Reconstruction and repair of atraumatic extensor tendon ruptures in rheumatoid wrists: Less extension lag after direct repair than interposition tendon grafting

The purpose of this study was to investigate the outcomes of extensor tendon repair involving the original stump in atraumatic extensor tendon rupture of rheumatoid wrists. For this study, 16 cases were reviewed involving 14 patients with rheumatoid arthritis. A total of 52 ruptured tendons impacted 36 fingers; 51 tendons were repaired in 35 fingers. The ruptured tendon stumps were repaired either directly by end-to-end suture or by free interposition tendon graft. The 8- to 10-strand core suture method was used for direct repair with a looped 4-0 nylon suture. In all patients, the extensor retinaculum was released and repaired under the tendons. Postoperatively, a volar splint with the wrist and fingers extended was applied for 3 to 4 weeks, followed by a removable splint and gentle active flexion until 6 weeks. The mean follow-up period was 32 months. All fingers recovered active metacarpophalangeal (MCP) joint extension, including independent and active extension of the little finger. Overall, the mean extension lag at the MCP joint was 1.7°. The mean fingertip-to-palm distance with the MCP joint flexed was 0.24 mm. The mean extension lag at the MCP joint was significantly greater after interposition tendon grafting (3.2°) than after direct repair (0°). There was no significant difference in the mean fingertip-to-palm distance between direct repair (0.38 mm) and interposition tendon grafting (0.13 mm). No re-rupture or additional extensor tendon rupture was observed. Repair of the original extensor tendon stump yields satisfactory outcomes and appears to be a viable alternative to tendon transfers in patients with rheumatoid wrists with atraumatic extensor tendon ruptures. Direct repair reduces postoperative extension lag without a significant difference in flexion deficit when compared with interposition tendon grafting.