Histologic evaluation of the repair process of chondral and osteochondral lesions in a rabbit model

Healing of partial and osteochondral surgical cartilaginous lesions to the rabbit femur was studied histologically to determine healing time and quali ty of the repaired/regenerated tissue, so as to construct an experimental i n vivo model for the evaluation of medical and/or surgical therapies, which so far have not ensured complete resolution of the cartilaginous defects. In eighteen New Zealand rabbits, an osteochondral lesion (2.5 x 2 mm) was d rilled in the right femoral medial condyle by lateral cutaneous incision an d arthrotomy of each knee was performed, while, a chondral lesion (1.25+/-0 .2 x 0.8+/-0.2 mm) was created in the left femoral medial condyle of each r abbit. Results showed no healing of the chondral defect and abnormal bony g rowth beyond the articular profile with a fibrous coating, even at 12 weeks in osteochondral lesion.