US findings of metacarpophalangeal joints in children with idiopathic juvenile arthritis

Abstract

Background: Juvenile idiopathic arthritis (JIA) is the most common cause of chronic arthritis in children, with frequent involvement of the metacarpophalangeal joints (MCPJ).

Objective: To compare US findings with those of radiography and clinical examination.

Materials and methods: All MCPJs in 20 children with JIA (17 females, median age 9.7 years, range 3.6 to 16.8 years) were evaluated clinically and imaged with gray-scale and color Doppler US, and 90 MCPJs were also imaged radiographically. Each MCPJ was graded on physical examination from 0 (normal) to 4 (severe) by the patient's rheumatologist.

Results: US demonstrated abnormalities in 64 of 200 MCPJs (32.0%), including pannus vascularity and/or tenosynovitis in 55 joints (27.5%) (pannus vascularity in 43, tenosynovitis in 40) and bone destruction in 25 joints (12.5%). Overall, US abnormalities and physical examination scores were significantly associated (P < 0.001). However, interobserver agreement between US and clinical evaluation was poor (kappa 0.1) and between US and radiography was only fair (kappa 0.4).

Conclusion: US of the MCPJ in children with JIA can demonstrate cartilage thinning, bone erosions, and pannus vascularity. Abnormal US findings are significantly correlated with severity of disease as evaluated clinically.