33rd Annual Scientific Meeting proceedings

Introduction
Stress-related bone injuries are common in racehorses with a significant proportion resulting without a single inciting traumatic event. Fractures of the third metacarpal and metatarsal condyles are the most common long bone fracture type in racehorses. Other third metatarsal/metacarpal bone fracture configurations occur but, proximal, articular fractures are uncommon.

This report outlines the diagnosis, repair and outcome of 3 articular, proximal third metatarsal bone and 1 articular, proximal third metacarpal fractures.

Case Description
Three Thoroughbred and 1 Standardbred racehorses presented to the authors hospitals with histories of acute onset severe lameness following fast exercise. An articular, proximal 3rd metatarsal bone fracture with a dorsomedial-plantarolateral orientation was diagnosed in 3 cases and an articular proximal 3rd metacarpal bone fracture with a dorsolateral-plantaromedial orientation was diagnosed in 1 case. Diagnosis was made using a combination of nuclear scintigraphy, radiography and computed tomography. Standing fracture fixation was performed in 3 cases, and under general anaesthesia in 1 case. In all cases internal fixation was achieved using 4.5mm cortical bone screws placed in lag fashion.

Results
All horses returned to work by 8 months post-surgery, and 3 have subsequently raced. One horse required screw removal due to lameness.

Discussion/Conclusions
This report highlights this fracture configuration and location as a site of work-related injury whilst demonstrating that successful fracture repair is achievable both standing and under general anaesthesia with favorable outcomes. Multiple oblique radiographic projections should be taken to identify the fracture line with scintigraphy and CT a useful adjunctive diagnostic tool.