共30頁。D,AxialsliceofT1-weightedimage(500/15)showsthatlow-intensitybandcircumscribesallofnecroticsegments(arrows).第13頁，共30頁。E,Cutsectionofresectedfemoralheadshowszonalpattern(necrotic,reparative,andviablezones).Subchondralfractureline(arrow)correspondingtocrescentsignonradiograph(A)isseen.第14頁，共30頁。新月征形成機制因皮質(zhì)斷裂塌陷時,關(guān)節(jié)軟骨在一段時間內(nèi)尚保持完整,形成軟骨下負壓。股骨頭體液內(nèi)氣體在負壓作用下溢出并進入囊腔。第15頁，共30頁。第16頁，共30頁。F,Histopathologicappearanceofnecroticregion,whichshowsaccumulationofbonemarrowcelldebris,andbonetrabeculaewithemptylacunaebeneathfracturelineareseen.(HandE,×40)第17頁，共30頁。G,Thereisrepairtissueinreparativezone,includingvasculargranulationtissue,fibroustissue.(HandE,×20)第18頁，共30頁。Fig.3—75-year-oldwoman,withouthistoryofeithercorticosteroidintakeoralcoholabuse,withsubchondralinsufficiencyfracture.Anteroposteriorradiographoflefthip(Singhindexofseverityofosteoporosis,gradeV)obtainedattimeofonsetofpainshowsbothcrescentsignandcollapseoffemoralheadatsuperolateralportion(arrows).第19頁，共30頁。Thefrequencyofthecrescentsigninthesubchondralinsufficiencyfracturegroupwassimilartothatinosteonecrosisgroupinthecurrentstudy,thusindicatingthatthecrescentsignisnotsufficienttodifferentiateosteonecrosisfromsubchondralinsufficiencyfracture.第20頁，共30頁。B,CoronalT1-weightedimage(TR/TE,470/25)showsdiffuselowsignalintensityinfemoralheadandneck.Low-intensitybandisparallelto

subchondralboneendplate(arrows).Thelow-intensitybandonT1-weightedimagesinsubchondralinsufficiencyfracturecorrespondshistologicallytothefracturelineandassociatedfracturerepairtissue.Therefore,theshapeofthelow-intensitybandgenerallytendstobeirregular,disconnected,andconvextothearticularsurface.第21頁，共30頁。D,AxialslicesofT1-weightedimage(500/15)showlow-intensitybandmainlyinanteriorregion,whichisinterruptedinmiddle(arrows).第22頁，共30頁。E,Fat-saturatedcontrast-enhancedMRI(fromimageshowninD)(605/14)inwhichpartofproximalportionbeyondlow-intensitybandshowscontrastenhancementindicatingperfusion(arrows).第23頁，共30頁。F,Cutsectionofresectedfemoralheadshowssubchondralfractureline(blackarrow)andwhitishlinearshapedareabeneatharticularcartilage(whitearrow).第24頁，共30頁。G,Bandregionhistopathologicallycorrespondstofracturecallus,reactivecartilage,andgranulationtissue.(HandE,×40)第25頁，共30頁。第26頁，共30頁。Limititions樣本量小對于軟骨下不全骨折早期表現(xiàn)，如軟骨下水腫，由于在平片上未見異常，未被納入。僅4例進行了增強MR檢查。第27頁，共30頁。真愛生命，拒絕酒精第28頁，共30頁。統(tǒng)計學(xué)方法StatisticalanalyseswereperformedusingFisher’sexact

probabilitytestwithregardtosex,ahis