Intra-articular hyaluronic acid preparations for use in the treatment of osteoarthritis.

Intra-articular hyaluronic acid preparations have been available for the treatment of osteoarthritis of the knee for over 15 years. Their use has been limited by cost, difficulties of administration and conflicting evidence of efficacy. Difficulties in conducting adequate clinical trials have resulted in the appearance of multiple meta-analyses whose findings are not congruent. The appearance of a single injection agent and a better understanding of the mechanisms by which this intervention is effective may help to solve this ongoing problem in healthcare research.