Rabbit articular cartilage defects treated with cultured costal chondrocytes (preliminary report).

An attempt to repair articular cartilage defects by costal chondrocytes transplantation was made. A full-thickness defect in the rabbit's femoral patellar groove was artificially made. Cultured costal cartilage chondrocytes were then transplanted into the defects and covered with periosteal flaps. Empty defects were used as the control group. Animals were divided into two groups (five rabbits each). They were examined after four and twelve weeks from the day of transplantation, respectively. The reparative tissue was evaluated by macroscopic and histological examinations. The reparative tissues in defects with transplanted chondrocytes had an hyaline-like cartilage appearance and were firmly attached to the surrounding normal cartilage. No trace of newly formed bone was detected. The reparative tissues found in defects that were left empty had a fibrous character. They were loosely connected to the surrounding cartilage and were more compliant than tissues from transplanted defects. Considering these initial findings, the ease of surgical procedures during the harvesting of the costal cartilage and few interventions into the joint make the costal cartilage a promising source of chondrocytes for transplantation. However, this needs to be confirmed on a larger scale over a longer period of time.