BONE DEFECT REPAIR WITH TISSUE-ENGINEERED CARTILAGE

We tested the efficacy of a new approach for the tissue-engineered gro wth of cartilage developed in our laboratory in repairing surgically c reated bone defects in the craniums of rats. Large cranial defects wer e created bilaterally in the frontoparietotemporal bones of athymic nu de rats (n = 10). There was gross evidence of new cartilage in 8 of 10 experimental defects that had been filled with a synthetic biocompati ble, biodegradable polymer template that had been seeded in vitro with freshly isolated chondrocytes. The control defects, filled with eithe r nothing at all or a polymer template without chondrocytes, showed no evidence of cartilaginous repair (0 of 10). Statistical analysis usin g McNemar's test with pooled samples showed significant differences be tween the two groups (p<0.05). Prior reports concerning the biologic r epair of bony defects involved stimulation of adjacent mesenchymal tis sue and resulted in ingrowth of new bone. To our knowledge, this is th e first report of structural cartilaginous repair of a bony defect wit h matrix secreted by implanted chondrocytes.