Platelet-rich plasma (PRP) injection has emerged as a treatment alternative for many musculoskeletal conditions. Although concentrated platelet therapy, including PRP, has been used for 20 years, it has recently been popularized by the media after its positive effects were reported to be responsible for an American professional football player's accelerated return to play and subsequent victory in the 2009 Super Bowl.
Platelet rich plasma therapy is an innovative treatment that can be used in management of a variety of chronic pain conditions including tendon injuries, muscle injuries and ligament injuries. The potential role of PRP in healing musculoskeletal injuries is an exciting frontier that may lead to newer improved therapies. However, further studies are needed to establish effectiveness, indications and protocols for PRP application in the treatment of musculoskeletal injuries. At Pain Spa Dr Krishna is very experienced in performing interventional pain procedures, including platelet-rich plasma therapy. Dr Krishna always performs injections under ultrasound or fluoroscopy guidance for greater accuracy and improved safety.
At Pain Spa Dr Krishna is very experienced in performing interventional pain procedures, including platelet-rich plasma therapy. Dr Krishna always performs injections under ultrasound or fluoroscopy guidance for greater accuracy and improved safety.
PRP is defined as a platelet concentration higher than the physiologic platelet concentration found in healthy whole blood. Some authors have adopted a more objective definition of five times the platelet concentration of whole blood. The ability to concentrate platelets allows a higher concentration of the bioactive growth factors reported to promote healing. There are currently many clinical applications of PRP, including bone healing in oral maxillofacial surgery, postoperative wound healing, and postoperative rotator cuff repair integrity in orthopedic surgery. The positive effects in these intraoperative applications have stimulated the use of PRP in the sports medicine outpatient clinic setting, mostly for chronic tendinopathies.
The recent explosion of the clinical use of PRP has outpaced evidence-based research. Few randomized controlled studies and smaller anecdotal case reports document clinical success of PRP.
The average platelet concentration of whole blood is 200,000 per μL (normal range 150,000–350,000 per μL). Platelets are small anucleated cytoplasmic fragments of megakaryocytes that are commonly thought of as the responsible agents for hemostasis. Although the platelet is central to the coagulation cascade, it is also essential to tissue healing. The first step of the healing process is clot formation and platelet activation. After platelet activation, many growth and differentiation factors are released from the α-granules, which are storage units found in platelets. Ninety-five percent of the existing factors are released within 10 minutes of clot formation, whereas the rest of the growth factors are released as they are formed over several days.
The potential benefits of PRP are thought to rely on the intrinsic properties and interplay between the concentrated growth factors. Some of these important growth factors include platelet-derived endothelial growth factor, transforming growth factor–β, vascular endothelial growth factor, fibroblast growth factor, epidermal growth factor, and insulin-like growth factor -1. The complex interactions of these growth and differentiation factors, along with adhesive protein factors such as fibronectin and vitronectin, are what is responsible for the healing response; promoting the long regenerative process of chemotaxis, cell proliferation, removal of tissue debris, angiogenesis, extracellular matrix formation, osteoid production, and collagen synthesis.
The working definition of PRP is 1,000,000 per μL platelet count, which is five times the normal concentration found in whole blood. PRP is commonly prepared using a centrifuge. There are different types of centrifuge methods and systems and no study till date has compared the effectiveness of different PRP preparation systems or platelet concentrations against one another for any indication.
Injections are generally avoided in patients with systemic infection or skin infection over puncture site, bleeding disorders or coagulopathy and allergy to local anaesthetics or any of the medications to be administered. In addition PRP therapy should be avoided in patients with history of malignancy. Nonsteroidal antiinflammatory drugs should be avoided 2 weeks prior and at least 2 weeks after the procedure so as to not inhibit the effects of growth factors and the healing response.
The procedure is usually done on an outpatient basis. Patients need to be aware that the outcome of the procedure is variable and they may not receive the desired benefits. Similarly, they must be aware of the transient nature of the therapeutic benefits and that they may need repeated injections. A series of 3 injections with platelet rich plasma is usually recommended at 4-weekly intervals. The procedure involves the following steps:
Step1: collection of blood from the patient through venipuncture
Step2: Centrifugation to separate the whole blood into three layers: RBCs (bottom layer), platelet-poor plasma (top layer) and platelet concentrate that contains WBCs (middle layer)
Step3: Activation of platelet rich plasma with calcium and injection into the damaged tissues
Complications are rare, particularly if the injections are performed using a precise needle-positioning technique. Possible complications include bruising, infection, hematoma, nerve injury and reaction to the injectates. Infection can be avoided with appropriate aseptic precautions. Post-procedural pain flare-up may occur because the injection of PRP induces local inflammation.