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

This research study evaluates the long-term effects and potential benefits of surgically cutting (desmotomy) the accessory ligament of the deep digital flexor tendon in adult horses, a procedure that could be a viable treatment for chronic tendon inflammation (desmitis).

Methodology

• The study focused on six adult Standardbred trotting horses.
• Biomechanical data from before and six months after desmotomy were collected and compared.
• Various parameters, including joint angles while walking and trotting, ground reaction forces, peak joint moments, and tendon forces, were assessed.

Results

• All horses were able to move comfortably at a trot within ten days after surgery.
• Side effects such as swelling, increased bending (flexion) of the carpal joint during the final stance phase, and accidentally tripping at the start of exercise were observed.
• The flexion angle in the carpal joints significantly increased at the end of the stance phase.
• However, peak moments around the distal interphalangeal joint, as well as the forces in the Deep Digital Flexor Tendon (DDFT) and the accessory ligament-DDFT, were decreased.
• The metacarpophalangeal joint angles, peak metacarpophalangeal joint moments and peak load on the suspensory ligament and the superficial digital flexor tendon remained unchanged.

Conclusions

• Six months after desmotomy, the strain on the accessory ligament-DDFT was reduced without causing an increase in joint angles or in tendon loads or joint moments that could have been risky for the horses.
• The changes in locomotion that remained six months after the AL-DDFT desmotomy could be acceptable for horses with chronic desmitis if conservative treatments failed to show efficacy.

This research suggests that desmotomy could potentially be an effective surgical procedure for treating chronically inflamed tendons in horses, though longer-term studies may be necessary to confirm the safety and benefits of this treatment approach.