Analysis of stress fractures associated with lameness in Thoroughbred flat racehorses training on different track surfaces undergoing nuclear scintigraphic examination.
Authors: MacKinnon M C, Bonder D, Boston R C, Ross M W
Journal: Equine veterinary journal
Summary
# Editorial Summary MacKinnon and colleagues conducted a retrospective analysis of nuclear scintigraphic examinations from two equine hospitals to determine whether training surface influences the prevalence of stress fractures in Thoroughbred flat racehorses. Examining 528 scans from horses training on either dirt or synthetic surfaces at one facility (before and after a documented surface change in 2006) and additional populations from a second facility, the researchers used blinded image review and statistical analysis to compare stress fracture detection rates across groups. Synthetic surface training was associated with a significantly higher proportion of overall stress fractures (31.7% versus 23.0% on dirt; P = 0.03), with particular increases in hindlimb/pelvic fractures and tibial stress fractures. Whilst the findings suggest surface-related differences in injury patterns, the authors acknowledge that training philosophy and other management variables likely play substantial roles, indicating that surface choice alone cannot be isolated as the sole determinant of stress fracture risk. These results warrant consideration during facility planning and training programme design, though practitioners should recognise this as observational evidence requiring prospective validation before drawing definitive conclusions about surface safety profiles.
Read the full abstract on PubMed
Practical Takeaways
- •Track surface choice (synthetic vs. dirt) may meaningfully impact stress fracture risk in flat racehorses; trainers and veterinarians should monitor hindlimb and tibial regions closely in horses training on synthetic surfaces
- •Surface type alone does not fully explain stress fracture occurrence—training methods, intensity, and management practices require equal consideration when assessing lameness risk
- •Clinical monitoring via scintigraphy may be warranted for horses transitioning to synthetic track training to detect early stress fractures
Key Findings
- •Horses training on synthetic surfaces had significantly higher proportion of stress fractures (31.7%) compared to dirt surface (23.0%, P=0.03)
- •Synthetic surface-trained horses showed greater proportion of hindlimb/pelvic stress fractures (P<0.04) and tibial stress fractures (P=0.03) than dirt-trained horses
- •Training philosophy and other factors beyond surface type appear to influence stress fracture occurrence