- Platelet-rich plasma (PRP) is an autologous concentration of blood-derived human platelets in a small volume of plasma. The types of PRP vary according to the commercial preparation system used, the platelet concentration, or the anticoagulant or activator used. Autologous conditioned plasma is an autologous concentration of human platelets in plasma 2 to 4 times greater than that which is found in blood at baseline. Platelets are important to the normal healing response of tissue by the local secretion of growth factors and recruitment of reparative cells in an area of injury. PRP is theorized to create an optimal healing environment in a region of tissue injury. This is a literature review of currently published studies using PRP in orthopedic injuries. We performed a literature search in PubMed and Medline in April 2013. We concluded that given the number of variations of PRP available and the lack of high-level published studies, there is insufficient evidence to conclusively support its clinical use.