Intra-articular hyaluronic acid (viscosupplementation) for knee osteoarthritis.

(1) In viscosupplementation, a glycosaminoglycan (GAG) called hyaluronic acid (HA) is administered via intra-articular (IA) injection for patients with knee osteoarthritis (OA). (2) Evidence suggests modest short-term reductions in pain and improvements in function, and no superiority among HA products. (3) Adverse events are rare, benign, temporary, and likely associated with the IA injection. (4) Economic analyses of mixed quality suggest that HA may be cost effective compared with usual care. (5) Clinical practice guidelines and evidence suggest that this approach is most suitable for patients with mild to moderate knee OA, and in those for whom other approaches are contraindicated, or have failed.