Studies on the repair tissue of injured articular cartilage--biochemical and biomechanical properties.

The repair tissue of the articular cartilage of a rabbit was investigated biochemically and biomechanically. An analysis of the proteoglycan demonstrated the synthesis of heavy proteoglycan component as in hyaline cartilage, but its average size was slightly smaller than normal hyaline cartilage. The collagen changed its molecular type from type I to type II at the surface of the repair tissue simultaneously up to 7 weeks after the operation. The lack of normal mucoelasticity was found in the repair tissue by the static compression test, and this may be related to the abnormalities of the proteoglycan.