Does platelet-rich plasma deserve a role in the treatment of tendinopathy?

Although tendinopathies constitute a heterogeneous group of conditions, they are often treated by similar combinations of local and systemic symptomatic interventions. The vast number of causes, pathophysiological mechanisms, and histological changes that characterizes tendinopathies may explain that the standard treatment fails in some patients. Platelet-rich plasma (PRP), which contains a host of soluble mediators including growth factors, has been suggested as a second-line treatment for refractory tendinopathy, with the goal of expediting tendon healing or remodeling. Here, we report a systematic literature review of basic research data from humans and animals that support the clinical use of PRP in tendinopathies and of clinical studies in the most common tendinopathies (elbow, knee, shoulder, and Achilles tendon). Our objective is to clarify the role for this new injectable treatment, which is garnering increasing attention. The level of evidence remains low, as few well-designed randomized controlled trials have been published. The available scientific evidence does not warrant the use of PRP for the first-line treatment of tendinopathy. PRP therapy may deserve consideration in specific tendinopathy subtypes, after failure of ultrasound-guided corticosteroid injections. Nevertheless, further studies are needed to define these potential indications and the optimal treatment protocols. A key point is that the complexity of the tendon healing process cannot be replicated simply by injecting a subset of growth factors, whose effects may occur in opposite directions over time. Topics not discussed in this review are the regulatory framework for PRP therapy, PRP nomenclature, and precautions for use, which are described in a previous article (Does platelet-rich plasma have a role in the treatment of osteoarthritis, Ornetti P, et al. [1]).