platelet poor plasma (PPP), alpha-2-macroglobulin (A2M), mesenchymal signaling cells (MSCs) for the treatment of common musculoskeletal conditions. Platelet Rich Plasma (PRP) Definition, Processing, and Mechanism of ActionPRP is a biological product defined as a portion of the plasma fraction of autologous blood with a platelet concentration above the baseline found in serum blood 1,2.PRP is thought to exert its effects through the activation of endogenous cellular pathways that stimulate growth factors, singling cells, cyto-and chemokines, interleukins (ILs), and various cell types; all of which play a role in stimulating and enhancing tissue repair processes 2.PRP is obtained by venipuncture, followed by centrifugation which allows for the density-dependent separation of blood components, typically into 3 distinct layers.These include supernatant which is PPP, the buffy coat often considered PRP, and infranant consisting of the red blood cell layer (RBCs).In recent years we have seen a significant increase in the literature describing the preparation of PRP; however, no standardized protocol currently exists to optimize its quantity or application 3456.Platelet Rich Plasma for Joints. Knee JointPRP is commonly used in the treatment of osteoarthritis (OA), with the knee joint having a substantial body of literature 7,8.PRP has been compared to many other conservative injection options for knee OA including hyaluronic acid (HA), corticosteroid injection (CSI), bone marrow aspirate concentrate (BMAC), MFAT and placebo 9,10.In 2021, a meta-analysis of level 1 studies comparing PRP and HA for knee OA was performed and concluded
Negaard et al. (Mon,) studied this question.