Intra-articular injections of 750 kD hyaluronan in the treatment of osteoarthritis: a randomised single centre double-blind placebo-controlled trial of 91 patients demonstrating lack of efficacy.

OBJECTIVE To determine the safety and efficacy of intra-articular injections of hyaluronan in the treatment of osteoarthritis of the knee. METHODS A randomised double-blind placebo-controlled trial was carried out on 91 patients with radiologically confirmed osteoarthritis of the knee who were recruited from the outpatient clinics. RESULTS It was found that weekly intraarticular injections of 20 mg of hyaluronan of M(r) = 750,000 (Hyalgan) in 2 ml of buffered saline performed no better than the inert vehicle alone over a five week period. The principal side effects of a transient increase in pain and swelling in the affected knee was observed in 47% of the treatment group compared with 22% of the placebo group. A few patients with radiologically mild disease treated with Hyalgan appeared to experience medium to long-term symptomatic improvement over matched placebo controls as judged by a delayed return to previous NSAID therapy or analgesia other than paracetamol. Patient numbers in the survival groups, however, were too small to be meaningful. CONCLUSION It is concluded that intraarticular administration of this preparation of 750 kD hyaluronan offers no significant benefit over placebo during a five week treatment period, but incurs a significantly higher morbidity, and therefore has no place in the routine treatment of osteoarthritis.