Platelet Rich Plasma

Platelet-Rich Plasma (PRP)

During the past several years, much has been written about a preparation called platelet-rich plasma (PRP) and its potential effectiveness in the treatment of injuries

Platelet rich plasma therapy (PRP) involves removing autologous blood and enriching the platelet content prior to injection at sites of injury. Clinicians in Italy introduced PRP in 1987 for autologous transfusion for cardiac surgery patients. Later, orthopaedic surgeons adapted PRP to promote adherence of bone graft material and to prevent tissue drying. Clinicians developed PRP as a treatment for musculoskeletal pain because platelets are a rich source of growth factors that may be beneficial for healing.

Many famous athletes (Tiger Woods, Rafael Nadal) — have received PRP for various problems, such as sprained knees and chronic tendon injuries. These types of conditions have typically been treated with medications, physical therapy, or even surgery. Some athletes have credited PRP with their being able to return more quickly to competition.

What Is Platelet-rich Plasma (PRP)?

Although blood is mainly a liquid (called plasma), it also contains small solid components (red cells, white cells, and platelets.) The 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.

PRP is plasma with high concentration of platelets than what is typically found in blood. The concentration of platelets — and, thereby, the concentration of growth factors — can be 5 to 10 times greater (or richer) than usual.

Most of the studies on the efficacy of PRP demonstrated that PRP is not associated with serious adverse events and may provide variable improvement in pain scores for specific musculoskeletal conditions. PRP is thus a variably effective but safe procedure that is widely available.

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.

The efficacy of PRP depends on the PRP source, preparation technique, administration and the recipient. Younger healthier patients heal faster than older patients who are not in good clinical condition, and young patients likely have a greater regenerative capacity to produce platelets. Elite athletes are also more physically active, and this increases blood flow and places more strain on the injured tissue.

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. Platelets are not passive carriers of growth factors, as was presumed in the original rationale for PRP use, but they actively initiate healing through a selective release of proteins and chemokines in response to the wound microenvironment.To speed healing, the injury site is treated with the PRP preparation. This can be done in one of two ways:

  • 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. Afterwards, 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
  • PRP may also be used to improve healing after surgery for some injuries. For example, an athlete with a completely torn heel cord may require surgery to repair the tendon. Healing of the torn tendon can possibly be improved by treating the injured area with PRP during surgery. This is done by preparing the PRP in a special way that allows it to actually be stitched into torn tissues.

What Conditions are Treated with PRP?

Research studies are currently being conducted to evaluate the effectiveness of PRP treatment. At this time, the effectiveness of PRP therapy can be termed as variable. Factors that can influence the effectiveness of PRP treatment include:

  • The area of the body being treated
  • The overall health of the patient
  • Whether the injury is acute (such as from a fall) or chronic (an injury developing over time)

Chronic Tendon Injuries

According to the research studies currently reported, PRP is most effective in the treatment of chronic tendon injuries, especially tennis elbow, a very common injury of the tendons on the outside of the elbow. The use of PRP for other chronic tendon injuries — such as chronic Achilles tendonitis or inflammation of the patellar tendon at the knee (jumper's knee) is promising

Acute Ligament and Muscle Injuries

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 like pulled hamstring muscles in the thigh and knee sprains. There is no definitive scientific evidence, however, that PRP therapy actually improves the healing process in these types of injuries.


More recently, PRP has been used during certain types of surgery to help tissues heal. It was first thought to be beneficial in shoulder surgery to repair torn rotator cuff tendons, and although there appears to be some benefit of PRP injection

Knee Arthritis

Some initial research is being done to evaluate the effectiveness of PRP in the treatment of the arthritic knee. It is still too soon to determine if this form of treatment will be any more effective than current treatment methods.


PRP has been used in a very limited way to speed the healing of broken bones. So far, it has shown no significant benefit

Treatment with PRP could hold promise, however, further research studies are necessary. PRP appears to be effective in the treatment of chronic tendon injuries about the elbow and the risks associated with it are minimal. There may be increased pain at the injection site, but the incidence of other problems — infection, tissue damage, nerve injuries — appears to be no different from that associated with cortisone injections.

If you have any question concerning the PRP injections such as risk, benefits, likely outcome or complication please do not hesitate to contact a team member at Joint & Sports Clinic.