Results of screw fixation combined with cortical drilling for treatment ofdorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses

The purpose of this study was to evaluate screw fixation with cortical dril ling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs, Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentuc ky. Fifty-six Thoroughbred racehorses were treated surgically for stress fr acture of MCIII with screw fixation and cortical drilling. Stress fractures occurred primarily in the left front limb of the male 3-year-olds, in the dorsolateral cortex of the middle third of MCIII, Ninety-seven percent of t he fractures travelled in a dorsodistal to palmaroproximal direction, Media n period to screw removal was 2.0 months. Evaluation at time of screw remov al revealed 98% of single stress fractures of the left front limb were heal ed radiographically, Median period to resume training was 2.75 months (sing le stress fractures); median period to race was 7.62 months, There was no s tatistically significant difference in earnings/start before and after surg ical intervention. Of the 63 fractures treated, two recurred. There were no catastrophic failures, and no incisional infections.