AB1160 INVOLVEMENT OF ANKLE JOINTS AND TENDONS IN SYSTEMIC LUPUS ERYTHEMATOSUS: AN ULTRASOUND STUDY

Abstract

Background Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with heterogeneous clinical manifestations. The musculoskeletal involvement is among commonest and earliest symptoms occurring in 95% of patients. The clinical examination of the ankle joints may underestimate the type and distribution of pathological changes. Musculoskeletal ultrasound (US) is a useful diagnostic tool for evaluation of joints and tendons in the majority of inflammatory rheumatic diseases. Objectives The aim of this study is to assess the ankle joints and tendons involvement in SLE patients using US and to correlate the findings with the physical examination, laboratory tests and disease activity scores. Methods Forty consecutive SLE patients were enrolled in the study and underwent clinical evaluation, laboratory tests and bilateral high-resolution US on the same day. Grey-scale and power Doppler (PD) US of the talocrural (TC), subtalar joints (ST), ankle tendons, second and third MCP joints, second and third PIP joints, wrists and second and third MTP joints were performed. Results A total of 720 joints and 800 tendons were examined. US detected inflammatory joint abnormalities were present in 35/40 (87,5%) patients while tenosynovitis was present in 7/40 (17,5%) patients. The most frequently affected were MTP joints (67,5%) followed by MCP(42,5%) and TC joints (40%), wrists (27,5%) and PIP joints (7,5%). The most prevalent pathological US finding was joint effusion.Synovial hypertrophy and positive PD signal were less frequently observed. Effusion in TC joints was present in 40%, synovial hypertrophy in 20% and positive PD in 2,5% of the patients. Only two patients had bony erosions detected.Six out of forty patients (15%) reported pain or swelling in ankle joints and two(33%) of them didn’t have any US abnormalities.As many as 47% of patients without inflammatory joint symptoms had pathological US findings in ankle joints. The most commonly affected tendon was tibialis anterior (7,5% of patients), followed by extensor halluces longus tendon (5% of patients). Conclusion Results of this study show a high prevalence of US verified inflammatory joint changes in SLE patients, while tendon changes were extremely rare. Foot joints were most commonly affected, followed by wrists and ankle joints. It is important to stress that a great number of asymptomatic patients had pathological US findings in ankle joints. From this and previous studies it is clear that US should be used more in the periodical assessment of the musculoskeletal system in patients with SLE.