The Effects of Platelet-Rich Plasma on Cartilage: Basic Science and Clinical Application

Platelet-rich plasma (PRP) is emerging as a biological therapy for the treatment of cartilage injuries and for intra-articular application to address knee pain. Basic science studies indicate that PRP stimulates cell proliferation and the production of cartilage matrix by chondrocytes and bone marrow–derived mesenchymal stromal cells and increases the production of hyaluronic acid by synoviocytes. In preclinical animal model studies, PRP slows the progression of osteoarthritis, but there are mixed results after the use of PRP to facilitate the repair of chondral or osteochondral defects. Clinical studies indicate that PRP-bone marrow–derived stromal cell constructs aid in the repair of chondral defects. A clinical benefit from PRP was also shown for 1 year after intra-articular injection in patients suffering from knee pain. Although most studies support the clinical use of PRP for the treatment of cartilage injury and joint pain, improved classification schemes for PRP and more extensive testing and reporting on the contents of the PRP preparation being applied in the study would aid in the development of treatment protocols.