Subcutaneous flexor tendon rupture in patients with rheumatoid arthritis

Objective: We examined the clinical features and functional outcomes of surgically repaired subcutaneous flexor tendon ruptures in patients with rheumatoid arthritis (RA). Methods: This retrospective study included 41 fingers of 24 RA patients who underwent surgical treatment for flexor tendon ruptures. Evaluations performed at the time of presentation following rupture were C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity score in 28 joints (DAS28)-ESR, as well as Larsen grading for carpal bone destruction. The ruptured tendon and postoperative active range of motion (ROM) of digits were also examined. Results: The mean CRP was 2.4 mg/dl, ESR was 52 mm/h, and the DAS28-ESR was 4.5. Carpal bone destruction according to Larsen grade IV–V was observed in 18/24 patients. Affected digits were most commonly the thumb (12) and the ring and little fingers (9 each). Tendon ruptures were most common in the carpal tunnel in zone IV. The mean postoperative finger ROM (flexion/extension) was 38°/2° for the interphalangeal (IP) joint of the thumb and 23°/−2° for the distal interphalangeal joint of the other four fingers. Conclusions: Patients with flexor tendon ruptures present with high disease activity and advanced bone destruction. It is important to reduce the risk of progressive bone destruction and subsequent tendon rupture via tight control of disease activity.