Revascularization and new bone formation in heat-treated bone grafts

Human immunodeficiency virus (HIV) infection is one of the possible serious complications associated with bone allografts. In order to prevent infecti on, grafted bone is sterilized by various treatments. Heat treatment has at tracted attention as a simple and practical method. We carried out a histol ogical study of the influence of heat treatment on autogenic bone grafts. T o eliminate the problem of antigenicity of grafted bone, we used autografts , not allografts. Three types of heat-treated autografts were employed: hea t-treated at 60 degrees C for 30 min, at 80 degrees C for 10 min, and at 10 0 degrees C for 5 min; as a control, fresh autografts were replaced in the rabbits' ilium. One, 2, 4 and 8 weeks after grafting, we performed microang iography and prepared two types of samples: transparent and haematoxylin-eo sin (H&E) stained. Then, using an image analyzer, we quantitatively measure d revascularization and new bone formation in the grafted bone. The grafts heat-treated at 60 degrees C showed early and good revascularization and ne w bone formation, from 1 to 8 weeks. The grafts heat-treated at 80 degrees C showed relatively good revascularization and new bone formation. However, the grafts heat-treated at 100 degrees C showed unsatisfactory revasculari zation and bone formation, less than 40% of control 8 weeks after grafting. Therefore, heat treatment at 60-80 degrees C does not seriously affect rev ascularization and new bone formation.