Effect of Intramedullary Polymethylmethacrylate and Autogenous Cancellous Bone onHealing of Frozen Segmental Allografts

摘要

This study was designed to compare limb function, bone mineral density,periosteal callus, new bone, porosity, histology, and union of mid-diaphyseal segmental allografts of the femur stabilized with an interlocking nail (ILN) technique in a dog model. An in vivo study was performed to compare the effects of augmenting ILN fixation with the following: ILN alone (n), ILN plus intramedullary cement (nc), ILN plus intramedullary cement and autogenous cancellous bone applied to the periosteal surface of the host-allograft junction (ncp), ILN plus autogenous cancellous bone applied to the endosteal surface of the allograft (ne), ILN plus autogenous cancellous bone applied to the periosteal surface of the host-allograft junction (np), and ILN plus autogenous cancellous bone applied to the periosteal surface of the host-allograft junction and to the endosteal surface of the allograft (npe). Following allograft implantation, the dogs were evaluated by radiography, dual energy X-ray absorptiometry, and force plate gait analysis from 0 to 24 weeks. Six months after allograft implantation, the dogs were euthanatized and the femora processed for analysis. There were no differences between treatments for limb function or bone mineral density. Callus area 4 weeks after surgery was greater along the lateral and cranial surfaces for treatments receiving periosteal cancellous bone (P<0.05). This was also evident along the caudal surface at 24 weeks (P<0.05). New bone within the allograft segment did not differ between treatments and was reduced compared to the host-allograft junctions (P<0.05). Histologic scores were greatest with treatments 'ncp' and npe', listed above (P<0.05).