Factors affecting extension lag after tendon reconstruction for finger extensor tendon rupture due to distal radioulnar lesion

Background: Although extensor tendon rupture associated with distal radioulnar joint disorder is often encountered, its treatment has not yet been established. We report the postoperative results for reconstruction of finger extensor tendon rupture due to distal radioulnar lesion and analyse the factors affecting postoperative extension lag. Methods: We examined 74 index, middle, ring, or little fingers with extensor tendon rupture of 34 hands. Primary diseases were rheumatoid arthritis in 24 hands and osteoarthritis in 10. Reconstruction methods included tendon graft in 45 fingers, extensor indicis proprius tendon transfer in 15, and end-to-side adjacent tendon suture in 14. At final postoperative follow-up ranging from 12 to 40 (mean: 18) months, we measured metacarpophalangeal (MCP) joint range of motion and extension lag and statistically evaluated the relationship between postoperative extension lag and several clinical factors. Results: We encountered no cases of re-rupture or worsening of finger flexion range after reconstruction. Mean postoperative active flexion of the MCP joint was 78.1 (range: 45-95) degrees. Mean postoperative extension lag was 10.3 (range: 0-50) degrees. We observed that postoperative extension lag was significantly larger in fingers associated with extensor tendon rupture in two or three additional fingers in the affected hand or in fingers of patients aged 80 years or over. The interval from rupture to reconstruction, reconstruction method, or arthritis type did not remarkably affect outcome. Conclusions: This study uncovered that surgical intervention for extensor tendon rupture should be performed before three fingers become affected. (C) 2015 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.