Treatment of racehorse superficial digital flexor tendonitis: A comparison of stem cell treatments to controlled exercise rehabilitation in 213 cases.
Authors: Salz Rachel O, Elliott Christopher R B, Zuffa Tomas, Bennet Euan D, Ahern Benjamin J
Journal: Equine veterinary journal
Summary
# Editorial Summary Superficial digital flexor tendon injuries represent one of the most economically significant conditions affecting Thoroughbred racehorses, yet optimal treatment protocols remain contested amongst veterinary practitioners. This retrospective cohort analysis examined 213 flat-racing Thoroughbreds with SDFT lesions—66 receiving autologous bone marrow-derived mesenchymal stem cells (BM-MSCs), 17 receiving allogenic adipose-derived stem cells (A-MSCs), and 130 managed with controlled exercise rehabilitation alone—all following a standardised 12-month rehabilitation programme, with a minimum two-year follow-up post-return to racing. Horses treated with intralesional BM-MSCs demonstrated substantially improved racing outcomes, with 3.19 times greater odds of returning to racing and 2.64 times greater odds of completing five or more races post-injury compared to rehabilitation-only controls; conversely, A-MSC treatment showed no significant benefit over exercise alone, whilst advancing age and longer initial lesion length negatively predicted return to racing. The findings suggest that autologous stem cell therapy, when combined with structured rehabilitation, may offer meaningful advantages for performance horses with SDFT injuries, though the retrospective design limits certainty regarding rehabilitation compliance across groups, and the limited A-MSC cohort warrants cautious interpretation of those results. Practitioners should consider these outcomes within their clinical context, recognising that individual horse factors—particularly age and lesion severity—significantly influence prognosis independent of treatment modality.
Read the full abstract on PubMed
Practical Takeaways
- •BM-MSC treatment combined with controlled exercise rehabilitation significantly improves racing comeback rates for SDFT injuries in flat racehorses compared to rehabilitation alone
- •Adipose-derived MSCs did not show benefit in this study population, suggesting cell source matters for SDFT treatment outcomes
- •Lesion size and horse age are important prognostic factors; consider these when counselling owners on treatment options and expected outcomes
Key Findings
- •Intralesional BM-MSC treatment increased odds of returning to racing 3.19-fold (95% CI 1.55–6.81) compared to CERP alone
- •BM-MSC treatment increased odds of completing 5+ races post-injury 2.64-fold (95% CI 1.32–5.33) versus CERP alone
- •Intralesional A-MSC treatment showed no significant association with return to racing or 5+ races compared to CERP alone
- •Older age and increasing lesion length reduced likelihood of return to racing; male sex and higher pre-injury starts increased likelihood