Ultrasound examination of symptomatic ankles in shorter-duration rheumatoid arthritis patients often reveals tenosynovitis.

OBJECTIVES: This study investigated the frequency and characteristics of various pathologies in symptomatic ankles in RA patients, especially early RA patients, using power Doppler ultrasound (PDUS).
METHODS: We analysed consecutive records of 100 ankles in 74 RA patients who had PDUS scans of symptomatic ankles in our department. The association between US findings and disease duration was analysed.
RESULTS: Joint synovitis of ankles including in talocrural, subtalar and talonavicular joints was detected in 56 ankles. Ankle tenosynovitis was detected at the medial recess in 46 ankles, at the lateral recess in 29 ankles, and at anterior aspects in 10 ankles (in 61 ankles overall). Achilles tendon involvement including retrocalcaneal bursitis, Achilles tendon enthesitis, tendonitis, and paratendonitis was detected in 39 ankles. Disease duration was significantly shorter in the ankles with tenosynovitis than in those without tenosynovitis (11.4±21.6 vs. 32.0±58.3 months, p=0.039). Disease duration was even more significantly shorter in ankles with isolated tenosynovitis (i.e., ankles with tenosynovitis but without joint synovitis, n=30) than in all other ankles (5.9±8.7 vs. 25.2±47.8 months, p=0.0016). Tenosynovitis and isolated tenosynovitis, especially, were significantly more common in early RA ankles (disease duration <6 months) than in those with established RA (p=0.0357 and p=0.0236, respectively).
CONCLUSIONS: Tenosynovitis and especially isolated tenosynovitis are frequently detected by US in symptomatic ankles of early RA patients. US examination of ankles in early RA patients should include scans of the medial and lateral recess to enable early detection of ankle tenosynovitis.