Ultrasound Features of the First Metatarsophalangeal Joint in Gout and Asymptomatic Hyperuricemia: Comparison With Normouricemic Individuals.

OBJECTIVE: The first metatarsophalangeal (MTP1) joint is frequently affected in gout. The aim of this study was to identify ultrasound features of the MTP1 joint in people with gout and people with asymptomatic hyperuricemia compared with normouricemic controls.

METHODS: Participants with gout (n = 23) and asymptomatic hyperuricemia (n = 29), and age- and sex-matched normouricemic control participants (n = 34), underwent a gray-scale and power Doppler ultrasound assessment of bilateral MTP1 joints by a single musculoskeletal radiologist. No participants had clinical evidence of joint inflammation at the time of scanning. The static images were later read by 2 musculoskeletal radiologists for the presence of the double contour sign, tophus, erosion, effusion, synovial hypertrophy, synovitis, and cartilage thickness.

RESULTS: Compared to normouricemic control participants, participants with gout and participants with asymptomatic hyperuricemia had more frequent double contour sign (odds ratio [OR] 3.91, P = 0.011 and OR 3.81, P = 0.009, respectively). Participants with gout also had more erosion (OR 10.13, P = 0.001) and synovitis (OR 9.00, P < 0.001) and had greater tophus and erosion diameters (P = 0.035 and P < 0.001, respectively). More severe erosion and synovitis grades and a less severe effusion grade were independently associated with gout compared with asymptomatic hyperuricemia (R2  = 0.65, P < 0.001).

CONCLUSION: Urate deposition, synovitis, and bone erosion are common at the MTP1 joint in people with gout, even in the absence of flare. Although individuals with asymptomatic hyperuricemia lack ultrasound features of inflammation or structural joint changes, they demonstrate a similar frequency of urate deposition.