REGENERATION OF DEFECTS IN ARTICULAR-CARTILAGE WITH CALLUS AND CORTICAL BONE-GRAFTS - AN EXPERIMENTAL-STUDY

Cartilage regeneration was studied in an experiment in rats. A standar dised full-thickness articular cartilage defect was created and autoge nous 12-day-old callus or cortical bone graft was transplanted into it , or the defect was left empty. The follow up periods were three, six, 12, and 24 weeks, and each subgroup Consisted of five animals. A tota l of 60 animals were operated on. From six weeks onwards hyaline-like cartilaginous tissue had started to develop at the edges of the defect in all three groups. In the middle section of the hole, however, the picture was different; at 24 weeks none of the specimens in the defect group, two of the five in the callus graft group, and all five in the bone graft group had developed full-thickness, hyaline-like cartilagi nous regeneration. The hyaline-like cartilaginous tissue in the medial segment was hypocellular when analysed by histomorphometry. On scanni ng electron microscopy the surface of the reparative tissue looked fib rillated in all specimens from the three groups.