Autoclaved autograft bone combined with vascularized bone and bone marrow

Abstract

In this study, the authors investigated enhancing the results of autoclaved autograft bone by combining it with a vascularized bone graft and supplementing it with autogenous bone marrow for replacement of a 2-cm tibial defect in the rabbit model. The study was divided into 4 groups. Group I consisted of autoclaved autograft bone only; Group II, autoclaved autograft bone and vascularized bone graft; Group III, autoclaved autograft bone and autogenous bone marrow; and Group IV, autoclaved bone and autogenous bone marrow and vascularized bone graft. The vascularized bone graft was provided by the ipsilateral fibula, pedicled on the peroneal vessels, and transposed to sit alongside the autoclaved bone. In Group I, all grafts had nonunion at 16 weeks. In Group II, new bone formation was seen at the proximal and distal site of the autoclaved bone, host bone, and vascularized fibular graft junction as early as 2 weeks, and bony union occurred at the 16th week. The autogenous bone marrow-supplemented groups (III and IV) had new bone formation along the entire length of the autoclaved bone. Bony union at the proximal and distal junction was seen as early as 4 weeks, extending to the entire autoclaved bone by the eight week (98% of the cases with 1 case of infection). Histologic examination showed revascularization and capillary ingrowth into the autoclaved bone at 16 weeks, with a significantly improved torsional stiffness when compared with the groups without autogenous bone marrow supplementation. The addition of vascularized bone graft resulted in an improved union rate as compared with the autoclaved bone alone. Autogenous bone marrow supplementation, in addition to the vascularized bone graft, resulted in rapid new bone formation all around the autoclaved bone, early revascularization and incorporation of the autoclaved bone, and a significantly improved torsional stiffness of the reconstruction.