Apical fractures of the proximal sesamoid bones in 109 Standardbred horses

One-hundred and nine apical fractures of the proximal sesamoid bones were diagnosed in Standardbred racehorses at the Ohio State University Veterinary Hospital during a 5-year period ending December 1978. Lateral sesamoids of the hindlimbs accounted for 61 of the 109 fractures, which was a significantly (P less than 0.05) greater proportion than that for fractures in all other sesamoid bones. Two- and three-year-old horses accounted for 73 of the 109 apical sesamoid fractures. The remaining 36 apical sesamoid fractures were in horses 4 to 9 years old. The apical fragment was removed in 80 of the horses. Thirty-six (45%) of these had raced prior to surgery, and 40 (50%) of them raced after surgery. Surgical treatment did not significantly change the earnings, starts, or order of finish score of the horse, when average before-injury performance values were compared with average after-surgery performance values. Sixty-four percent of horses that raced before injury raced afer surgery. horses that raced before injury had significantly better (P less than 0.05) performance after surgery than those not raced prior to injury. Sixty percent of horses undergoing surgery within 30 days of injury returned to race performance, and these horses had significantly (P less than 0.05) better performance after surgery than those operated on more than 30 days after injury. Thirty-six percent of horses with suspensory desmitis raced after surgery, and their race performance was poor. Twenty-nine horses with apical fractures were treated nonsurgically. Twenty-one (69%) had raced before injury, and 10 (37%) raced after injury. The performance of the 10 was significantly poorer (P less than 0.05) when their preinjury performance was compared to their after-injury performance. There was bias in selecting patients for nonsurgical treatment.