[Experimental study of vascular bundle transplantation to femoral head of young mongrel dog (author's transl)].

This paper describes an experimental study on vascular bundle transplantation into the femoral head of puppies before epiphyseal arrest. Sixty-seven young mongrel dogs, about 3 months of age, were used in this study. Necrotized femoral heads were made by interruption of blood supply to the femoral head, extramedullary and intermedullary. The transplantation of a vascular bundle was performed on intact and necrotized femoral heads. One month after the interruption of blood supply, deformity, atrophy and cystic formation of the head, and wide radiolucent shadow in the metaphysis were noted. Observation over nine months revealed flattening of the femoral head, shortening of the femoral neck and disappearance of the femoral head in severe cases. In the transplantation to intact femoral heads, transplanted vascular bundles maintained patency and anastomosed with preexisting vessels. Neither hypertrophy of the head nor distinctive pathological change was seen in the transplanted head or in the control side. In the transplantation to necrotized femoral heads, proliferation of new blood vessels was seen in the whole head. One month after the transplantation, new bone formation was active with proliferation of capillaries. Two months after the transplantation, dense cancellous bone or lamellar bone was made within the head, which showed atrophy in four months after the surgery and bone marrow was restored. In the case of severe changes in the epiphyseal cartilage, deformity of the femoral head and shortening of the neck were noted although better restoration was obtained than in the control.