[The revascularisation of fresh homologous bone grafts in the diaphysis of long bones in dogs (author's transl)].

In two series each 5 X 2 grown up mongrel dogs we studied the healing process of fresh concellous and cortical homografts in a defect made in the diaphysis of the radius bone. The experiments cover microangiographical and histological weekly control in the first 6 weeks after transplantation. The results demonstrate that the fresh concellous homografts have a good revascularisation and produce early new bone in the first week. The revascularisation of the cortical grafts is delayed. The immune reaction, which begins after two weeks, is in concellous bone graft more vigorous than in the cortical graft. The reaction leads to vascular disruption prior to the degenerative and necrotic changes of the tissue cells in the grafts including the new bone formation. After overcoming the immune reaction the 2nd or the so called inductive phase of new bone formation starts. The integration of cortical grafts in the host bone is much slower than in concellous bone graft. The vigorous immune reaction followed by the avascular interval in the concellous homografts between the second and third week must be considered as a dangerous critical phase when using homografts in the clinic. Because of the less cell concentration in the cortical homografts there is less immune reaction. Revascularisation in cortical homografts is slow and consequently there is a delayed incorporation of the grafts in the clinical use.