Assistant Professor of Large Animal Surgery University of Pennsylvania Kennett Square, Pennsylvania
Qualitative Assessment of Fracture Characteristics and Associated Subchondral Bone Pathology Using Computed Tomography in Thoroughbred Racehorses with Fractures of the Lateral Condyle of the Third Metacarpus/Metatarsus. Ortved K, Cianci J, Wulster K, Stefanovski D, Richardson D. University of Pennsylvania, New Bolton Center, Kennett Square, PA.
We aimed to investigate the effects of fracture characteristics and concurrent subchondral bone pathology identified with computed tomographic (CT) on racing performance of Thoroughbred racehorses with fractures of the lateral condyle of the third metacarpus/metatarsus (MC/MT3). The study population included Thoroughbred racehorses (n = 50) with a fracture of the lateral condyle of MC/MT3 that had a preoperative CT and internal fixation performed. Medical records were reviewed for age, sex, limb, and surgical treatment. CT scans were evaluated to determine fracture characteristics including length, displacement, and whether the fracture was incomplete or complete. The presence of subchondral bone injury (SBI), sesamoid bone fracture, articular comminution, and free joint fragmentation were noted. Racing data was obtained from an online database. Univariable and multivariable analyses determined associations between independent variables and outcomes. Thirty-three (66%) horses raced after surgery. Horses with sesamoid bone fractures (P = 0.021), comminution (P = 0.016) and free fragmentation (P = 0.015) were significantly less likely to race postoperatively. Concurrent SBI did not affect outcome. In the final multivariable model, sex (P = 0.015) and whether a fracture was incomplete or complete (P = 0.007) were the two most significant predictors of racing postoperatively with females and horses with complete fractures being less likely to race postoperatively. The prognosis for racing after a lateral condylar fracture is favorable but is decreased in horses with complete fractures and certain concurrent joint pathology. Horses presenting with lateral condylar fractures commonly have concurrent joint pathology. CT can aid in preoperative evaluation and prognostication of horses by enabling more complete fracture assessment.