Transection of the accessory ligament of the superficial digital flexor muscle for the treatment of superficial digital flexor tendinitis in standardbreds: 40 cases (1988-1992).

The research article discusses a procedure called transection of the accessory ligament of the superficial digital flexor muscle used to treat tendinitis in Standardbred racing horses. Despite a noticeable drop in winner’s payout post-surgery and a quarter of the horses experiencing re-occurrence of the tendinitis, the procedure allowed a high proportion of them to return to racing.

Study Overview

• The researchers retrospectively reviewed the medical records of 40 Standardbred racehorses that had undergone transection of the accessory ligament of the superficial digital flexor muscle (also known as ‘superior check desmotomy’) to treat superficial digital flexor tendinitis.
• The surgery was performed on both legs (bilaterally) in 32 horses, and on one leg (unilaterally) in 8 horses.

Concurrent Surgeries and Follow-ups

• In 8 cases where the tendinitis affected the distal metacarpal region and confinement by the annular ligament was suspected, an additional surgery (palmar annular desmotomy) was performed.
• Follow-up information was obtained either through phone conversations or from racing results.

Results and Success of the Procedure

• Out of the 32 horses that returned to training post-surgery, tendinitis returned in 8 horses, reflecting a re-occurrence rate of 25%.
• However, 35 of the 38 horses (over 90%) that had surgery were able to participate in at least one race after surgery.

Performance Post-Surgery

• The time between surgery and first race varied, with an average time of 237 days.
• Of the 38, 33 horses completed 5 or more races after surgery.
• Despite returning to racing, the median amount of money won per start after surgery ($418, range: $0 to $4,626) was significantly less than before the surgery ($1,155, range: $0 to $14,603).

Complications Post-Surgery

• Post-surgery, inflammation of the interosseous muscle (a ligament associated with joints formation) developed in 7 horses – 5 with bilateral and 2 with unilateral tendinitis surgery.
• All these horses had undergone bilateral superior check desmotomy.