Arthroscopic removal of fracture fragments involving a portion of the baseof the proximal sesamoid bone in horses: 26 cases (1984-1997)

Objective-To determine the outcome of horses with basal fractures of the pr oximal sesamoid bone from which a fracture fragment involving a portion of the base of the bone was removed arthroscopically and to determine whether fragment size was associated with outcome. Design-Retrospective study. Animals-26 horses. Procedure-Dorsopalmar and axial-abaxial lengths of the fracture fragment we re measured on the dorsopalmar and mediolateral radiographic views, respect ively, and percentage of the base of the sesamoid bone involved was estimat ed. Fractures were classified as grade 1 (less than or equal to 25% of the base involved) or grade 2 (> 25% but < 100% of the base involved). Outcome was classified as successful if the horse started at least 2 races or unsuc cessful if the horse started only 1 race or failed to return to racing. Results-There were 24 racehorses and 2 nonrace-horses. Twelve (50%) of the racehorses returned to racing and started at least 2 races. Eight of 14 hor ses with grade-1 fractures and 4 of 10 horses with grade-2 fractures had a successful outcome. Ten of 16 horses without associated articular disease h ad successful outcomes, compared with 2 of 8 horses with associated articul ar disease. However, fragment size and presence of associated articular dis ease were not significantly associated with outcome. Conclusions and Clinical Relevance-Horses with basal fractures of the proxi mal sesamoid bone from which a fracture fragment involving a portion of the base of the bone is removed arthroscopically have a fair prognosis for ret urn to racing.