Background spondyloarthritis (SpA) is characterized by inflammation of spine and sacroiliac joints. Hip involvement is the most frequent extra spinal arthritic manifestation of SpA and may lead to a worse functional outcome.

Objectives The objective of this study was to assess clinical, biological and radiological characteristics of SpA patients with hip disease.

Methods This is a transversal multicenter study, including SpAs patients (satisfying ASAS criteria2009) with hip disease Demographic, clinical, radiographic, and laboratory data were collected and analyzed. Radiographic forms of hip disease were assessed according to Netter classification (early, condensing, destructive, combined and synostosante forms). Radiographic severity was assessed by the modified Stokes Ankylosing Spondylitis Spine Score (mSASSS) and BASRI (Bath Ankylosing Spondylitis Radiologic Index).

Results ninety four patients were evaluated (77men). The mean age was 41.53±11.97 years. The median age at disease onset was 26.23±10.29 years.The mean diagnostic delay was 6.48 years. 46% of patients were smoker. HLA B27 was positive in 50% of cases. A peripheral joint involvement was found in 33% of cases. Extra-articular manifestation was seen in 57% of patients: osteoporosis (16 patients), uveitis (15 patients), psoraisis (10 patients), chronic inflammatory bowel disease (12 patients). 78 patients had bilateral hip involvement and 147 hips were evaluated. The median BASDAI and BASFI scores were respectively 5,4 and 5,5. The mean index of severity for osteoarthritis for the hip (ISH) was 12.24 (±6.84). Patients had an early form of hip disease in 22% of cases, Condensing form in 3% of cases, combined forms in 22% of cases and destructive form in 53% of cases. BASRI-hip score was 1 in 24%, 2 in 49%, 3 in 19% and 4 in 8% of hips. Sacoiliac joint grade was 2 in 17%, 3 in 37% and 4 in 46% of cases. The mean mSASSS score was 15.34±16.22.

TNF inhibitors were indicated in 49% of patients (infliximab 23, Adalimumab 7 and Etanercept 18).31 patients received csDMARDs and 46 NSAID.

Conclusions Our finding confirm previous observation that clinical and radiological hip involvement is associated with a more severe disease with a high activity and pronounced functional impairments.

Disclosure of Interest None declared