[Experimental study of vascularized fibular grafting including the epiphyseal growth plate--autogenous orthotopic grafting].

Advancements of microsurgery opened up a new horizon in various facets of surgery. Vascularized bone grafting is one of them and promised viable bone grafting with superb results. Whether this bone grafting along with the epiphyseal growth plate yields continuous bone growth is a matter of great concern and the purpose of the present study. Thirty-nine puppies were used for the experiment, and they were divided into two groups. The proximal portion of the fibula was resected with the popliteal artery and vein including their branches to the epiphysis and the metaphysis, and then, the fibula was returned to the original place and fixed with two Kirschner wires. In group 1, the artery and vein were anastomosed with 10-0 Nylon sutures under operative microscope. In group 2, the bone was treated in a same fashion, but without vascular anastomosis. The roentgenological and histopathological changes were sequentially studied in the both groups. Results were summarized as follows: In group 1, 13 dogs were followed until the epiphyseal closure completed. In two dogs, the treated fibula was of equal length with the non-treated opposite fibula, whereas in five dogs there was slight hypogrowth (average 1.8 mm) and in six dogs there was slight overgrowth (average 2.2 mm). Otherwise, The roentgenological appearance was essentially normal. There was no significant difference in the histopathology of the epiphyseal plates in the treated and the non-treated fibulas. In group 2, all the treated fibulas failed to show epiphyseal growth. Roentgenologically destruction and absorption appeared as early as in the first and second week postoperatively, followed by a fracture line through the metaphysis with displacement and nearly complete absorption of the grafted bone. Histopathological findings consisted of early destruction of the growth plate and early necrosis of the bone marrow as well as the bone trabeculae of the epiphysis, metaphysis and diaphysis. Some reparative new bone formation was noted in the grafted area. In conclusion, the results of the experiment showed the possibility of normal bone growth when a bone is grafted with its epiphyseal growth plate provided the vascular supply to them is reconstructed.