160 patients with knee osteoarthritis were randomized to receive platelet-rich plasma injections or hyaluronic acid injections. This was done to assess the effects of each treatment on clinical outcomes and patient quality of life over a 52-week period. Quality of life and function were measured through the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the SF-36 questionnaires. Results indicated that patients who had received the platelet-rich plasma injections experienced significantly greater improvement in questionnaire results than patients who had received hyaluronic acid injections.