Power Doppler ultrasonography of symptomatic rheumatoid arthritis ankles revealed a positive association between tenosynovitis and rheumatoid factor.

The aim of this study was to characterize the pathological conditions of symptomatic ankles in patients with rheumatoid arthritis (RA) using power Doppler sonography (PDS). We analyzed 17 consecutive ultrasonography (US) records of RA patients with symptomatic ankles who underwent B-mode ultrasonography (BUS) combined with PDS of their ankles in our department because of clinical need. Correlations between US findings and clinical and serological data were assessed. The diagnostic capabilities of BUS and PDS were also compared. Common US findings were talocrural synovitis (76%), subtalar synovitis (71%), and talonavicular synovitis (59%). Tenosynovitis around the ankle was detected in ten patients (59%), including several cases of tenosynovitis of tibialis posterior (41%) and tenosynovitis of peroneus longus and brevis (35%). Achilles tendon enthesitis was detected in six patients, and retrocalcaneal bursitis was detected in five. Compared with BUS, PDS offers demonstrably superior diagnostic capability for the detection of rheumatoid ankle diseases, especially subtalar joint synovitis and peroneal tenosynovitis. Rheumatoid factor (RF) levels were significantly higher in patients with tenosynovitis than in patients without tenosynovitis. PDS is an excellent modality for diagnosing both intra- and extracapsular synovitis in rheumatoid ankles. Using PDS, we found positive association between ankle tenosynovitis and RF levels in RA patients.