Intra-articular 2.5% polyacrylamide hydrogel, a new concept in the medication of equine osteoarthritis: A review.

Recent clinical and experimental trials have demonstrated that intra-articular 2.5% Polyacrylamide hydrogel (PAAG) is highly effective (82.5% free of lameness horses at 2 year follow-up), lasting and safe for the treatment of equine osteoarthritis (OA). Over the last decade, intra-articular 2.5% PAAG has shown to be a potent and promising drug in the medication of OA in horses, as no other single medical treatment for OA has such prolonged efficacy. Most of these studies were presenting some limitations. Preliminary observations on the mechanisms of action of intra-articular 2.5% PAAG support a mechanical effect through integration into the synovial membrane, an increase in joint elasticity possibly reducing overall joint capsule stiffness, and provision of lasting viscosupplementation which contributes to protecting articular surfaces. In addition, no effects on pro-inflammatory cytokines have been observed. Studies also suggest that these positive effects occur in the absence of intra-articular neurotoxicity or fibrosis. The effect on the synovial membrane and joint capsule and the long-acting viscosupplementation represent new concepts in the management of equine OA. Horse; Osteoarthritis, Medication, 2.5% polyacrylamide hydrogel.