Intra-articular loose bodies regarded as organ cultures in vivo.

A study of the changes which occur in the intra-articular loose bodies which contain hyaline cartilage, showed the chondrocytes to be very versatile. To effect the transformation of a fractured portion of the articular surface from an angular to a rounded body, peripheral chondrocytes lyse the surrounding glycans and revert to fibroblasts before proliferating and forming fibrocartilage. The central chondrocytes show a wide variety of changes which may mask the original structure of the hyaline cartilage. Remodelling can occur by the formation of osteoclasts. Analogies are drawn between the behaviour of chondrocytes in culture and in some pathologic processes.