Platelet-rich plasma consists of two elements: plasma, or the liquid portion of blood, and platelets, a type of blood cell that plays an important role in healing throughout the body. Platelets are well-known for their clotting abilities, but they also contain growth factors that can trigger cell reproduction and stimulate tissue regeneration or healing in the treated area. Platelet-rich plasma is simply blood that contains more platelets than normal. To create platelet-rich plasma, clinicians take a blood sample from the patient and place it into a device called a centrifuge that rapidly spins the sample, separating out the other components of the blood from the platelets and concentrating them within the plasma.
After creating platelet-rich plasma from a patient's blood sample, that solution is injected into the target area, such as an injured knee or a tendon. In some cases, the clinician may use ultrasound to guide the injection. The idea is to increase the concentration of specific bioproteins or hormones, called growth factors, in a specific area to accelerate the healing process. The mechanism behind PR injections is not completely understood. Studies show that the increased concentration of growth factors in platelet-rich plasma may stimulate or speed up the healing process, shortening healing time for injuries, decreasing pain.
PRP injections may be able to treat a range of musculoskeletal injuries and conditions. For example, chronic tendon injuries such as tennis elbow or can often take a long time to heal, so adding PRP shots to a treatment regimen can help to stimulate the healing process, decrease pain and enable a return to activities sooner.
Clinicians first used PR to accelerate healing after jaw or plastic surgeries. Now, post-surgical PR injections have expanded to help heal muscles, tendons and ligaments, as procedures on these tissues have notoriously long recovery times.
Early studies indicate that PRP injections may help treat osteoarthritis pain and stiffness by modulating the joint environment and reducing inflammation, but research is growing.