Scanty integration of osteochondral allografts cryopreserved at low temperatures with dimethyl sulfoxide

To compare the integration of osteochondral allografts cryopreserved at different temperatures and different concentrations of dimethyl sulfoxide in an in vivo sheep animal model. Thirty-six adult sheep were randomly allocated to 6 groups of allograft osteochondral transplantation. Six osteochondral cylinders were stored for 6 weeks at -80A degrees C; 6 at -80A degrees C with 10% dimethyl sulfoxide (DMSO); 6 at -80A degrees C with 10% DMSO for 90 min; 6 at -186A degrees C; 6 at -186A degrees C with 10% DMSO; 6 at -186A degrees C for 90 min. After transplantation, all animals were euthanized at 6 months. Harvested specimens underwent gross morphologic and histologic evaluation. We found no statistically significant differences when comparing the gross cartilage morphology and histopathologic scores of each group. The Mankin and OARSI scores and the modified Wakitani and OARSI scores showed a good correlation grade. The Mankin and modified Wakitani scores showed a fair correlation grade. The cryopreservation protocols adopted in the present study provided scanty integration in an in vivo sheep model of osteochondral allograft transplantation. Therefore, their use in the clinical practice is discouraged.