Sagittal plane slab fractures of the third carpal bone in 45 racing Thoroughbred horses

Abstract

Background: Sagittal plane slab fractures of the third carpal bone are a recognised injury in the racehorse. Currently no published data exist for the UK Thoroughbred racehorse population.

Objectives: To document return to racing following sagittal slab fracture of the third carpal bone in a UK-based racehorse population, and to compare conservative and surgical management.

Study design: Single centre retrospective study.

Methods: Computerised medical and racing records were searched over a 15-year period for Thoroughbred racehorses with a simple sagittal slab fracture of the third carpal bone. Horses with comminuted fractures and short incomplete linear lucencies were excluded. Time from intervention to next race was recorded. Success rates were compared by Fisher's Exact Test and Mann-Whitney U Test.

Results: Forty-seven horses, with 49 fractures met the inclusion criteria. Overall, 27 horses raced following injury (60%). Median time to first start was 251 days (115-600, IQR 109). Fifteen horses with 16 fractures were managed conservatively. Seven horses (47%) raced, 115-508 days following injury (median 240 days, IQR 306). Thirty horses underwent surgery; this involved placement of a single 3.5-mm lag screw under arthroscopic guidance. Twenty horses (67%) raced again 145-600 days following surgery (median 264 days, IQR 102). A higher proportion of horses managed surgically improved their Racing Post Rating (RPR) following injury (14/20), compared with those managed conservatively (1/7, P = .02).

Main limitations: The numbers of horses are small, particularly for those managed conservatively. Treatment was not randomly allocated, and as such several horses which underwent conservative management were subsequently retired for breeding.

Conclusions: This case series indicates that both arthroscopic repair and conservative management of sagittal slab fractures of the third carpal bone allows horses to successfully return to training and racing.

Keywords: fracture; horse; racehorse; sagittal; third carpal bone.