Platelet Rich Plasma (PRP) and Regenerative Medicine in Orthopedics and Sports Medicine
Platelet Rich Plasma (PRP) therapy
PRP is a relatively new treatment designed to aid in the healing and regeneration of soft tissues such as tendons and ligaments. To fully understand the benefits of PRP therapy it is first useful to have some understanding of the basic science behind tendon and ligament injuries.
Tendon & Ligament Injuries
Tendons and ligaments are made up of fibers of collagen. When these fibers are stretched or torn we may refer to the injury as a “pull”, “tear”, “sprain” (ligament) or “strain” (tendon). These structures are vascular which means there are blood vessels in them. Thus, when they are injured they bleed. If there is enough bleeding we may notice bruising around the area of injury. Blood flow to the area increases to aid in healing. The blood carries platelets and growth factors that allow for healing of the tissue by creating new collagen fibers. These new fibers need to be constructed in an organized, layered fashion to heal correctly and allow the ligament or tendon to regain its proper strength and flexibility.
The Healing Process
Sometimes, however, the healing process does not work correctly and instead of forming healthy collagen fibers there is significant scar tissue that develops in its place. One of the risk factors for this is not getting enough blood flow to the area to provide those platelets and healing factors. The development of scar tissue even further prohibits proper blood flow as new capillaries and other small blood vessels can’t penetrate through the scar tissue to provide blood flow to the injured area. The new development of small blood vessels is called “angiogenesis” or “neovascularization”. When scarred or disorganized tissue inhibits this process the blood flow to the area becomes “blocked”. This means that the tissue will never really have the opportunity to heal correctly. That is why sometimes ligament and tendon injuries heal and other times they do not.
Results of Incorrect Healing
When these injuries don’t heal patients often become frustrated. Patients may try anti-inflammatories and other pain medications, topical creams and gels, braces, physical therapy, massage, acupuncture and cortisone. These therapies may try to treat pain and inflammation but they don’t treat the underlying problem of scar tissue, disordered fibers and poor angiogenesis (blood flow). The result is many patients may give up and live with pain and disability or may end up with surgery.
PRP therapy is one possible solution to this problem. In PRP treatment the patient’s own blood is taken with a simple blood draw. Using a special centrifuge machine this blood is spun down to separate out and concentrate the platelets and growth factors that are essential for tissue healing. This small amount of fluid with concentrated platelets and growth factors is called platelet rich plasma (PRP). Nothing else is added to the patient’s own blood products so there is no risk of allergy, reaction or rejection. PRP therapy is a purely natural process using the body’s own healing factors. The trick is getting them to the right place.
Locating the Injured Area
The physician then uses a diagnostic ultrasound machine to identify the area within the ligament or tendon that is injured. The newest ultrasound technology provides resolution to see every millimeter of the collagen fibers as well as scar tissue and blood flow to the area. The physician is then able to use a needle to inject the PRP directly into the injured area and even between tightly packed collagen fibers. The PRP can even be injected directly into very small tears that are sometimes not apparent on MRI. Once these platelets and growth factors are in the area of injury they then become activated. They also recruit other healing proteins and factors to the area and healing and regeneration of the tissue can now begin.
History of PRP Therapy
This therapy has been used extensively in Europe for several years and is now becoming more popular in the U.S. as more people become aware of its potential benefits and as more research is being done. But the idea of getting blood to an injured area is not new. For years many people have tried needling tissue or injecting an irritant into the tissue (prolotherapy) to attempt to increase blood flow to the injured area. Now with the development of PRP we can actually get the specific healing factors within the blood to the injured area. This not only allows for healing of injuries which may not otherwise heal, but it also speeds up recovery of injuries which may eventually heal over a longer period of time. Thus PRP therapy is a great option for two different patient populations. One is the patient with the chronic injury that never seems to go away. The other is the patient with an acute injury which might otherwise take 8-12 weeks to heal and is looking to do something to “speed up” the recovery process. That is why PRP has become so popular among athletes and there have been many media reports of elite athletes receiving PRP treatment for injuries that occur mid-season or even right before big events such as the Superbowl. But PRP treatment is not just for athletes.
PRP therapy can be used with great success for the following conditions: