Intra-articular hyaluronan injections for the treatment of osteoarthritis of the knee: a randomized, double blind, placebo controlled study.

Objective: Hyaluronic acid (HA) polymers have been found to be useful as viscosupplements for the treatment of osteoarthritis (OA) in a number of clinical studies. It appears that HA with high molecular weights (HMW) are more effective than low molecular weight HA polymers.
Methods: A single blind, initial randomized study was conducted involving two randomly selected patient groups, which received injections of either placebo or BioHy, a highly purified HMW HA produced by bacterial fermentation. HA was administered intra-articularly and several functional tests, including pain level, stiffness, and physical function, were used to score efficacy at various intervals throughout the study.
Results and Conclusion: The results through week 20 indicate that BioHy provides relief for osteoarthritic patients without causing adverse effects, although the study was not sufficiently powered to obtain statistically significant differences between the treatment groups.