Bone Marrow Mononuclear Cell for Equine Joint Disease

Osteoarthritis (OA) can be debilitating and career-ending for horses. Current treatments offer temporary and symptomatic relief, but potentially deleterious side effects. Bone marrow mononuclear cells (BMNC) are a rich source of macrophage progenitors that are anti-inflammatory and promote inflammation resolution. The objective of this study was to evaluate the ability of intra-articular BMNC therapy to improve clinical signs of naturally occurring equine OA. Horses presenting with clinical and radiographic evidence of moderate OA in a single joint were randomly assigned to 1 of 3 treatments: saline (negative control), triamcinolone (positive control), or BMNC (treatment group). Horses were subjectively and objectively evaluated for lameness and synovial fluid collected (cytology and cytokine/growth factor quantification) at 0, 7, and 21 days post-injection. Data were analyzed using General Estimating Equations with significance set at P<0.05. There were no adverse effects noted in any treatment group. No significant differences in synovial fluid cytology parameters, objective/subjective lameness scores, nor joint circumference were found between treatment groups at any time point. Within treatment groups, joint circumference did not change over time for saline- and triamcinolone-treated horses. However, joint circumference and objective lameness decreased significantly within BMNC-treated horses between Days 0 and 21 and Days 7 and 21. Lameness improved in saline-treated horses from 0 to 21 days, but did not improve in triamcinolone-treated horses. The decreased lameness and lack of adverse effects in the BMNC-treated horses in our study support a larger clinical trial using BMNC.