AB1221 The association between synovitis in the foot on joint ultrasonography and clinical parameters in patients with rheumatoid arthritis

Background Treatment of rheumatoid arthritis (RA) has improved dramatically with the widespread use of biological disease-modifying antirheumatic drugs. In this context, the number of RA patients who undergo orthopaedic surgery is reportedly decreasing. However, the number of RA patients who undergo foot surgery is increasing. Joint ultrasonography has been used for early diagnosis and disease activity assessment in RA, allowing visualisation of synovitis. However, few detailed studies or evaluations of clinical parameters related to synovitis in the foot have been performed. Objectives This study investigated the association between synovitis in the foot as observed on joint ultrasonography and the degree of disability on the health assessment questionnaire (HAQ) in RA patients. Methods The study included 79 outpatients (101 feet) with RA. Patients who had undergone surgery were excluded. The mean age was 66.0 years (24–92 years), and the mean disease duration was 13 years and 5 months (ranging from 1 month to 49 years). Joint ultrasonography was performed by the same examiner using the same diagnostic instrument in the same room. Synovitis was defined as a power Doppler score of ≥Grade 1. The scanning sites were forefoot (metatarsophalangeal joints of toes 1–5), metatarsus (calcaneocuboid and talonavicular joints), and hindfoot (talocrural and subtalar joints, peroneal tendon, posterior tibial tendon). The presence or absence of synovitis was evaluated at each site, and the association with the HAQ score was examined. Results Synovitis was detected in the forefoot of 40 feet (39.6%), in the metatarsus of 34 feet (33.7%), and in the hindfoot of 63 feet (62.4%). Patients with synovitis in the forefoot (PD+: 0.41±0.1, PD-: 0.80±0.1, p=0.018) and hindfoot (PD+: 0.52±0.1, PD-: 0.86±0.1, p=0.043) had significantly lower HAQ scores. Conclusions Given that assessment of foot impairment is not included in the disease activity index for RA, there may be a delay in diagnosis of foot lesions. Our results showed that patients with synovitis in the forefoot and rearfoot had lower HAQ scores (disability measure), suggesting that increased physical activity may be associated with increasing incidence of synovitis in the foot. The ability of RA patients to perform activities of daily living may have improved with advances in pharmacotherapy, leading to increased physical stimulation, resulting in an increased incidence of synovitis of the foot. References [1] Brown AK. Arthtitis Rheum58(10); 2958–67: 2008 [2] Wakefield RJ. Ann Rheum Dis63; 382–5: 2004 Disclosure of Interest None declared