34th Annual Scientific Meeting proceedings

Objectives:

Proximal sesamoid bone fractures (PSBFs) are a leading cause of economic losses in racing Thoroughbreds. A recent analysis is absent from the literature.

 

Methods:

Thoroughbred racehorses undergoing surgical management of PSBFs (2010-2022) were included. Data retrieved included fracture type, limb, axiality, treatment, age, sex, surgical date, date of first post-surgical start, number of pre- and post-surgical starts and places (1-3). A performance index (PI) and PI per start (PI/S) were generated by assigning numerical values to each place. Chi-squared analysis assessed effect of categorical variables (sex, limb, fracture type, axiality, presence of suspensory ligament damage and whether horses raced pre-surgery) on racing outcome (racer/non-racer). Wilcoxon signed-rank assessed significance between pre and post-surgical PI and PI/S. Kruskal-Wallis and Mann-Whitney U tests assessed significance between categorical and numerical variables (age, number of days between surgery and racing, number of starts, PI and PI/S).

Results:

92/177 (52%) of all horses and 61/118 (52%) of horses that raced pre-surgery, raced post-surgery. Mid-body fractures and forelimb fractures were significantly less likely to race post-surgery compared with other fracture types (P<0.01) and hindlimb fractures (P<0.01) respectively. Mid-body fractures started significantly fewer races than apical (P<0.01) and abaxial fractures (P<0.01). Median pre-surgical PI/S was significantly greater compared to post-surgical PI/S (P<0.05); no association was observed for PI. The median number of post-surgical starts was 6.

Conclusions:

Horses undergoing surgical treatment for apical and abaxial fractures have a good prognosis for racing.   In contrast to previous reports axiality had no effect on outcome. Horses returning to racing have good longevity.