Intra-articular Hyaluronan Therapy for Symptomatic Knee Osteoarthritis.

Intra-articular hyaluronan therapy (IAHA) is a common but controversial nonsurgical treatment of symptomatic knee osteoarthritis. The overall treatment effect of IAHA for osteoarthritis pain is substantial, but the majority of this benefit is mediated by the placebo effect. Despite the large overall benefit of IAHA when the effect of the hyaluronan is combined with the placebo effect, there is only a small benefit of questionable clinical significance of IAHA compared with intra-articular placebo. Compared with intra-articular corticosteroids, however, IAHA most likely is comparable for long-term pain relief and possibly slightly inferior for short-term pain relief.