[Agreement between ultrasound-detected inflammation and clinical signs in ankles and feet joints in patients with rheumatoid arthritis].

OBJECTIVE: To investigate the agreement between clinical signs (tenderness and/or swelling) in ankles and feet joints and ultrasound findings in patients with rheumatoid arthritis (RA).
METHODS: RA patients with at least 1 tender and/or swollen joint in bilateral ankles and metatarsophalangeal (MTP) joints detected by physical examination were enrolled and underwent ultrasound examination by greyscale (GS) and power Doppler (PD) mode. The agreement between clinical signs and ultrasound-detected inflammation (joint effusion, synovitis, or tenosynovitis) was analyzed.
RESULTS: In the study, 113 consecutive RA patients were included, with mean age of (52.5±12.6) years, median duration of 60 (13, 129) months, mean disease activity score in 28 joints based on erythrocyte sedimentation rate [DAS28 (ESR)] of 5.1±1.7, mean disease activity score in 28 joints based on C reactive protein[DAS28 (CRP)]of 4.6±1.5. The tenderness and swelling was most commonly detected in ankles (52.7% and 31.9%, respectively), while GS (+) synovitis was most frequently detectable in MTP2 (34.1%), followed by ankles (32.7%) and MTP1 (27.9%), and PD (+) synovitis was most frequently detectable in MTP1 (14.2%), followed by ankles (12.4%) and MTP2 (10.6%). The prevalence of tenosynovitis was 41.1%, which mostly located in tibialis posterior tendon (22.1% of GS positive and 17.6% of PD positive). The highest prevalence of joint effusion was detected in ankles (9.7%), while that of bone erosion in MTP5 (19%). The overall concordance rate between positive clinical signs and ultrasound-determined joint inflammation was poor in the above joints (κ < 0.2, P < 0.05), in which swelling had the highest κ coefficient with ultrasound-determined joint inflammation in ankles (κ=0.225, P < 0.05). Moreover, swelling had the highest κ coefficient with synovitis in ankles (κ=0.231, P < 0.05).The concordance between tenosynovitis and signs in ankles was also poor (κ < 0.20, P < 0.05). There was no significant agreement between joint effusion and clinical signs (P > 0.05).
CONCLUSION: The overall concordance between clinical signs and inflammation on ultrasound was poor in ankles and feet joints. Tenderness and swelling was more common in ankles, while more lesions were detected by ultrasound at MTP joints. Ultrasound is useful in assessing the lesions besides physical examination in patients with RA.