A comparative study of the efficacy and safety of hyaluronan viscosupplements and placebo in patients with symptomatic and arthroscopy-verified cartilage pathology.

Viscosupplementation was evaluated in patients with knee pain due to local chondral pathology in a randomised, double-blind, placebo-controlled study of 272 patients. Patients received Synvisc(R) Artzal(R), or placebo by intra-articular injection. At week 26 there were more symptom-free Synvisc(R)-treated patients than placebo patients (44% versus 30%; p=0.048); 43% of Artzal(R) patients were symptom free. Synovial fluid composition, available for 27-30% of patients in each group, showed no notable changes after treatment. Other efficacy endpoints showed no difference between groups. Most adverse events (AEs) were mild, injection-related and resolved shortly after treatment. The most commonly reported treatment-related AEs were arthralgia and arthropathy, experienced by 6% of placebo, 11% of Synvisc(R) and 16% of Artzal(R) patients. Traditional measures of osteoarthritis lack the sensitivity needed to detect clinical change in this population.