Platelet-Rich Plasma (PRP) Injection in Achilles Tendinopathy: A Literature Review

Abstract

Achilles tendinopathy is a chronic musculoskeletal condition characterized by pain, stiffness, and reduced function of the Achilles tendon, particularly during weight-bearing activities. It affects approximately 6% of the general population and up to 50% of competitive endurance runners during their lifetime, potentially impairing daily activities and athletic performance. Achilles tendinopathy is regarded as a degenerative disorder resulting from failure of the tendon’s healing response to repetitive mechanical loading, rather than an acute inflammatory process. This condition is associated with collagen disorganization, extracellular matrix alterations, neovascularization, and abnormal sensory nerve ingrowth. Platelet-rich plasma (PRP) has emerged as a biological therapeutic option for chronic Achilles tendinopathy, especially in patients unresponsive to standard conservative management. PRP acts through the release of growth factors, including platelet-derived growth factor, transforming growth factor-beta, and vascular endothelial growth factor, which promote cell proliferation, angiogenesis, and tendon remodeling. PRP is commonly administered in volumes of 3–6 mL per injection, either as a single injection or as serial injections at 2–3-week intervals. However, clinical evidence remains limited due to heterogeneity in PRP preparation and injection protocols, highlighting the need for further well-designed, standardized studies to establish clearer clinical recommendations.