The Correlation between Musculoskeletal Ultrasonographic Findings and Laboratory Data of Gouty Arthritis

Objective: Gout is a common inflammatory arthritis caused by the deposition of monosodium urate (MSU) monohydrate crystals in joints. We investigated how musculoskeletal ultrasonography (MSKUS) contributed to detect gouty arthritis and monitor disease activity after treatment. Methods: This is a retrospective review of clinical manifestation and MSKUS changes in 171 consecutive patients with gouty arthritis. All patients had their gout confirmed by the MSU crystal from the synovial fluid aspiration. The data were analyzed by Mann-Whitney U test or Phi coefficient test as appropriate, and p values ＜ 0.05 were considered significant. Results: The joint effusion, synovial proliferation, tenosynovitis, Baker's cyst, tophi, and the double contour (DC) sign were respectively detected in 93.0%, 50.3%, 29.8%, 18.7%, 14.6%, and 28.7% of patients. The patients with higher white cell count (WCC) in synovial fluid had lower risk of tenosynovitis (p = 0.04), Baker's cyst (p = 0.04), and DC sign (p ＜ 0.01). Patients with intraarticular tophi deposition had lower serum uric acid level (p = 0.013). Patients exhibiting synovial proliferation had higher prevalence of joint effusion (p ＜ 0.01) and Baker's cyst (p ＜ 0.01), but lower prevalence of tenosynovitis (p ＜ 0.01) and tophi (p = 0.016). Conclusion: MSKUS is a valuable tool for detecting structural changes of joint or extra-articular space in patients of gouty arthritis. Patients with chronic gouty arthritis characterised by Baker's cyst, DC sign and tophi usually have received long-term treatment and have less inflammation in synovium. Integrating clinical manifestations, MSKUS features and laboratory examinations helps guide physicians evaluate inflammation in joints and prescribe adequate treatment for gouty arthritis.