Osteochondral fragments of the pastern joint at the origin of the collateral ligament of the distal sesamoid bone: performance after arthroscopic removal (2000-2015).

Abstract

OBJECTIVE To describe the presence of fragments in the dorsal proximal interphalangeal (PIP) joint and to report flat racing performance after surgical treatment. STUDY DESIGN Retrospective study. SAMPLE POPULATION Thirty-nine affected thoroughbred flat racehorses and 169 age- and sex-matched maternal siblings. METHODS Medical records from 2000 to 2015 were reviewed for thoroughbred horses that underwent arthroscopic removal of osteochondral fragments in the dorsal aspect of the PIP joint. The horses' 2-year-old year, 3-year-old year, and career athletic performances were compared with their matched siblings. RESULTS Thirty-nine thoroughbred horses were included, varying in age from 4 months to 4 years, with osteochondral fragments in 42 PIP joints. Hind limbs (92%) were more commonly affected than forelimbs (8%). Fragments were located within the origin of the collateral ligament of the distal sesamoid (navicular) bone. After surgery, the likelihood of starting a race did not differ between treated horses (27/39 [69%]) and maternal siblings (129/169 [76%], P = .15). Race earnings did not differ between treated horses and their siblings during their 2-year-old year (P = .66), 3-year-old year (P = .43), or career (P = .60). CONCLUSION Removing osteochondral fragments from the origin of the collateral ligament of the distal sesamoid bone did not impair the ability to race or earning potential for affected thoroughbred racehorses compared with their maternal siblings. CLINICAL SIGNIFICANCE Fragments from the dorsal aspect of the PIP joint in racehorses can be removed arthroscopically resulting in a good clinical outcome and future flat racing performance comparable to matched controls.