Flexural deformity of the distal interphalangeal joint in the horse: results of 53 desmotomies in 40 foals

ABSTRACT Desmotomy of the accessory ligament of the deep digital flexor tendon is a frequently performed surgical technique in foals to treat flexural limb deformity of the distal interphalangeal joint. In this retrospective study with 40 foals varying in age from 15 days to 18 months, 53 desmotomies were performed. The follow-up period varied from 2 to 12 years. In 85% (34/40) of the foals a desmotomy had a successful outcome. Both type 1 and 2 flexural deformities could be corrected. Preoperative changes in hoof conformation, which appeared especially in older foals (mean age 10.2 months), could also be corrected. The prognosis in foals with a bilateral flexural deformity was less favorable. Changes of the distal phalanx on radiographic examination seemed to play a role in preoperative lameness but did not have any effect on the post-operative outcome of the desmotomy. Although changes in hoof conformation in older foals can successfully be corrected through desmotomy, surgical correction in young foals is preferred, since changes in hoof conformation in these patients are rather rare. In the opinion of the authors, desmotomy should not be postponed if conservative treatment does not improve a type 1 deformity within a couple of weeks, or in case of severe deformity (type 2).