Deciphering the function and mechanism of extracorporeal shock wave therapy in knee osteoarthritis (Review).

Knee osteoarthritis (KOA) is a chronic, disabling disease with multiple etiologies and a complex pathophysiology. Conservative treatment is the cornerstone of KOA management, and when it proves insufficient, extracorporeal shock wave therapy (ESWT) has emerged as a practical non‑invasive alternative. The present narrative review systematically summarizes current preclinical and clinical evidence on ESWT for KOA through a structured literature search, aiming to integrate its therapeutic effects and identify knowledge gaps. Accumulating evidence indicates that ESWT can slow KOA progression through multiple biological pathways, encompassing anti‑inflammatory, anti‑apoptotic, pro‑proliferative and cartilage‑protective effects, while also relieving pain and improving function clinically. Summarizing the available data, this review finds that ESWT exhibits a favorable safety profile for articular tissues and disease‑modifying potential in preclinical models, although treatment outcomes depend critically on energy flux density and protocol selection. In human studies, the current evidence primarily supports symptomatic relief, including pain reduction and functional improvement; high‑quality trials with structural endpoints to verify cartilage regeneration or joint space preservation remain scarce. Given its non‑invasive nature, safety and growing clinical support, ESWT merits consideration as an adjunctive therapy. However, heterogeneity in treatment parameters and limited long‑term data preclude standardized guidelines. Despite these limitations, ESWT remains a promising adjunctive therapy for patients who are unresponsive to conventional conservative treatments. Future research should prioritize parameter optimization, extended follow‑up and translational studies to bridge the gap between preclinical structural findings and clinical application. Addressing these gaps will strengthen the therapeutic role and scientific foundation of ESWT.