INCORPORATION OF CHEMICALLY-MODIFIED AND RADIATION-STERILIZED CANCELLOUS BONE ALLOGRAFTS

The effect of lipid extraction, partial decalcification, iodoacetate t reatment and glutaraldehyde (GA) cross-linking on incorporation of rad iation-sterilized cancellous bone allografts was compared to unmodifie d radiation-sterilized cancellous bone allografts and autogenous cance llous bone grafts in a cortical defect model in sheep tibia. Incorpora tion of the grafts was compared radiographically and histologically 56 days after implantation. The quantity and depth of extension of fluor escent label into the graft were evaluated from photomicrographs. GA c ross-linked allografts were more poorly incorporated and had the least penetration of tetracycline-labelled bone. All other allografts were incorporated similarly to the autografts except that tetracycline-labe lled bone was present to a greater depth in the autografts. The minima l differences between allografts and autografts may be explained by a reduction of the immunogenicity of all allografts by freezing and by r adiation sterilization. GA cross-linking prevented resorption of bone. Ingrowth may have been inhibited by residual GA.