A Closer Look At Platelet-Rich Plasma For Achilles Tendon Pathology
As orthobiologic technology continues to advance, these authors discuss the theory behind platelet-rich plasma (PRP), offer a thorough review of the literature on PRP for Achilles tendon injuries and provide insights from their clinical experience on the role of this emerging modality.
The use of orthobiologics in the treatment of foot and ankle injuries, both in the clinical and surgical venues, is significantly increasing. The clinician and the surgeon continue to seek better ways to accelerate and mediate the healing of bone and soft tissue while incorporating less invasive techniques.
The use of autologous platelet-rich plasma (PRP) by foot and ankle specialists over the last few years has emerged in the forefront of biologic tools in this endeavor. Physicians and clinicians have utilized PRP over the last four decades. Researchers have investigated the use of PRP in the treatment of tendon injuries, chronic wounds, ligamentous injuries, cartilage injuries, muscle injuries, and bone augmentation (intraoperative fusions and fracture repair). The use of PRP is based on the theory that increased concentrations of autologous platelets yield high concentrations of growth factors and other proteins, which will subsequently lead to enhanced healing of bone and soft tissue on a cellular level.
Platelet-rich plasma is the concentration of platelets derived from the plasma portion of centrifuged or filtered autologous blood. Surgeons can then use this platelet rich solution as an adjunct to healing as with a fresh surgical fusion or to reinstate healing as with chronic tendon injuries. Platelet-rich plasma and related products have different labels throughout the literature including platelet-rich concentrate, platelet gel, preparation rich in growth factors (PRGF), platelet releasate and platelet-leukocyte-rich gel (PLRG).
When one acquires the PRP, another product may or may not activate it. Platelet rich plasma without activation is usually reserved for the treatment of tendon, muscle and other soft tissue. In regard to PRP activated into a gel or fibrin sealant, podiatrists can use this clinically and intraoperatively for tendon augmentation, wound healing and bone augmentation. There have been several studies investigating the efficacy of PRP and its applications.1
Understanding The Theoretical Benefits Of PRP
Essentially, one uses PRP to increase the concentration of platelets to an injured site. In an acute injury, platelets are normally activated during the inflammatory phase to begin healing. The addition of PRP in the acute injury increases the concentration of platelets at the local tissue above the baseline. Chronic injuries that have failed conservative therapies presumably have ceased the inflammatory phase, have a paucity of platelets and a decrease in healing potential.
The use of PRP in these situations would provide two beneficial results. First, the simple act of injecting PRP for tendon, ligament or muscle injuries will stimulate the tissue and restart the inflammatory process, thereby making the chronic injury into a “new” acute injury. Second, the addition of autologous concentrations of platelets theoretically augments the healing process. This new injury now has a known starting point and can be placed in a controlled post-injection environment (i.e. immobilization, bracing or non-weightbearing). During this time, the use of anti-inflammatory medications and therapies are restricted so as not to reverse the desired effect.
How One Acquires PRP
To acquire autologous PRP, one would collect blood from the cubital vein. The amount of blood acquired depends on the clinical application (treatment area) and desired concentration. Clinicians would then separate the platelets from the plasma via centrifugation or filtration. Many different systems are available on the market today to obtain the PRP.