Musculoskeletal ultrasound findings in people with asymptomatic hyperuricemia: baseline analysis from the Transitions in Gout Research (TIGER) study using the OMERACT gout ultrasound semiquantitative scoring system.

OBJECTIVES

The objective of this study was to describe the musculoskeletal ultrasound features of asymptomatic hyperuricaemia using the Outcome Measures in Rheumatology (OMERACT) gout semiquantitative scoring system and examine relationships between ultrasound lesions.

METHODS

Participants with serum urate ≥0.48 mmol/L, no previous gout flares, and no subcutaneous tophi (n = 269) underwent a standardised ultrasound examination of bilateral patellar tendons, knee, first and second metatarsophalangeal joints (MTPs), and Achilles tendon. Double contour, tophus, and aggregates were scored according to the OMERACT gout ultrasound semiquantitative scoring system (0-3, with score >1 indicating a definite finding), together with erosion, synovial hypertrophy, and power Doppler activity in the scanned joints. In addition to elementary lesion sum scores, the sum of the semiquantitative double contour scores and tophus scores was calculated for each participant (semiquantitative double contour-tophus [SQDT] sum score, maximum 60).

RESULTS

There were 38.7% of participants with at least 1 definite double contour and/or tophus on ultrasound. The median (IQR) SQDT sum score was 2 (0-4). Double contour scores contributed most to the SQDT sum score, followed by first MTP tophus scores. Double contour was associated with synovial hypertrophy at the first and second MTP, and tophus was associated with erosion, synovial hypertrophy, and power Doppler activity at the first MTP.

CONCLUSIONS

Definite ultrasound features of gout can be identified in more than one-third of people with asymptomatic hyperuricemia. However, the amount of monosodium urate crystal deposition on ultrasound, assessed using the OMERACT gout ultrasound scoring system, is low. In asymptomatic hyperuricemia without clinical evidence of gout, ultrasound features of gout are associated with subclinical joint damage and inflammation.