The prevalence of tenosynovitis of the interosseous tendons of the hand in patients with rheumatoid arthritis.

Objective: The aim of this study was to establish the prevalence of tenosynovitis affecting the interosseous tendons of the hand in a rheumatoid arthritis (RA) population and to assess for association with metacarpophalangeal (MCP) joint synovitis, flexor tendon tenosynovitis or ulnar drift.

Methods: Forty-four patients with RA underwent hand MRI along with 20 normal controls. Coronal 3D T1 VIBE sequences pre- and post-contrast were performed and reconstructed. The presence of interosseous tendon tenosynovitis was recorded alongside MCP joint synovitis, flexor tendon tenosynovitis and ulnar drift.

Results: Twenty-one (47.7%) patients with RA showed interosseous tendon tenosynovitis. Fifty-two (14.8%) interosseous tendons showed tenosynovitis amongst the RA patients. Interosseous tendon tenosynovitis was more commonly seen in association with adjacent MCP joint synovitis (p < 0.001), but nine MCP joints (5.1%) showed adjacent interosseous tenosynovitis in the absence of joint synovitis. Interosseous tendon tenosynovitis was more frequently seen in fingers which also showed flexor tendon tenosynovitis (p < 0.001) and in patients with ulnar drift of the fingers (p = 0.01).

Conclusions: Tenosynovitis of the hand interosseous tendons was found in 47.7% of patients with RA. In the majority of cases this was adjacent to MCP joint synovitis; however, interosseous tendon tenosynovitis was also seen in isolation. Conclusions: • Tenosynovitis of the interosseous tendons of the hand occurs in rheumatoid arthritis. • Interosseous tendon tenosynovitis has a prevalence of 47.7% in patients with RA. • Interosseous tendon tenosynovitis is related to MCP joint synovitis in the adjacent joints.