Autologous conditioned serum IRAP efficacy for tendon and ligament injuries in horses: An observational study
Authors: S. Tommasa, Sarah Raspe, G. Farì, Annarita Imperante, Walter Brehm
Journal: Open Veterinary Journal
Summary
# Editorial Summary: Autologous Conditioned Serum for Equine Tendon and Ligament Injuries Tendon and ligament injuries remain a significant source of morbidity in equine athletes, with conventional conservative management often failing to restore full functional integrity and increasing reinjury risk. Tommasa and colleagues conducted a retrospective case-control analysis of 100 horses treated for superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) injuries between 2017 and 2022, comparing intralesional autologous conditioned serum (ACS/IRAP) injections administered at weekly intervals (n=48) against conservative management with NSAIDs and rehabilitation alone (n=52), with lameness scoring and ultrasonographic assessment at 4, 8, and 12 weeks. Whilst ACS demonstrated modest benefit by 12 weeks (60.7% improvement versus 55% in controls), the advantage was variable by tissue type: SDFT and SL injuries showed superior outcomes with ACS (58.3% and 51.2% versus 48% and 36% respectively), but DDFT injuries responded better to conservative treatment alone (60.9% versus 46.2%), and approximately 8.5–17.7% of ACS-treated horses experienced transient lameness exacerbation. These findings suggest ACS may offer modest additive value for select soft tissue injuries, particularly suspensory ligament pathology, though the inconsistent response across lesion types and the occurrence of treatment-related lameness worsening indicate that current protocols require refinement and that robust randomised controlled trials remain essential before widespread clinical adoption can be justified.
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Practical Takeaways
- •IRAP injections show modest clinical benefit over conservative treatment for SDFT and SL injuries, but conservative management appears sufficient for DDFT injuries
- •Be prepared to counsel owners that approximately 10–18% of IRAP-treated horses may experience temporary lameness worsening post-injection, which typically resolves
- •Recovery timelines are comparable between IRAP and conservative therapy; benefits emerge gradually and require consistent rehabilitation protocols regardless of treatment choice
Key Findings
- •At 12 weeks, 60.7% of IRAP-treated horses and 55% of conservatively treated horses showed lameness improvement
- •IRAP treatment was superior for SDFT (58.3% vs 48%) and SL (51.2% vs 36%) injuries, but inferior for DDFT injuries (46.2% vs 60.9%)
- •Transient worsening of lameness occurred in 8.5–17.7% of horses receiving ACS injections
- •Improvement rates at 8 weeks were 47% (IRAP) versus 42.2% (NO-IRAP), with minimal difference at 4 weeks (51.5% vs 55.6%)