An assessment of the effectiveness of hyaluronic acid and polyacrylamide hydrogel in horses with osteoarthritis: Systematic review and network meta-analysis

For several years, hyaluronic acid (HyA) and, more recently, polyacrylamide hydrogel (PHyd) have been used to reduce lameness and pain caused by osteoarthritis. However, there is still a lack of scientific evidence of the efficacy of these substances to allow veterinary experts to make decisions about their use in horses. The objective of this study was to evaluate, through a systematic review and network meta-analysis (NMA), the efficacy of HyA, associated or not with other drugs, and PHyd in relieving lameness in horses with osteoarthritis. The searches for primary studies were conducted on four search platforms. The efficacy of HyA and PHyd was estimated through the relative risk difference method. Heterogeneity was observed in the efficacy of HyA, indicating long-term ineffectiveness of this drug when associated or not with anti-inflammatory drugs. In contrast, the results indicate that PHyd is an effective alternative therapy, with a long period of action in reducing lameness in horses with osteoarthritis. This study provides evidence that the application of PHyd and HyA is effective in reducing lameness caused by osteoarthritis in horses at different time periods, where PHyd has a longer time of action. •Infiltrations of hyaluronic acid and polyacrylamide hydrogel are able to decrease lameness in horses with osteoarthritis;•The polyacrylamide hydrogel has a high rate of success in treatment of lameness in horses with osteoarthritis;•There is no scientific evidence that hyaluronic acid is effective for a long period of time.