Devitalized Autograft Associated with the Vascularized Fibula Graft: Irradiation versus Freezing Methods

Background Among the alternatives for the management of malignant bone tumors is the “devitalized autograft associated with vascularized fibula graft.” The devitalization process is achieved by pasteurization, irradiation, or freezing. The combination of these grafts has been broadly researched for more than 25 years. However, there is no research currently published comparing the various methods or their respective outcomes. Methods A retrospective study was compiled of 26 devitalized autografts associated with vascularized fibula performed to limb salvage of malignant bone tumors. They were divided into two groups according to the devitalization method: either freezing (12 procedures) or irradiation (14 procedures). Clinical, radiographic, and scintigraphic results were assessed at least 24 months after surgery. Results The union rates reached 83.3% in the freezing group and 92.8% in the irradiated group but did not express different outcomes. Scintigraphic viability was observed in all the grafts that achieved radiographic union (Mann–Whitney U-test: p = 0.005). Three patients had nonunion, with only one having no viability in the scintigraphy (Mann–Whitney U-test: p = 0.001). There was no malignant recurrence in the autograft, only in surrounding soft tissues. Local recurrence was statistically higher in larger tumors (Mann–Whitney U-test: p = 0.025). Conclusion Both groups presented similar union rates and are considered safe to devitalize bone graft despite different outcomes observed. The survivor rates observed could be limited by the existence of the techniques.

Bony Hypertrophy in Vascularized Fibular Grafts

Background: Vascularized fibula graft (VFG) transfer is an established method of repairing large skeletal defects resulting from trauma, tumor resection, or infection. It obviates the process of creeping substitution that conventional bone grafts undergo and therefore exhibits better healing and improved strength. The aim of this study is to evaluate hypertrophy in VFG. Methods: We retrospectively reviewed patients undergoing VFG and studied immediate and late postoperative radiographs. Orthogonal views were measured for width of graft cortex and intramedullary canal, as well as adjacent recipient bone. Changes were measured for total cross sectional area, cortical area, intramedullary area, and graft width. Results: Thirty patients were included in the analysis, with recipient sites including 3 forearm, 4 humerus, 12 tibia, and 11 femur. Mean follow-up was 7.6 years (0.5-24.9 years). Patients’ mean age was 31 (16-59 years). Average hypertrophy was 254% in early postoperative period and 340% in the late postoperative period. There was rapid graft hypertrophy in early postoperative period that plateaued with time. The width of the graft increased over time but didn’t exceed the width of the adjacent recipient bone. In the later postoperative period, the size of graft intramedullary canal increased. Upper and lower extremity grafts showed similar hypertrophy. Conclusions: Using VFG to treat large skeletal defects is an attractive option in part due to the graft’s ability to hypertrophy. We describe an early period of periosteal hypertrophy, followed by endosteal hypertrophy. These processes have relevance to function, mechanical strength, and surgical decision-making.