Results of screw fixation combined with cortical drilling for treatment of dorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses.

The research investigates the effectiveness of a surgical procedure involving screw fixation and cortical drilling for treating stress fractures in the third metacarpal bone in racehorses. The authors found a high success rate, evidenced by fracture healing and the ability of the horses to resume racing post-operation, with no significant impact on racing performance or earnings.

Methodology

• The study comprised 56 Thoroughbred racehorses diagnosed with dorsal cortical stress fractures of the third metacarpal bone (MCIII).
• Information was compiled from medical records and radiographs pertaining to the horses’ age, sex, limb affected, fracture assessment, and postoperative recommendations.
• Fracture healing was evaluated radiographically at the time of screw removal.
• The performance of the horses post-operation was determined using race records from The Jockey Club Information System in Lexington, Kentucky.

Results

• Stress fractures were noticed mainly in the left front limb of the male 3-year-olds, typically on the dorsolateral cortex of the middle third of MCIII.
• Most of the fractures (97%) followed a dorsodistal to palmaroproximal direction.
• The median period for screw removal was approximately 2 months.
• A staggering 98% of the single stress fractures of the left front limb were deemed healed based on evaluations at the time of screw removal.
• After the surgery, the median times to resume training and to race were approximately 2.75 months and 7.62 months, respectively.
• The earnings per start – before and after the surgical intervention – were not significantly different statistically.
• Of the total 63 fractures that were treated, two experienced a recurrence.
• There were no catastrophic failures, and no incisional infections were noticed.

Conclusion

• The high rate of healing and the ability of the horses to resume racing suggest that screw fixation combined with cortical drilling is an effective surgical remedy for dorsal cortical stress fractures of the MCIII in Thoroughbred racehorses.
• The lack of significant difference in race earnings pre- and post-operation indicates that this procedure does not adversely affect the performance of the racehorses.