Hand flexor tenosynovitis in rheumatoid arthritis. Prevalence, distribution, and associated rheumatic features.

Tenosynovitis of one or more flexor tendons of the hand (mean 3.1 tendons per patient) was noted in 55% of 100 patients with rheumatoid arthritis (RA) examined periodically during a mean period of 5 years. The third flexor tendon was involved most frequently (71% of patients), followed by the second (62%), fourth (53%), fifth (27%), and first (13%). Patients with flexor tendonitis (FT) had a significantly higher prevalence of rheumatoid nodules (56% vs 33%), carpal tunnel syndrome (47% vs 13%), wrist extensor tenosynovitis (47% vs 9%), and elbow epicondylitis (22% vs 7%) than patients without FT. Dupuytren's contracture, DeQuervain's tenovaginitis, flexor carpi radialis and ulnaris tendonitis, and Achilles tendonitis were found exclusively in patients with FT. A control group of 50 non-RA patients with FT had statistically fewer diseased tendons per patient (mean 1.5) and a different digital distribution, the thumb being affected more frequently (P less than 0.05) than in RA patients.