[Irradiation of bone homografts. Their use following tumor resection. Apropos of 4 cases].

Since 1978 gamma irradiation has been used for sterilization of bone allografts. The radiation source used was Co 60 (2.5 to 3 megarads). Which was applied at the Atomic Centre of Saclay. The technique of sterilization is absolutely reliable at relatively low cost. It allows pieces of bone from cadavers to be harvested several hours after death, without special aseptic precautions. It appears to diminish antigenicity of the graft very little and incorporation is perhaps slowed down. The grafts did not become radioactive. The graft is carefully packed and frozen as soon as it is taken from the cadaver. Freezing is continued during the irradiation process and the graft may then be stored for several months. This technique was used for reconstruction after tumor resection twice in the knee, once in the pelvis and once in the fibula. There was no postoperative infection. Scintigraphy showed satisfactory incorporation. In one case of replacement of the femoral condyle the cartilage of the graft was replaced by the intact articular cartilage of the patient. Later, this articular cartilage was shown to be necrotic and a total prosthesis was inserted. The fibular graft was secondarily complicated by a fracture. Sterilization using irradiation makes bone harvesting in cadavers easier and allows bone banks to be established. It should lead to more extensive use of allograft bone.