123 patients with symptomatic knee osteoarthritis were randomized to receive one of three treatments: nonoperative management, arthroscopic debridement alone, or arthroscopic debridement with viscosupplementation applied 3 weeks postoperatively. The purpose of this study was to compare the clinical outcome, functional outcome, and patient satisfaction between the three treatments. Results at 1 year postoperatively indicated significant and prolonged beneficial effects with addition of viscosupplementation. No significant adverse events were reported with this treatment.