Auto-destruction of the articular cartilage and free radical mediators

The effect of static compression on the release of superoxide (SO) and nitric oxide (NO) from cartilage obtained from rabbit knee joints with tissue defects was studied. The rabbits were divided into two groups: (1) those that had 5 mm diameter full chondral defects (defect group) and (2) those in which chondral defects were filled with autogenous perichondrial grafts (grafted group). Histologically, cartilage was regenerated in the grafted group 3 weeks after the operation, although only a fibrous tissue filled the defects in the defect group even 16 weeks after the operation. A static pressure of 5 kg for 10 minutes applied to the cartilage chips obtained from the area surrounding the defects released significant amounts of SO and NO into the medium. Maximum increases were observed in the defect group 3 weeks after the operation.