60 females with mild to moderate knee osteoarthritis were randomized to receive either weekly intra-articular injections of a placebo or hyaluronic acid (GoOn) for 5 weeks. The purpose of the study was to evaluate the effects of hyaluronic acid injection over 6 months on MRI-assessed cartilage volume. The results indicated that the hyaluronic acid did not confer a significant effect on cartilage volume at 6 month follow-up over a placebo. Secondary outcomes demonstrated significantly greater improvement in the HA group compared to the placebo group in WOMAC scores, though no significant difference in VAS scores.