Influence of inflammation on tendon healing and the use of platelet-rich plasma

Abstract

Tendon injuries may result from acute trauma or chronic overuse and typically present with pain, inflammation, weakness, and stiffness. These conditions often fail to resolve with rest alone and usually require a multimodal treatment approach. Among the available strategies, plateletrich plasma (PRP) and ultrasound-guided electrolysis (USGET) have shown significant potential to enhance the body's intrinsic healing mechanisms. However, the efficacy of PRP depends critically on the preparation method and the specific inflammatory context in which it is applied. Acute inflammation is a rapid and controlled response that initiates the healing cascade. In contrast, persistent, unresolved inflammation leads to chronic inflammation, fibrosis, and degenerative changes, affecting biomechanical properties and adjacent tissues, as seen in chronic tendinopathies.

This review summarizes the cellular and molecular mechanisms underlying tendon repair, with a focus on the spatiotemporal interplay of inflammatory mediators and growth factors during acute and chronic inflammation. We also examine the mechanistic rationale and clinical evidence for PRP and USGET, alone and in combination, across different tendinopathies. Although no consensus exists regarding the superiority of either PRP or USGET as stand-alone treatments, we propose that, in chronic tendinopathies, physical stimulation of fibrotic tissue by USGET, followed by PRP infiltration and eccentric exercises, may reactivate the healing cascade and support each phase of the repair process. This approach has shown promising results in refractory tendon injuries, offering distinct advantages over conservative treatments. Emerging clinical data suggest that this integrative approach provides advantages over conservative therapies in refractory tendon injuries.