Viscosupplementation treatment of arthritis pain.

With the aging of the baby boomer generation, the number of patients with osteoarthritis (OA) is expected to swell, posing treatment challenges. Viscosupplementation, in which hyaluronic acid (HA) is injected into the knee joint, has evolved into an important part of our current therapeutic regimen in addressing the patient with knee pain due to OA. Although suffering from lack of an "evidence-based" approach, and largely funded by industry, there is a growing body of outcome data demonstrating the efficacy of HA in decreasing pain and improving function in patients with knee OA, although no evidence indicates that HA is in any way chondroprotective. The clinical success of HA has led to the ongoing introduction of various forms of HA, although little data are available to justify one over the other.