BackgroundHip joint (HJ) involvement is one of the most common extra-axial manifestations of ankylosing spondylitis (AS).ObjectivesTo correlate clinical manifestations of coxitis with the ultra-sound findings in AS patients.Methods224 consecutive AS patients (mean age 33,2±14,2 y) meeting 1984 modified N-Y criteria and hospitalised in V.A. Nasonova Research Institute of Rheumatology with hip pain were evaluated. Patients’ mean age at the onset of the disease was 26,3±20,3 y., 93% of them were HLA-B27-positive. Median AS duration was 57 [12–444] months, the BASDAI score was 5,7±3,1. The diagnosis of coxitis was based on clinical signs and symptoms, such as inguinal pain and/or limitation in the range of hip motion (ROM) at the time of patients’ admission to the clinic. All patients (regardless current complaints) were subjected to ultrasound (US) examination of the HJ (Sono Diagnost 360 (Philips)) using linear (7,5 MHz) and convex (5,0 MHz) transducers. A neck capsular pattern (NCP – the distance between the signals from inner surface of the femoral neck and the joint capsule) more than 7 mm was used as the US criterion, verifying the clinical diagnosis of coxitis.ResultsThe US criterion of coxitis was found in 119 (53%) out of 224 patients, and two groups of pts were analysed based on NCP values with 7 mm threshold.ParametersP
Group1 without US signs of coxitis (n=105)Group2 US confirmed coxitis (n=119)
Gender(f/m), n79/2677/400,01AS duration, mo, Me[25%, 75%;]4319;8010224;1200,0006BASDAI, Me25;754,12,6; 5,55,24,2; 6,70,0001BASFI, Me25;752,42,0; 3,83,42,0; 5,40,0001HLA-B27, n (%)96 (91%)113 (95%)0,4ASDAS (?RP) ??[25;752,82,0; 3,83,52,6; 3,80002ESR, mm/h, Me [25%; 75%]105; 25258; 350001CRP, mg/mL, Me [25%; 75%]10,53,8; 28,523,04,9; 43,50,06Peripheral arthritis%38 (36%)28 (30%)0,06ConclusionsUS criterion of coxitis, i..e, increased NCP, was found in 53% of patients with clinical AS manifestations. Patients with US-confirmed coxitis demonstrate more active disease with greater functional impairment and longer history of AS, as compared to AS population without US signs of hip involvement.Disclosure of InterestNone declared