Platelet-rich plasma therapy (PRP) is cutting edge modern medicine that harnesses and amplifies the natural growth factors found in our blood cells to help treat damaged musculoskeletal tissue, reduce pain, and accelerate the body’s natural healing process.
Platelets are found in the blood and are rich in growth factors and other bioactive proteins that are critical for healing and repair of connective tissue in the body. Plasma is the liquid portion of whole blood. It normally provides a medium for red blood cells, white blood cells, and platelets to circulate through the body.
PRP is developed from the patient’s own blood by combing platelets to plasma and decreasing red blood cell concentrations. Approximately two ounces of blood are drawn from the patient and spun in a centrifuge. The spinning process causes the blood to separate into layers, and in this process, platelets are separated from liquid serum and from red and white blood cells. The result is concentrated platelets rich in growth factors. PRP contains five to ten times the number of platelets as whole blood. The concentrate is injected back into the patient’s injured area to speed healing, improve function, and reduce pain.
PRP therapy was developed by hematologists in the 1970s, and it has been extensively studied, tested, and develop in the ensuing years. In the 1980s physicians began to use PRP in surgical procedures, most often in maxillofacial surgery because of its cell growth properties. Since that time its use has expanded to other specialties because it has many applications for healing soft tissues.
Chronic musculoskeletal painful conditions tend to be slow healing and pose treatment challenges. The use of natural, biologic treatments offers exciting opportunities to speed bone, cartilage, and soft tissue healing. For this reason, PRP has gained popularity in orthopedic practices. It is easy to prepare, can be given in a clinic setting, and has an excellent safety profile with a short recovery time.
Platelets are the main component in PRP, and they contain more than 1500 protein-based bioactive factors. These factors include immune system messengers, growth factors, enzymes and their inhibitors, and other factors which can participate in tissue repair and wound healing. It is important to note that PRP is an autologous preparation, which means that it is obtained from the patients’ own blood and therefore there is no risk of cross contamination, disease transmission, or immune reactions. In some tissues, in particular, the musculoskeletal tissues, there is a limited blood supply with slow delivery of nutrients needed for healing. The use of PRP speeds up musculoskeletal repair, by increasing growth factors for healing and possibly improving the blood supply and delivery of nutrients.
The functional properties of PRP are based on the production and secretion of multiple growth factors that are secreted after the platelets are activated. These growth factors regulate cellular processes, including growth and differentiation of undifferentiated mesenchymal connective tissue into mature musculoskeletal cells and collagen. These growth factors also interact with each other to provide activation of different cell signaling pathways that promote healing. Some of the major growth factors in PRP and their functions are:
Platelet-derived growth factor (PDGF) enhances the production of collagen, fibroblasts, and bone cells.
Transforming growth factor (TGF) enhances production of type I collagen, promotes growth of new blood vessels, attracts immune cells, and inhibits bone resorption.
Vascular endothelial growth factor (VGEF) primarily stimulates growth of new blood vessels, but it also helps attract immune cells.
Epidermal growth factor (EGF) stimulates cell proliferation and differentiation and supports cytokine secretion.
Insulin-like growth factor (IGF) promotes cell proliferation and differentiation and stimulates collagen formation.
Fibroblast growth factor (FGF) promotes proliferation of mesenchymal cells, chondrocytes, and osteoblasts, and stimulates their growth and differentiation.
PRP is administered in a clinic setting. The entire procedure takes about one hour. The typical PRP procedure begins with drawing blood from the patient. The blood is then placed in a centrifuge which is a machine that spins and separates the blood into layers. Each layer contains different components such as red blood cells, plasma, and platelets. The concentrated platelet layer is extracted under sterile conditions and placed in a syringe and combined with plasma to get the perfect volume and concentration for the specific musculoskeletal condition to be treated.
The PRP is then injected into the target area under ultrasound guidance. Following the injection, patients are monitored for a short period of time. They can usually resume their usual daily activities with minimal downtime. The patient is advised to limit exercise for about two weeks.
Multiple PRP sessions may be recommended for optimal results.
PRP has broad applications in the field of orthopedics. Improvements in pain and function are generally seen at three to four months post treatment with greater and more sustained improvements around six months. Hundreds of clinical studies have been conducted that demonstrate the safety of PRP. Side effects are minimal and involve pain and tenderness at the injection site for a few days. The results of PRP studies are in contrast with studies of intraarticular corticosteroid outcomes. Steroid injections provide immediate but temporary pain relief along with serious side effects such as cartilage erosion.
