Incorporation of nonviable bone grafts. Autoclaved autogeneic and frozen allogeneic bone grafts compared in the rabbit

Abstract

In 14 adult rabbits the middle third of the ulna was resected bilaterally followed by reimplantation of resected bone after autoclaving on one side and transplantation of allogeneic bone on the other. In 7 animals the bilateral implants were supplemented with allogeneic bone matrix. The reconstructions were studied in vivo by serial radiography, scintigraphy, and bone mineral determination. The animals were killed at 16 weeks, and the ulnar reconstructions further studied by high resolution radiography, 45Ca autoradiography, and histology. In both types of nonsupplemented reconstructions, new bone formation was poor; nonunion occurred in three out of seven autoclaved reimplants and in five out of seven allogeneic transplants. Supplemented with allogeneic bone matrix, both types of reconstructions exhibited abundant new bone formation and complete incorporation of all implants. Enhancement of new bone formation is probably more important than the type of nonviable bone graft chosen for reconstruction of large skeletal defects.