Career outcome of Thoroughbred racehorses with metacarpo/metatarsophalangeal joint dorsal chip fracture managed nonsurgically and surgically: A retrospective cohort study.

This research article discusses the career outcomes of Thoroughbred racehorses, either undergoing non-surgical or surgical management for treating dorsal osteochondral chip fractures, as compared with horses devoid of such fracture. The results indicate that the non-surgical approach, despite being less conventional, doesn’t show any significant negative impact on the horses’ racing performance relative to the exposed cohort in the study.

Study Objective and Methodology

• The main goal of this study was to evaluate the racing career outcomes of Thoroughbred racehorses diagnosed with dorsal osteochondral chip fractures and managed either non-surgically or surgically. The outcomes were compared with a group of horses that didn’t have such fractures (unexposed).
• The study was conducted retrospectively by analyzing records between 2006 and 2014.
• Radiographs of Thoroughbred racehorses were examined to identify metacarpo/metatarsophalangeal (MCP/MTP) dorsal osteochondral chip fractures.
• Unexposed horses were randomly selected from training records under the same practice facilities. This was done to maintain the control for variables beyond the treatment approach, ensuring the study’s accuracy.
• Different statistical techniques were employed to analyze the racing outcomes, including survival analysis, logistic, linear, and negative binomial regression.

Results

• A total of 98 horses were diagnosed with MCP/MTP dorsal osteochondral chip fractures. Of these, 70 were managed non-surgically, and 28 were treated surgically. These horses were compared with 648 unexposed horses.
• The study found no substantial difference in factors such as career starts and likelihood of winning, placing or earning money, among the non-surgically managed, surgically managed and unexposed horses.
• However, horses treated surgically had a significantly higher rate of wins per start than the non-surgically managed horses and the unexposed horses.
• The surgically treated horses also demonstrated 4.1 times the total career earnings of the unexposed horses.

Conclusions and Limitations

• The research concluded that non-surgical management for these fractures could be a valid choice, as it did not affect the racing career performance compared to a large unexposed cohort in this study.
• The study had a few constraints, including a non-randomised, non-blinded approach to identify the management technique. It also had a small sample size for the surgically managed horses, which imparts potential bias.