INTRAARTICULAR HYALURONAN INJECTIONS IN THE TREATMENT OF OSTEOARTHRITIS OF THE KNEE - A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED MULTICENTER TRIAL

Objective-To assess the effects of intraarticular injections of hyalur onan on symptoms of knee osteoarthritis (OA). Methods-Two hundred and forty patients with symptomatic, radiological knee OA were randomly as signed to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were eva luated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (p ain, function, motion, activity), algofunctional index, and global eva luation by patient and investigator. Analysis was by 'intention to tre at', 'per protocol', and area under the curve principles on unstratifi ed patient groups and for patients stratified into four groups of equa l size by age and baseline algofunctional index. Results-No serious si de effects were reported. At 20 weeks both treatment groups were impro ved compared with baseline, with no difference between unstratified gr oups treated with placebo or hyaluronan. Comparison of treatment group s stratified by age and baseline algofunctional index revealed a signi ficant difference in favour of hyaluronan over placebo (pain, activity , algofunctional index, global evaluations by patient and investigator ) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference bet ween the two treatments for the other three stratified subgroups of yo unger age or fewer symptoms. Similar results were obtained by area und er the curve, intention to treat, and per protocol analysis. Conclusio ns-Patients older than 60 years with knee osteoarthritis and with sign ificant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most Likely to benefit from treatme nt with intra-articular hyaluronan injections.