49 patients with osteoarthritis of the knee were randomized to receive either a placebo or a high-molecular weight hyaluronic acid preparation administered through an intra-articular injection, weekly for 5 weeks. The purpose of the study was to determine how tolerable and effective this hyaluronic acid preparation (BioHy) was over a period of 5 weeks in comparison to a placebo regimen. The results from this trial indicated a positive trend in the subjective pain parameters in the hyaluronic acid group that did not reach statistical significance when compared to placebo treatment after 20 weeks. Additionally, the treatment was well tolerated, as no systemic adverse events related to the treatment were noted. It should be noted that authors of the study indicated it was underpowered to detect significant differences between groups.