Platelet-Rich Plasma Therapy in Treating Tendon Injuries of the Hand: A Narrative Review.

Platelet-rich plasma (PRP) therapy has emerged as a biologically based approach to enhance tendon healing and functional recovery in hand and other musculoskeletal injuries. PRP is an autologous concentrate of platelets and growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), insulin-like growth factor (IGF), and vascular endothelial growth factor (VEGF), which modulate inflammation, stimulate tenocyte proliferation, promote collagen synthesis, and support angiogenesis. Preclinical studies demonstrate that PRP improves extracellular matrix remodeling, collagen fiber alignment, and biomechanical strength in injured tendons, with effects influenced by PRP formulation, leukocyte content, activation method, and timing of application. Clinical evidence in hand tendon injuries-particularly flexor tendon repair, chronic tendinopathies, and stenosing tenosynovitis-suggests that PRP is generally safe and may enhance tendon morphology, range of motion, pain relief, and return to function. However, results are heterogeneous, with some randomized trials showing limited short-term functional improvements compared to conventional treatments such as corticosteroids, hyaluronic acid, or percutaneous needle tenotomy. The variability in outcomes reflects differences in PRP preparation, injection protocols, injury chronicity, and study design. Beyond the hand, PRP has been applied to rotator cuff, lateral epicondylitis, plantar fasciitis, ligament injuries, and spinal surgery, with mixed results and some evidence of tissue-specific limitations. Current challenges include standardizing PRP formulations, optimizing dosing and delivery, and identifying patient- and injury-specific factors influencing response. Future research should prioritize multicenter, well-powered randomized trials with uniform outcome measures, long-term follow-up, robust safety monitoring, and exploration of combination therapies to clarify the therapeutic role of PRP and support evidence-based integration into clinical practice.