Long-term consequences of experimental desmotomy of the accessory ligament of the deep digital flexor tendon in adult horses

Abstract

Abstract Objective To evaluate clinical and biomechanical consequences of desmotomy of the accessory ligament (AL) of the deep digital flexor tendon (DDFT) of equine forelimbs and determine whether this procedure is a viable treatment for chronic desmitis of the AL-DDFT. Animals 6 adult Standardbred trotters. Procedure Biomechanical recordings obtained before and 6 months after desmotomy were compared. Walk and trot joint angles, ground reaction forces, peak joint moments, and tendon forces were assessed. Results Within 10 days after surgery, all horses were sound at a trot. Swelling, increased carpal flexion in the terminal stance phase, and incidental stumbling at the beginning of exercise were observed. Flexion angle in the carpal joints was significantly increased at the end of the stance phase. Peak moments around the distal interphalangeal joint and forces in the DDFT and AL-DDFT were decreased. Metacarpophalangeal joint angles, peak metacarpophalangeal joint moments, and peak loading of the suspensory ligament and the superficial digital flexor tendon were unchanged. Conclusion 6 months after desmotomy, AL-DDFT strain was reduced without causing changes in joint angles or increasing tendon loads or joint moments that could be considered hazardous for the horses. Clinical Relevance Changes in locomotion that remained 6 months after AL-DDFT desmotomy would be acceptable for horses with chronic desmitis if conservative treatment failed. (Am J Vet Res 1998;59:347–351)