Although blood is mainly a liquid (called plasma), it also contains small solid components (red cells, white cells, and platelets.) Platelets are best known for their importance in clotting blood. However, platelets also contain hundreds of proteins called growth factors which are very important in the healing of injuries.
Platelet-rich plasma (PRP) is plasma with many more platelets than what is typically found in blood. The concentration of platelets—and, thereby, the concentration of growth factors—can be five to ten times greater (or richer) than usual.
To develop a PRP preparation, blood must first be drawn from a patient. The platelets are separated from other blood cells, and their concentration is increased during a process called centrifugation. Then the increased concentration of platelets is combined with the remaining blood.
How Does PRP Work?
Although it is not exactly clear how PRP works, laboratory studies have shown that the increased concentration of growth factors in PRP can potentially speed up the healing process. To speed healing, the injury site is treated with the PRP preparation.
PRP can be carefully injected into the injured area. For example, in Achilles tendonitis, a condition commonly seen in runners and tennis players, the heel cord can become swollen, inflamed, and painful. A mixture of PRP and local anesthetic can be injected directly into this inflamed tissue. Afterward, the pain at the area of injection may actually increase for the first week or two, and it may be several weeks before the patient feels a beneficial effect.
What Conditions Are Treated With PRP?
According to current research studies, PRP is most effective in the treatment of chronic tendon injuries, such as chronic Achilles tendonitis. Much of the publicity PRP therapy has received has been about the treatment of acute sports injuries, such as ligament and muscle injuries. PRP has been used to treat professional athletes with common sports injuries.
In our practice, we commonly use PRP in the treatment of:
- Plantar fasciitis
- Achilles tendonitis
- Tendon injuries
- Ankle ligament injuries
The risks associated with PRP are minimal. There may be increased pain at the injection site, but the incidence of other problems—infection, tissue damage, and nerve injuries—appears to be no different from that associated with cortisone injections.