Regenerative biologics modulating inflammation and promoting tenogenesis in equine superficial digital flexor tendonitis: from molecular pathways to clinical translation.

Abstract

Superficial digital flexor (SDF) tendonitis is a major cause of lameness and early retirement in equine athletes. Research has shifted the understanding of tendonitis from being only a degenerative condition to recognizing inflammation as a central and dynamic factor in both its development and repair. While regenerative therapies such as platelet-rich plasma and mesenchymal stem cells have demonstrated promising benefits, their clinical efficacy remains inconsistent, and no single gold-standard protocol has yet emerged. This review highlights the inflammatory concept of equine tendonitis, with a focus on cellular and molecular mechanisms behind tenogenesis. In addition, we explore the emerging evidence supporting regenerative biologic interventions in modulating inflammation and promoting tenogenesis. With ongoing advances in the understanding of tendon pathobiology, this review highlights inflammation as a central determinant of tendon healing outcomes and outlines promising therapeutic avenues, such as autologous conditioned serum, injectable platelet-rich fibrin, and mesenchymal stem cells-derived exosomes, for SDF tendonitis in equine.