Platelet Rich Plasma for Treating Chronic Tendinopathy

Tendinopathy is a major problem in medicine and sports traumatology. It is due, inter alia, to mechanical overload. It remains a challenge for the medical world to the extent that its frequent resistance to conventional treatments never promises the patient a favourable response following therapeutic management. The development of platelet-rich plasma (PRP) is a new hope when therapeutic treatments such as NSAIDs, corticosteroid injections, eccentric rehabilitation, shock waves, etc. have shown their limits. Furthermore, since January 2011, it is no longer included on the list of doping substances (http://www.wada-ama.org/).
Indeed, platelets contain various growth factors (PDGF, TGF-β, FGF, VEGF, HGF, IGF-1) which participate to the tendon healing process. PRP is obtained by centrifugation of autologous blood to obtain a platelet concentration greater than that of the blood, which varies according to the production method. PRP also contains a variable amount of lymphocytes and erythrocytes that can have a detrimental effect on wound healing. Currently, there is no formal consensus regarding the production method or the biological composition of PRP.
Many laboratory studies (in vitro and/or on animal) emphasize the acceleration of the healing tendon process after injection of PRP, each growth factor exerting a specific action during healing. PRP would cause the proliferation, migration and differentiation of cells derived from circulation, improving the initial phase of the tendon healing. This anabolic process initiates the type I collagen synthesis.
Although currently the effectiveness of PRP on tendon healing in vitro or in animals seems to be confirmed, clinical studies are currently still controversial. In addition, there is still only a limited number of randomized and controlled studies reviewing PRP for treating tendinopathy. However, it seems that PRP can be efficient to treat lateral epicondylitis, patellar tendinopathies and plantar fasciitis, even if the level of proofs remains low. Up to now there is not enough proofs concerning the use of PRP to treat rotator cuff or Achilles tendinopathies. More randomized, controlled and blinded studies remain needed.
In conclusion, experimentally, PRP, through the local release of various growth factors stimulates tendon healing. This therapy could optimize the healing of pathological human tendons. PRP should be analysed to see whether it improves tendon healing in both humans and animals through other randomized controlled trials.