Tendonitis of the branches of insertion of the superficial digital flexor tendon in horses.

The study investigates a type of injury known as tendonitis, affecting the branches of the superficial digital flexor (SDF) tendon in Thoroughbred horses, focusing on clinical findings, ultrasonographic features, and ultimate outcomes.

Methods

• The study is retrospective, drawing insights from a total of 14 cases of Thoroughbred horses that suffered from tendonitis.
• Each horse was examined for lameness, location and amount of swelling, and the presence of other musculoskeletal abnormalities.
• Ultrasonographic examination was employed to assess the condition of the flexor tendons.
• Based on the findings, suggestions were made regarding case management.
• The outcome was evaluated by re-examining some horses, interacting directly with the horse owner or trainer, and scrutinizing race records.

Findings

• There was higher prevalence of the lateral SDF branch injuries among the horses, observed in 10 out of 14 horses.
• Three horses presented with injuries on the medial branch while one was affected on both branches.
• Two horses exhibited simultaneous injuries to the SDF tendon in the metacarpal region of the contralateral limb.
• The ultrasonographic examination detected swelling in the affected SDF branch, accumulation of fluid around the tendon, disruption of alignment in tendon fibers and variable degree of echogenicity disruption.
• During the healing process, the return of normal echogenicity was noted. However, normal fibre alignment did not fully restore, and adhesions appeared between the injured SDF branch and nearby structures.

Outcomes

• Seven out of ten horses that returned to their former use managed to compete without additional tendon injuries.
• Recurrence of injury was observed in one case, and another two horses developed tendonitis in the metacarpal region.
• One horse retired from racing and began competing in dressage without injury recurrence.
• Two horses were used for breeding without resuming training, and one horse was sold and hence lost to follow-up. However, this horse didn’t participate in any races.

Conclusion

• Overall, the study concluded that the prognosis for Thoroughbred horses returning to their previous activity levels, after injury to the branches of insertion of the SDF tendon, is generally good.