A stress fracture is a stress fracture, regardless of its location, right? Well, not necessarily; in some cases, a fracture’s location in a bone could have implications for whether the horse will return to his previous level of work or whether his career will be cut short. A research team recently examined whether the location of a stress fracture within the humerus impacted racing prognosis. Nicole Fawns, DVM, a fellow in the Comparative Orthopaedics Research Laboratory at the University of Pennsylvania School of Veterinary Medicine, presented the results at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas.

“Stress fractures are a major cause of lameness and result in significant economic loss within the Thoroughbred racing industry,” Fawns explained. “The objectives of this study were to characterize stress fractures in the humerus and to describe post-injury racing performance.”

Fawns and colleagues completed the retrospective study at Rood & Riddle Equine Hospital, in Lexington, Ky., using medical records from 88 Thoroughbred racehorses referred to the clinic from 1990 to 2010. Each of these horses had been diagnosed with a stress fracture of the humerus via radiography or nuclear scintigraphy.

“The influence of fracture location on racing performance was made by evaluating total earnings, total starts, average earnings, highest class raced, and length of time from injury to next race,” Fawns