Several studies have shown the positive effects of the autologous "Preparation Rich in Growth Factors" (PRGF) in different clinical situations involving connective tissues and also in OA synovial cells. PRGF is a biological delivery system of a complex mixture of bioactive proteins essential to natural repair including anabolic factors for cartilage such as transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-I). The potential of PRGF to enhance the limited capacity of cartilage to repair itself encouraged the idea of treating degenerative joint conditions with this autologous preparation.