63 patients with knee osteoarthritis were randomly assigned to receive either sodium hyaluronate (HA) or placebo intra-articular injections. The purpose of this study was to compare the efficacy of hyaluronate injections with placebo injections for reducing pain associated with knee OA. Both pain at rest and pain on movement were measured using a 100mm visual analogue scale (VAS) over 23 week follow-up after the initiation of treatment. Results demonstrated significant within-group pain reduction for the HA group for both pain at rest and pain on movement. Comparison versus placebo demonstrated significantly greater reduction in pain at rest in the HA group from weeks 5 to 23. Though 5 week results for pain on movement also demonstrated significantly greater reduction in the HA group compared to the control group, the values of between-group differences for this outcome at other time points was not reported.