Extracorporeal shock waves in articular cartilage defects in the rats

Thirty adult Sprague–Dawley rats were used to assess the nature of healing tissues in hyaline cartilage defects and to compare the healing in defects treated with shock waves, with those in defects without treatment. A 2 × 2 mm cartilage defect with exposed cancellous bone was created in a nonweight-bearing area of each medial femoral condyle. Each right knee defect was received extracorporeal shock waves (Swiss Dolorclast) of 500 impulses in 5 min at 2 bar (comparative to 0.09 mJ/mm²), and the left knee defects were assigned as controls. The rat groups were sacrificed at 6 and 12 weeks postsurgery. Sections from each knee were stained with hematoxylin-eosin to analyze synovial adhesion, synovial thickness, bone maturation, and chondroid metaplasia and with masson trichrome to analyze collagen fiber intensity. There was not a significant difference found between the study and control groups (P > 0.05). Extracorporeal shock waves did not effect healing of the chondral defects.