Case DisscusionBy Group Group 2013-07-112011-06-02History nMale, 28 years oldnHip painnNo laboratory examination Final Diagnosisnbilateral sacroiliitis nseronegative spondyloarthropathy involve bilatreal hip jointnsynovial cyst at the front margin of articular ASnmainly young adults, mostly male nage:10 to 40 years old, average 25nhip involvedone-third of patients with ASnHLA-B27 positive 90% naxial skeletal : bilaterallynperipheral arthritis :asymmetrically ASnconventional radiographsntwo typical featuresnconcentric osteoproliferation with osteophytes around the femoral necknerosions of the acetabulum ASnconventional radiographsnothersnsclerosisnsynovitis ; enthesitisnosteophytosis njoint space narrowing concentric ,uniform njoint effusionnsubchondral bone marrow edema nperiarticular fat depositions DDXnRheumatoid arthritis (RA)nTuberculosis (TB) RAnautoimmune disorder of unknown etiologyncharacteristicnsymmetricnerosive synovitisnsometimes multisystem involvementnhip involved5to15%nmainly women RAnclinical symptomnpainnswellingnstiffness nmotion impairmentnlaboratory testsnrheumatoid factor(+)nelevated ESR and CRP RAnimaging appearancensynovitisnthickening of soft tissue nosteoporosisnsubchondral cyst formationnhomogeneous narrowing of articular spacenerosion of cartilagenacetabulum and head of femur both involved RAnimaging appearancenMRInearly stage (rich vessels of pannus)nT1WIlow signalnT2WIhigh signalnlate stage (increased fabre composition)nT1WIisosignalnT2WIisosignal RAnsynovial cystrare TBnpathogenesis hematogenous disseminationn15% cases of osteoarticular tuberculosisncommon agethe second and third decadesnthe most common sitevertebral tuberculosis TBnlesions on the acetabular side progress less rapidly than lesions on the femoral side TBnclinical symptomncommon symptomnjoint symptomnpainnfixed deformities of the hipnpainful limitation of movementnmuscle wastingnregional lymph node enlargementnform of cold abscess with or without sinusesnpathologic dislocation of the hip TBnimaging appearancenthickening of the synoviumnsubchondral and marginal bony erosion neffusionnloss of joint spacenperiarticular abscessnjuxta-articular osteoporosis TBnhip dislocation uncommon TBntuberculous bursitisrarencommon sitetrochanteric regionhip joint arthritisclinical symptom、agegender、laboratory examinationHLA-27(+)ASRF(+)RATubercle bacillus TBimaging appearanceenthesitis、osteophytosis、combined SIJ and spine changesASobvious synovitispolyarticular、bone erosion、uniform narrowingRAmonoarticularnonuniform narrowing bone destructionTBFinal diagnosiscombinationMade by chaichaoRAJoint TBPVNSGouty Joint involvementPolyarticularSymmetricalmonoarticularmonoarticularKnee，80%The first metatarsophalangeal jointsequestrum_+_cold abscess /sinus tract _+_Reactive sclerosis_+_+OsteoporosiswideLocal(Periarticular )_joint space narrowinguniformnonuniform_（late）_