Ultrastructural changes of articular cartilage following joint immobilization with the Ilizarov apparatus.

To study the effects of immobilization upon the ultrastructure and surface contour of articular cartilage, the knee joints of adult dogs were immobilized with the Ilizarov apparatus for different lengths of time. Following immobilization, half of the dogs were permitted unrestrained joint motion, also for different lengths of time. Using light transmission and scanning electron microscopy it was observed that the degree of degenerative and destructive cartilage changes increased with greater immobilization. With the re-mobilization group, it was learned that the longer the period of mobilization following immobilization, the greater the reparative processes.