Autologous Platelet Concentrates as a Treatment of Horses with Osteoarthritis: A Preliminary Pilot Clinical Study

The clinical effect of the intra-articular injection of an autologous platelet concentrate (PC) in four horses with osteoarthritis was evaluated. The degree of lameness and joint effusion and clinical follow-up were recorded. Three injections of PC were performed at 2-week intervals. Horses were evaluated before each injection and two months after the last treatment. Clinical follow-up was conducted for 1 year. Count of platelets, leukocytes, and determination of transforming growth factor beta-1 (TGF-β1) levels per milliliter PC were performed, as well as leukocyte count, cytology, and protein levels in synovial fluid. PC produced a statistically significant improvement in both the degree of lameness and joint effusion (P < .05). The most marked improvement was observed 2 months after the last treatment and apparently persisted for 8 months. A mean of 250 ± 71.8 × 106 platelets, 8.68 ± 3.78 leukocytes × 106, and 12,515 ± 2,443 pg of TGF-β1 per milliliter PC were obtained. The evaluated synovial fluid parameters remained between normal values. No adverse clinical signs resulted from this treatment. Despite the seemingly positive effects of this substance, the clinical use of PC cannot be recommended until further studies with higher numbers of cases and longer follow-up can be undertaken.