A physician treats a patient using PRP.

Muscle and tendon injuries are common in most active individuals, from the professional athlete to the weekend warrior. According to the World Health Organization (WHO), musculoskeletal injuries are the most common cause of severe long-term pain and physical disability, and affect hundreds of millions of people around the world. In the U.S., approximately 45% of all musculoskeletal injuries involve soft tissue including tendons and ligaments.

Treatment of these injuries has evolved slowly over the years. In recent months there has been much media attention on one of the latest emerging therapies - Platelet Rich Plasma (PRP), a treatment option that has been shown to accelerate the healing process of musculoskeletal injuries. Recent and emerging studies suggest that PRP may eventually play a central role in the treatment of common sprain and strain injuries.

What is PRP?
PRP treatment is a process of using a patient’s own blood products to facilitate healing. A small amount of the patient’s whole blood is drawn into a syringe containing an anticoagulant. The blood is then centrifuged in a special device to separate the platelet-rich buffy coat, which is suspended in plasma between the red blood cell layer and the platelet-poor plasma fraction. Using these techniques, it is possible to achieve platelet concentrations up to eight times higher than normal, which can then be injected into injured soft tissue.

To more precisely place the therapeutic injectate, a dynamic musculoskeletal ultrasound is often used. Once the exact location is determined, the patient is prepped with a local anesthetic. A PRP injection is most effective when spread using a “peppering” technique, injecting the PRP in a clock-like manner to better cover the injured area. Tendons may also be fenestrated and the PRP seeded into these pockets.

Following the injection, patients may experience worsening pain for several days. It is important to avoid ice and anti-inflammatory medications at this stage, as these interventions may reverse the desired inflammatory response. Pain may be controlled with acetaminophen or other analgesics. There have been no reported adverse reactions to the treatment in the research literature thus far, and it is widely accepted as a safe procedure.

PRP: A Paradigm Shift
To understand the science of PRP it is important to understand the physiological principle of healing. Platelets were initially known to be responsible for blood clotting. In the last 20 years we have learned that when activated in the body, platelets release healing proteins called growth factors. There are many growth factors with varying roles, which cumulatively coordinate tissue healing. Some of the main components concentrated in PRP are Platelet Derived Growth Factor (PDGF), Transforming Growth Factor beta (TGFb), Epidermal Growth Factor (EGF), Vascular Endothelial Growth Factor (VEGF), and Insulin Growth Factor (IGF). Together, these growth factors work to increase blood perfusion, enhance collagen synthesis, increase the rate of epithelial and granulation tissue production, improve bone growth and induce an antimicrobial effect.

Higher concentrations of white cells in PRP also confer additional healing cytokines while providing antibacterial activity. Steroid use has long been a central theme in the treatment of various injuries, which in fact impedes this normal healing cascade. PRP in turn induces inflammation and promotes natural healing. This intervention, therefore, represents an important paradigm shift from our common strategy of reducing inflammation to avoid pain.

Applications, Research and the Future of PRP
For over twenty years, PRP has been utilized among various specialty groups including orthopedics, dentistry, otolaryngology, neurosurgery, ophthalmology, urology, wound healing, cosmetic, cardiothoracic, and maxillofacial surgery. Although PRP therapy has been used an acceptable intervention in these fields for decades, it has recently gained popularity in the United States for the treatment of various sports injuries. Recent literature has suggested its efficacy in various surgical and non-surgical applications. PRP has been shown to accelerate bone graft formation in mandibular surgeries, improve fusion rates in spine surgery, and increase efficacy of knee and ankle surgeries. Non-operative PRP studies have shown positive results in the treatment of lateral epicondylitis, infra-patellar tendonitis and knee osteoarthritis.

Despite convincing evidence of its efficacy, much work remains to be done in exploring the application and utility of PRP. Our regeneration lab at the MedStar National Rehabilitation Hospital has recently been awarded a grant to explore the application of PRP in shoulder tendinopathies. This and future studies will provide great insight into this promising treatment, paving the way to a better understanding of common and disabling sports injuries.

More: Platelet Rich Plasma: Frequently Asked Questions