Alternatives to IA corticosteroids in high motion joints

Strategies for the management of osteoarthritis (OA) in horses focus on decreasing pain, improving joint function and minimising continued deterioration of joint tissues [1].
The most commonly used intra-articular medications are corticosteroids, hyaluronates and to a lesser extent pentosan polysulfate [2]. Intra-articular therapy with biological agents such as autologous conditioned serum, platelet rich plasma and mesenchymal stem cells have not  only been in the focus of many researchers over the past two decades, but are also commonly used in practice [3]. Relatively new substances for intra-articular treatment of OA in horses are polyacrylamide hydrogel and stanozolol.
Polyacrylamide hydrogel (PAAG) consists of polyacrylamide polymer (2.5%) and water (97.5%). In human medicine it is used for the treatment of stress incontinence in women [4] and to reinforce facial subcutanous tissues [5]. It is not degraded but rather integrated into soft tissues through vessel ingrowth and molecular water exchange [6,7]. First clinical reports on refractory OA cases showed promising results [8] and in a multicentre prospective study on 43 horses with OA, 82.5% of treated horses were lameness-free 2 years after treatment with PAAG [9]. [...]