POS0987 INFLAMMATION OF THE HIP JOINTS IN EARLY AXIAL SPONDYLOATRITIS: DATA ANALYSIS OF VISUALIZATION METHODS

Background: According to epidemiological studies in Russia, the inflammation of the hip joints occurs in half of patients with ankylosing spondylitis (AS). There have been practically no studies devoted to the investigations of coxitis in patients with early axial spondyloarthritis (axSpA). It is still unknown what factors cause the development of coxitis in axSpA; there is no generally accepted algorithm for diagnosing this condition, especially at an early stage. Previous studies have shown that coxitis in patients with AS develops on average 5–10 years after the onset of the disease, some patients already have irreversible changes in the hip joint at the time of diagnosis, and some do not develop coxitis never. Objectives: To compare the clinical manifestations of coxitis with the results of magnetic resonance imaging (MRI), ultrasound (US), and radiography of the hip. Methods: We examined 175 patients (mean age 28.0 ± 5.92 years) with axSpA (ASAS, 2009), with a duration of inflammatory back pain of no more than 5 years, from the CoRSaR cohort. The median duration of the disease was 21 [3–60] months. BASDAI - 4.0 ± 2.0, BASFI - 2.0 [0.4; 3.5]. Among the included patients, 69 (39.4%) had nr-axSpA, and 106 - AS; 87% were HLA-B27 positive. All patients underwent US examination of the hip joint. When synovitis was detected, the patients underwent MRI examination of the hip joint. The increase in the cervical-capsular distance (CCD) more than 7 mm was considered as an ultrasonic coxitis. The median CCD was 7.5 [7.0; 8.2] mm. For coxitis in MRI, osteitis of the head of the hip or acetabulum and synovitis were taken. Radiographic severity of coxitis was determined by BASRI hip. Results: According to the US data, synovitis of the hip joint was detected in 54 from 175 (30.9%) patients. Pain in the hip joint had 33 (61%) patients. There was no correlation between the intensivity of pain and CCD. CCD significantly correlated with laboratory indicators of disease activity, such as ESR (r = 0.34; p Conclusion: In early axSPA: - 30.9% of patients have hip synovitis, and among them, MRI signs of coxitis have 72%, and X-ray coxitis - 13%; - ultrasound synovitis is only confirmed by MRI in 70% of cases; - it seems that the radiological progression of coxitis does not depend on the activity of the disease. Disclosure of Interests: None declared.