TIBIAL STRESS-FRACTURES IN RACING STANDARDBREDS - 13 CASES (1989-1993)

Objective-To determine clinical signs, radiographic and scintigraphic findings, and performance outcome of racing Standardbreds with tibial stress fractures. Design-Retrospective case series. Animals-13 racing Standardbreds with tibial stress fractures. Procedure-Information conc erning clinical signs, diagnostic evaluation, and recommendations was obtained by review of the medical records. Performance information bef ore and after diagnosis of the fracture was collected from racing reco rds, and follow-up information was obtained from the owners or trainer s by use of a telephone questionnaire. Results-Horses with tibial stre ss fractures were moderately lame, and diagnosis was made by nuclear s cintigraphy and radiography. Fractures were more likely to occur in 2- year-old horses than In older horses. The fracture location was unique for Standardbreds; 11 of 13 developed stress fractures in the mid-dia physis of the tibia, whereas fractures in Thoroughbreds are usually in the proximal caudal or caudolateral cortex. Fractures occurred in you ng horses that had raced or were in advanced race training. All horses were treated with rest alone, and 10 of 13 horses raced after injury. The horses that raced after injury were able to return to a level of performance that was equal to or better than the level raced before in jury, 8 of 10 horses established a lifetime-best winning time after in jury. Clinical Implications-Tibial stress fractures are a cause of lam eness in young racing Standardbreds. Diagnosis is aided by nuclear sci ntigraphy. The prognosis for return to previous level of performance a fter a tibial stress fracture is good.