Systematic review and meta-analysis of adult multipotent stromal/stem cell treatment for equine tendinopathy and desmopathy

Introduction: Over the last few decades, cell and cell-based therapies emerged as treatment options for equine tendinopathy and desmopathy. The objective of this study was to critically evaluate outcomes following treatment of equine tendinopathy or desmopathy with adult multipotent stromal/stem cells (MSCs). Methods: The PubMed and Web of Science databases were searched for "equine/horse," "tendon/tendinopathy/tendonitis/ligament/ligamentopathy/desmopathy/desmitis," "stem/stromal/mesenchymal/multipotent," and "cell" from January 2001 to June 2025. Studies were identified according to PRISMA guidelines, and independent reviewers extracted the following information: signalment, lesion location and etiology, treatment, return to soundness or performance, lameness score, ultrasound tissue characterization, and tissue gene expression, composition, mechanical properties, and microstructure. Studies were assessed for risk of bias. A meta-analysis was performed with fixed- or random-effects models and effect size calculated as mean standard deviation or odds ratio, both with 95% confidence intervals, for continuous and dichotomous variables, respectively. Random-effects models were used when heterogeneity was significant. Results: Seventeen studies met the inclusion criteria for further analysis. Return to soundness or performance, lameness score, ultrasound tissue characterization, and microstructure favored MSC therapy. Neither MSC therapy nor control was favored in tissue gene expression, composition, or mechanics. Conclusion: Taken together, these findings suggest that adult MSC therapy for equine tendinopathy and desmopathy has a positive effect on clinical outcomes. Randomized controlled trials using standardized cell isolation, preparation, and dosage, as well as outcome measures, are necessary to confirm benefits in tissue mechanics, gene expression, and extracellular matrix recovery.