Kaveh Sajadi, MD
PRP, platelet-rich plasma, is touted by some to be a revolutionary treatment with the potential to heal or alleviate any number of ailments, from arthritis to tendinopathies to tendon tears or ruptures. The idea is to use the body’s own “healing” system to repair damaged tissue by amplifying it–increasing the concentration of platelets and their accompanying growth factors, which is then injected into the diseased or injured area.
Platelets are typically activated when a blood vessel is damaged. When the platelet is activated to clot, it also releases many growth factors which are contained within the alpha granules in the platelet. The growth factors present include PDGF (platelet-derived growth factor), important in wound healing, VEGF (vascular endothelial growth factor), which recruits the body to form new blood vessels, as well as many other signaling factors and cytokines.
To use PRP, the process begins by drawing a patient’s whole blood, typically approximately 30-60ml, depending on the indication. The blood is then mixed with an anticoagulant and placed in a centrifuge to separate it into three layers. The three layers consist of red blood cells at the bottom of the tube; platelet poor plasma at the top; and the “buffy coat,” which contains the concentrated platelets, leukocytes or white blood cells is in the middle. The PRP, taken from the buffy coat, can then be injected directly to the desired site or it can be “activated” first by adding a mixture of calcium chloride or thrombin, which causes the plates to degranulate and release growth factors.
Clinical studies are limited for several reasons. One, every patient’s PRP is unique, and comparing PRP from one person to another is not possible. Second, the composition of a person’s PRP can also be influenced by medications. Furthermore, numerous preparation techniques make comparisons between systems and clinical studies difficult to interpret. One of the primary differences in preparations is whether the PRP is leukocyte rich (LR = neutrophil concentration above whole blood baseline) or leukocyte poor (LP = neutrophil concentration below whole blood baseline). These different formulations may be very important for the particular indication for which they are being used.
Clinical uses for PRP are many and continue to be investigated. It has been used to treat tendinopathies, partial tendon tears, complete tendon tears, arthritis, and as a surgical adjunct to aid wound healing, tendon healing and reduce pain.
Clinical uses for PRP are many and continue to be investigated. It has been used to treat tendinopathies, partial tendon tears, complete tendon tears, arthritis, and as a surgical adjunct to aid wound healing, tendon healing and reduce pain. Scientific studies lag behind clinical usage and, as mentioned previously, are very limited due to the wide variability in composition, preparation and indication. Additionally, most studies have focused on clinical outcomes and not structural or anatomic changes that may or may not occur. The best clinical evidence thus far is related to lateral epicondylitis, or tennis elbow. LR-PRP has been shown to provide significant improvement in pain and function at the six-month follow-up compared with local anesthetic injection.1 There is also strong Level-1 evidence to support LP-PRP in osteoarthritis of the knee in reducing pain and improving function,2 and it may be beneficial in the treatment of plantar fasciitis as well.3 Evidence also shows LR-PRP has been used to successfully treat partial ulnar collateral ligament tears in overhead athletes.
Choosing the right PRP system plays a critical role in the success of your treatments. While there is no clear consensus on the best preparation, it is becoming clear that LR or LP PRP may be better in certain indications. LR-PRP may be beneficial where a strong inflammatory response is desired, such as chronic tendinopathies. LP PRP seems to be more beneficial in treating the symptoms of osteoarthritis and may help the healing of the rotator cuff tendon after surgery. A system that enables the surgeon to choose the right formulation for the right patient puts you in the best position to help.
- Mishra AK, et al. Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients. Am J Sports Med. 2014;42: 463–71. Large multicenter double-blind randomized controlled trial for PRP and lateral epicondylitis, demonstrating significant symptomatic and functional benefit of PRP injection.
- Smith PA. Intra-articular autologous conditioned plasma injections provide safe and efficacious treatment for knee osteoarthritis: an FDA-sanctioned, randomized, double-blind, placebo controlled clinical trial. Am J Sports Med. 2016;44:884–91. Double-blind RCT demonstrating safety and efficacy of PRP for knee OA compared to saline placebo.
- Le ADK, et al. Current Clinical Recommendations for Use of Platelet-Rich Plasma. Curr Rev Musculoskelet Med. 2018;11(4):624–634. doi:10.1007/s12178-018-9527-7
Kaveh Sajadi, MD, practices orthopaedics with Kentucky Bone and Joint Surgeons and is an instructor in the University of Kentucky’s residency program. He completed his residency at the Campbell Clinic and his fellowship at the NYU Langone Hospital for Joint Diseases. Dr. Sajadi is a frequent instructor at Exactech domestic and international shoulder courses.