Does Platelet Rich Plasma (PRP) Have A Role in Treatment of Tendon Injuries?
Tendinopathy (tendon injury) is a common condition often related to a multitude of factors, including micro trauma, excessive loading (overuse), and aging. It is damage to the tissue that connects our muscles to our bones. Platelet-rich plasma (PRP) is a popular and relatively new treatment option for this injury. Although its basis of effectiveness is building, it still remains inconclusive for its use in tendon rehabilitation.
How does PRP work?
PRP therapy is made from an increased concentration of platelets that have been obtained from the patient through drawing of their blood. Once the blood is drawn from the patient, it is spun (centrifuged) until appropriately separated into 3 layers: platelet poor plasma, platelet rich plasma and red blood cells. When spun, the heavier PRP is deposited at the bottom of the tube, and a platelet gel is subsequently created. The process produces a 3-5x greater platelet concentration than normally found in the body. The PRP solution is then injected into the patient’s injured tissue. A number of human tissue in vitro studies have demonstrated that platelets release various growth factors, such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), transforming growth factor beta (TFG-beta) and hepatocyte growth factor. These growth factors are thought to be responsible for PRP’s beneficial effects while promoting tendon repair.
Below you will find the most commonly reviewed uses of PRP treatment.
Lateral Epicondylitis (Lateral Elbow Pain)
Studies have demonstrated a 25-60% decrease in visual analogue scale (VAS) or commonly known as “subjective pain scores”. One large, multi-centred randomized control trial (RCT) of leucocyte-containing PRP (L-PRP) demonstrated significantly greater pain relief in the PRP group at multiple time intervals. In spite of this, a 2014 meta-analysis concluded that there is no evidence that PRP is effective in the treatment of long standing lateral elbow pain.
Achilles Tendinopathy
The data for this condition is mixed, due to small sample sizes and differing treatment protocols. Recent RCT and imaging studies on patients with chronic, mid-portion Achilles tendinopathy showed no difference between PRP injected and saline control groups. Still, some additional studies have found PRP therapy to speed return to sporting competition when combined with surgical intervention. However, the current data is not conclusive enough to justify the use of PRP in patients suffering from recurring Achilles tendinopathy.
Patellar Tendinopathy (Frontal Knee Pain)
A small study evaluated the use of ultrasound-guided PRP injections in athletes suffering from patellar tendinopathy, and demonstrated up to 80% improvement in various pre and post outcome scores. Similar findings were shown in studies comparing PRP to physical therapy and extracorporeal shockwave therapy. The above mentioned data supports the use of PRP to treat reoccuring, insertional patellar tendinopathy.
In summary, the available data does not support the use of PRP as a first-line treatment for chronic tendinopathy. This is likely because of the vast diversity of patient populations, tendinopathy sub-types (I.e Dysrepair, Degenerative, Reactive) composition of PRP injection solutions, and injection protocols. The state of the current evidence is largely inconclusive. PRP might have therapeutic potential in chronic tendinopathies that have not responded to standard non-operative treatment, particularly in the case of chronic patellar tendinopathy.
Like many interventions, PRP might be beneficial in the right patient at the right time.
References
Nourissat G, Ornetti P, Berenbaum F, Sellam J, Richette P, Chevalier X. Does platelet-rich plasma deserve a role in the treatment of tendinopathy?. Joint Bone Spine. 2015 Jul 1;82(4):230-4
de Vos RJ1, Windt J, Weir A. Strong evidence against platelet-rich plasma injections for chronic lateral epicondylar tendinopathy: a systematic review. Br J Sports Med 2014; 48: 952–6.
Creaney L, Wallace A, Curtis M, et al. Growth factor-based therapies provide additional benefit beyond physical therapy in resistant elbow tendinopathy: a prospective, single-blind, randomised trial of autologous blood injections versus platelet-rich plasma injections. Br J Sports Med 2011; 45: 966–71.