Treatment of Stage 2 or greater flexural deformities in a foal, yearling or adult horse often relies on surgical management in addition to conservative therapy. While the limb might return to normal visual orientation following desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) to correct a sole-dorsal hoof wall angle >900, a research endeavor sought to identify how this surgery might affect athletic performance in later years. Success with this surgery has previously been reported as 78%-97%. The study compared long-term athletic performance in sport horses undergoing desmotomy of the AL-DDFT to matched controls [Wismann, E.S.; Jacobsen, S.; Thofner, M.; et al. Long-term athletic performance in sport horses after desmotomy of the accessory ligament of the deep digital flexor tendon. Equine Veterinary Journal May 2021; DOI: 10.1111/evj.13472].
The Danish retrospective study evaluated horses from 2004–2015 with a previous diagnosis of flexural deformity of the coffin joint. These horses were of breeds likely to enter into the Olympic disciplines of dressage, show jumping or eventing, and each animal was registered in the Danish horse registration database. Horses were not included in the study if they had received other orthopedic surgical procedures.
Parameters assessed included:
- Did horses entered competition
- Age of entry into competition
- The number of registered competitions in which the horse participated
- Total time in competition
There were 74 horses in the study that fulfilled the inclusion criteria. There were 194 matched controls that did not receive desmotomy.
The results established that 28% (21/74) of desmotomy horses entered competition compared to 38% (74/194) of non-surgical horses. Surgery was performed between 33-780 days of age. It made no difference whether surgery was done on one or both front limbs, and age at surgery had no influence on the odds of entering competition. In addition, surgery did not delay a horse’s athletic career.
Those entering competition were as follows:
- Dressage was performed by 67% with desmotomy and 78% without.
- Show jumping was performed by 19% with desmotomy and 12% without.
- Eventing was performed by none with desmotomy and 1% without.
- Multiple disciplines were pursued by 14% with desmotomy and 9% without.
Age of entry into competition did not differ between desmotomy or non-surgical sport horses. However, career longevity was reduced in horses with desmotomy in comparison with those that had no surgery, and non-surgical competitors had more durability.
The study authors concluded: “There is a significant association between desmotomy of the AL-DDFT and/or the underlying reason for performing the surgery and reduced career longevity in sport horses.”
The researchers further stressed: “Recommendations regarding individual horses should not be based solely on the results of the current study but also on evaluation of any concurrent developmental problems that might influence athletic performance.”