Race Performance Following Arthroscopic Surgery for Femoropatellar and Tarsocrural Osteochondrosis in Juvenile Thoroughbreds.

OBJECTIVE: The objective of this study is to evaluate racing performance of Thoroughbred yearlings following arthroscopic surgery for osteochondrosis (OC) of the femoropatellar (FP) and tarsocrural (TC) joints. STUDY DESIGN: This is a retrospective study of Thoroughbreds < 2 years old undergoing arthroscopic surgery for OC in the FP or TC joint (2010-2022). For each case, two age- and sex-matched controls from the same stud farm were selected. Lesions were graded on preoperative radiographs and described. Racing outcomes (number of starts, wins, places, podiums, prize money at 2nd, 3rd, and ≥4-year-old seasons, and career duration) were compared between groups using parametric or nonparametric tests according to data distribution (Student's t-test/analysis of variance or Mann-Whitney U/Kruskal-Wallis tests). RESULTS: A total of 49 horses included: 27 in the FP group and 22 in the TC group. In the FP group, the lateral trochlear ridge was most often affected; 14 were bilateral, two had OC lesions in another joint. In the TC group, the distal intermediate ridge of the tibia was mainly affected; five were bilateral and one had OC lesion in another joint. No significant differences were found between cases and controls in number of starts, wins, places, podiums, and prize money earned at 2nd, 3rd, and ≥4-year-old racing careers or career duration for either group (p > 0.05). In both groups, no significant performance differences were found between unilateral and bilateral cases (p > 0.05). CONCLUSION: Racing performance after FP or TC OC surgery was comparable to that of unaffected controls. Bilateral cases performed as successfully as unilateral.