Allogeneic chondrogenic-induced mesenchymal stem cells for the treatment of tarsometatarsal lameness in horses.

Abstract

OBJECTIVE: To assess the efficacy of commercial intra-articular blood-derived allogeneic-induced mesenchymal stem cells (CIMSCs) to treat tarsometatarsal lameness in horses. STUDY DESIGN: This was a retrospective cohort study. ANIMALS: Records from 167 adult light breed horses with bilateral tarsometatarsal lameness. METHODS: Horses with tarsometatarsal lameness were retrospectively selected from medical records. Diagnosis followed subjective graded lameness assessment before and after intra-articular analgesia, with graded radiographic tarsal examination. Horses were excluded if they were diagnosed or treated for any other concurrent lameness conditions during the study. Time to last follow-up and time of recurrence of lameness was recorded at veterinary re-assessment. RESULTS: A total of 67 horses were recruited to the CIMSC-treated group and 100 to the corticosteroid (CS)-treated group. Median age was 9&#x2009;years, with no difference in signalment, use or radiographic grade between groups. First re-examination was 38&#x2009;days (95% CI: 38-49), with no difference between groups, CIMSC 42 (35-45), control 34 (25-42). Median follow-up was 438&#x2009;days for CIMSC, 546 for controls. Symptoms of lameness recurred in 86/100 controls compared to 17/67 (25%) CIMSC. Median time to lameness recurring in CIMSC was 336&#x2009;days (95% CI: 239-400), control 90&#x2009;days (95% CI: 80-108), p&#x2009;<&#x2009;.0001. Cox proportional hazard ratio for treatment was 8.35, 95% CI: 4.67 to 14.92, p&#x2009;<&#x2009;.0001. CONCLUSIONS: Lameness was abolished in all treated horses. It recurred significantly less often, and later, in CIMSC-treated horses. CLINICAL SIGNIFICANCE: Intra-articular CIMSC treatment results in prolonged soundness in horses with tarsometatarsal lameness.