Platelet-rich plasma (PRP), a therapy used to help heal surgical wounds and tendon injuries, may also relieve symptoms of early knee osteoarthritis (OA), according to a new study out of the Hospital for Special Surgery (HSS) in New York. Researchers there say patients with knee OA reported significantly improved pain and function for 12 months after a single PRP injection. The findings, published online in Clinical Journal of Sports Medicine, also suggest that PRP may slow joint damage if administered early in the course of the disease.