Lag screw fixation of dorsal cortical stress fractures of the third metacarpal bone in 116 racehorses.

This research focused on assessing the effectiveness of lag screw fixation surgery for treating dorsal cortical stress fractures in racehorses. The study found that this surgical procedure tend to be successful in allowing racehorses to return to racing activities at their pre-surgery performance levels.

Objective and Methods

• The primary purpose of this study was to investigate whether lag screw fixation for dorsal cortical stress fractures is an efficient surgical treatment that allows Thoroughbred racehorses to maintain their preoperative level of performance.
• The analysis was based on the examination of the medical records of 116 racehorses admitted to the Equine Medical Centre in California between 1986 and 2008.
• The data obtained from the medical records featured details such as the specifics of each horse’s condition, the affected limb(s), the fracture configuration, the length of the screw utilized for repairing the fracture, and whether other surgical procedures were performed at the same time.
• The researchers compared racing performance relative to these factors using statistical analysis methods, mainly Fisher’s exact test and nonparametric tests, with a level of significance set to P<0.05.

Results and Findings

• According to the results, it was revealed that of the total 92 Thoroughbred horses that took part in racing activities before and after surgery, the percentage did not change significantly (83%).
• The study found that 63% of these horses had five or more starts, indicating that most of them were able to maintain regular racing following surgery.
• The study found no strong statistical association between factors like the age, gender, the affected limb, fracture configuration or the presence of concurrent surgery, and the chances of a horse returning to racing after surgery or having 5 or more starts.
• The average earnings per start and the performance index for the 3 races following surgery were found to be lower compared to the 3 races prior to the operation. However, a noticeable percentage (29% and 45%) of horses either improved or did not change their earnings per start and performance index, respectively.

Conclusions

• The research concludes that lag screw fixation seems to be an effective surgical procedure in treating dorsal cortical stress fractures in racehorses.
• It demonstrates clear potential in restoring the ability of horses to participate in racing activities with significant success, maintaining a stable performance level, although the exact effect on racing performance varies among individual cases.