Basal sesamoidean fractures in horses: 57 cases (1980-1991).

Medical records of 57 horses admitted between 1980 and 1991 because of basal sesamoidean fractures were evaluated. Radiographic measurements of fragment size and fracture characteristics were recorded to determine their relationship to outcome. A successful outcome was assessed on the basis of the ability to return to racing, ability to race more than one time, and ability to finish first, second, or third. Any change in racing class also was assessed. There was a significant (P < 0.001) overrepresentation of Thoroughbreds, compared with other breeds in the hospital population. Fractures of the forelimbs accounted for 50 of the 57 fractures, and the right front medial sesamoid was affected significantly (P < 0.0001) more frequently than other proximal sesamoids. Fifty-nine percent of the horses returned to race at least 1 time regardless of treatment, and 41% finished first, second, or third. Horses with smaller fragments (shorter dorsopalmar length) tended to do better than horses with larger fragments. Horses without comminuted fractures tended to do better than horses with comminuted fractures, and horses with fragments only mildly (< 3 mm) displaced had significantly (P < 0.05) better outcomes than did horses with severe displacement of fragments. Only 19% of the horses with moderate (> 3 mm) displacement of fragments raced more than once, whereas 63% of horses with mild displacement of fragments returned to race more than once. Seventy-three percent of the horses that had the fragment removed surgically returned to race, and 57% dropped in class. Only 48% of the horses that did not have the fragment removed returned to race, and 87% dropped in class.(ABSTRACT TRUNCATED AT 250 WORDS)