A new study, soon to be printed in the Clinical Journal of Sports Medicine, supports the potential role of Platelet-rich Plasma (PRP) injection as a therapy for knee osteoarthritis. Hospital of Special Surgery, HSS conducted this research on fifteen patients with early osteoarthritis. Each patient received a PRP injection and was subsequently monitored for one year. Clinical assessments were made at baseline (prior to therapy), 1 week, and at 1, 3, and 12 months. In addition, magnetic resonance imaging (MRI) was performed at baseline and again at one-year post injection. This served as an objective measure, which had never been done in any previous PRP study. Research has shown that patients with osteoarthritis can lose about 5% of knee cartilage (tissue that protects joint) per year. However, in this study 73% of patients had no loss of cartilage at the end of one year. Also, patients reported pain reduction and improved function with decreased stiffness. Although this is a case series with 15 patients, it gives researchers confidence to conduct a randomized, controlled trial in the future.