Objective To evaluate the clinical and imaging characteristics of osteoid osteoma in femoral neck and to improve diagnostic accuracy of this disease.Methods Twenty-one patients (18 males and 3 females,age,7-26 years,median age,13 years) with pathologically proven osteoid osteoma of the femoral neck were retrospectively analyzed for their clinical profile and radiologic features.CT and X-ray examinations were performed in all patients,10 of them pefformed post-contrast CT scan and 4 of them performed MRI examinations.Results Nineteen patients had hip pain (pain worse at night in 11,and 8 received salicylates treatment with good response),and 2 patients only with intermittent claudication.The duration ranged from 2 months to 54 months (median duration 12 months).X-ray: Nidus was seen on plain film in 10 cases,18 cases showed different degrees of bone sclerosis of the nidus.CT: Nidus was demonstrated in all cases.Among them,8 were intracortical,6 were subperiosteal,7 were endosteal.Twenty cases showed different degrees of bone sclerosis of the nidus-extra-articular anteromedial cortical surface of the femur neck.Nineteen cases showed vascular groove sign.MRI: Nidus was seen in 4 cases.Bone sclerosis was low signal on all sequences.Three cases had joint effusion,4 cases had bone marrow edema,and 2 cases had synovial thickening.Conclusions Although osteoid osteoma of femoral neck has non-specific clinical features,the radiographic findings are usually typical.The nidus of osteoid osteoma is often located within the joint.Bony sclerosis occurs at the area of extra-articular anteromedial cortical surface of the femur neck.CT examination remains an optimal method to identify the nidus.

Objective To investigate whether prolonged the interval of tumor necrosis factor (TNF)-α inhibitors (TNF-i) injection could continuously improve inflammatory biomarkers and imaging changes of sacroiliac joint and spine in spondyloarthritis (SpA).Methods A total of 154 SpA patients were included and 95 of them received TNF-α inhibitor therapy.TNF-i used in this study included etanercept,infliximab and adalimumab.The dose of etanercept was gradually reduced from 50 mg per week to every two weeks,every three weeks and then per month.The infusion of Infliximab was reduced from 4 mg/kg at 0,2,6 week to every 8 weeks,every 12 weeks and then every 16 weeks.The interval of Adalimumub injection was changed from 40 mg every two weeks to 3 weeks to 4 weeks and then to two months.The levels of inflammatory parameters,bath ankylosing spondylitis disease activity index (BASDAI),bath ankylosing spondylitis functional index (BASFI),ankylosing spondylitis disease activity score (ASDAS),spondyloarthritis research consortium of canada (SPARCC) scores of sacroiliac joint and fat metaplasia,bone erosion,sclerosis and ankylosis changes on magnetic resonance imaging (MRI) were investigated every 3 to 6 months.Radiograhs of spine were assessed by modified stoke ankylosing spondylitis spinal score (mSASSS) scores at baseline and 2 years.Analyses were performed by Paired t-test,Wilcoxon test,Mann-Whitney U test,Kruskal-Wallis and Chi-square test.Results After 3 months of treatment,erythrocyte sedimentation rate (ESR),c reactive protein (CRP),immunoglobulin A (IgA),BASDAI,BASFI,ASDAS and SPARCC scores were significantly lower than those of the baseline [13.00(6.00,31.00) mm/1 h vs 3.00 (2.00,6.00) mm/1 h,Z=-5.61;7.39(2.52,17.90) mg/L vs 1.88(1.21,3.75) mg/L,Z=-5.57;2.89(2.52,17.90) g/L vs 2.27(1.60,2.85) g/L,Z=-4.69;(2.57±1.43) vs (1.17±0.92),t=9.81;17.50(5.00,27.00) vs 4.00(0,11.00),Z=-6.69;2.62(2.02,3.52) vs 1.22(0.92,1.59),Z=-6.96;25.00(10.00,37.00) vs 12.00 (6.00,20.25),Z=-6.68;all P＜0.05].Compared to 3-6 months,SPARCC scores were significantly reduced during 2-3 years in the TNF-i group [12.00 (6.00,20.25) vs 7.00 (3.25,14.75),P=0.02].There were no significant progresses in fat metaplaisa,bone erosions,sclerosis or ankylosis during the follow-up period (61％,57％,x2=0.07,P=1.00;53％,43％,x2=0.40,P=0.75;31％,57％,x2=3.02,P=0.11;14％,7％,x2=0.43,P=0.66).The mSASSS scores were not different between TNF-i group and TNF-i group after 2 years of treatment [2.50 (0,8.00) vs 3.00 (0,8.00),Z=-0.30,P=0.76].Conclusion Prolonged the interval of TNF-i treatment could continuously improve bone marrow edema in SPA,whereas structural damages of sacroiliac joints and spine are not deteriorated.