Transplantation of tissue-engineered osteochondral plug using cultured chondrocytes and interconnected porous calcium hydroxyapatite ceramic cylindrical plugs to treat osteochondral defects in a rabbit model.

The purpose of this study was to evaluate the macroscopic and histological results of transplanting a tissue-engineered composite plug made of tissue-engineered cartilage and interconnected porous calcium hydroxyapatite ceramics (IP-CHA) with a very high porosity of 94.9% to treat osteochondral defects. Twelve 12-week-old male Japanese white rabbits were used. Fresh articular cartilage slices were taken, and isolated chondrocytes (2 x 10(6) cells) were embedded in atelocollagen gel. They were seeded on the top of IP-CHA plugs and cultured for 2 weeks. These tissue-engineered composite plugs were transplanted into the osteochondral defects in the patellar grooves (the experimental group). In the control group, the defects were treated with composite plugs without chondroytes. Twelve weeks after transplantation in the experimental group, the defects were repaired with cartilage-like tissue with good subchondral bone formation histologically. Histological scores in the experimental group were significantly better than those in the control group. This study clearly showed the defects that had been treated with tissue-engineered composite plugs.