Ultrasonographic-based predictive factors influencing successful return to racing after superficial digital flexor tendon injuries in flat racehorses: A retrospective cohort study in 469 Thoroughbred racehorses in Hong Kong.
Authors: Alzola R, Easter C, Riggs C M, Gardner D S, Freeman S L
Journal: Equine veterinary journal
Summary
# Editorial Summary: Predicting Return to Racing After SDFT Injury Superficial digital flexor tendon injuries represent a significant welfare and economic concern in racing Thoroughbreds, yet ultrasonographic prognostic indicators have remained poorly defined until now. Alzola and colleagues conducted a retrospective analysis of 469 horses with forelimb SDFT injuries from the Hong Kong Jockey Club (2003–2014), applying a validated ultrasonographic scoring system to identify features at initial presentation that predicted successful return to racing (defined as completing ≥5 subsequent races). The study revealed two distinct prognostic pathways: in tendonitis cases with core lesions, cross-sectional area of the maximal injury zone proved most predictive, with lesions occupying <50% of the tendon cross-section offering 29–35% success probability compared to just 11–16% when ≥50% was affected; conversely, in core lesion-absent tendonitis, longitudinal fibre pattern disruption was the key predictor, with <75% involvement yielding 49–99% success probability versus 14% when ≥75% was compromised. These quantifiable ultrasonographic benchmarks enable practitioners to provide evidence-based prognostic counselling early in the clinical course, though findings remain specific to Thoroughbred racing on the studied tracks and may not directly translate to other breeds or disciplines.
Read the full abstract on PubMed
Practical Takeaways
- •Use initial ultrasound measurements of lesion size and fibre pattern disruption to provide evidence-based prognostic counseling to owners about realistic return-to-racing expectations
- •Horses with core lesions involving ≥50% cross-sectional area have significantly guarded prognosis (<16% return rate); those with non-core lesions showing ≥75% fibre disruption also have poor prognosis (~14% return rate)
- •Standardized ultrasonographic scoring at initial presentation enables objective prognostic assessment and supports early decision-making on treatment intensity and athletic retirement
Key Findings
- •In SDFT tendonitis with core lesions, cross-sectional area <50% at the maximal injury zone yielded 29-35% probability of successful return to racing versus 11-16% if ≥50%
- •In SDFT tendonitis without core lesions, affected longitudinal fibre pattern <75% predicted 49-99% success rate versus 14% if ≥75%
- •Cross-sectional area and longitudinal fibre pattern at initial ultrasonographic presentation are the strongest predictors of racing success in respective injury types
- •This is the first study to identify specific ultrasonographic features at initial presentation that predict successful return to racing in Thoroughbreds with forelimb SDFT injuries