Abstract
ABSTRACT: Introduction: Osteochondral lesions (OCL) are a key pathological feature in osteoarthritis, necessitating effective treatments that target both cartilage and subchondral bone. Extracorporeal shock wave (ESW) therapy, a noninvasive modality, shows promise but its holistic effects on the osteochondral unit require further elucidation. Objectives: This study aimed to investigate the therapeutic effects of ESW on cartilage repair and subchondral bone remodeling in a rat OCL model. Methods: Thirty-six Sprague-Dawley rats were randomized into Control, OCL (monosodium iodoacetate-induced), and OCL+ESW groups. The OCL+ESW group received weekly ESW treatment (1.0 bar, 800 impulses, 6 Hz). Functional recovery was assessed longitudinally via gait analysis (CatWalk). At end point, knee joints were analyzed using micro-computed tomography and histological staining (Safranin O-Fast Green, Toluidine Blue). Results: Micro-computed tomography revealed that ESW significantly ameliorated monosodium iodoacetate-induced subchondral bone deterioration, restoring bone mineral density, bone volume fraction (BV/TV), and trabecular number (Tb.N) toward normal levels. Gait analysis demonstrated significant functional improvement in the OCL+ESW group from week 4, with parameters like maximum contact area and intensity normalizing by week 8. Histology confirmed marked preservation of cartilage integrity, surface smoothness, and proteoglycan content in ESW-treated animals compared to the degenerative OCL group. Conclusions: ESW therapy effectively mitigates cartilage degeneration and promotes subchondral bone remodeling, leading to significant functional recovery. Our findings underscore the translational potential of ESW as a noninvasive treatment strategy for osteochondral defects and early osteoarthritis. The translational potential of this article: This preclinical study provides robust evidence supporting ESW therapy as a viable, noninvasive treatment for osteochondral lesions. By demonstrating simultaneous efficacy on both cartilage and bone—the critical components of the osteochondral unit—it bridges the gap between basic research and clinical application, paving the way for ESW to become a first-line, disease-modifying therapy for osteoarthritis, potentially reducing the need for surgical intervention.