Should fractures in massive intercalary bone allografts of the lower limb be treated with ORIF or with a new allograft?

BACKGROUND: Massive bone allografts have been used for limb salvage of bone tumor resections as an alternative to endoprostheses, although they have different outcomes and risks. There is no general consensus about when to use these alternatives, but when it is possible to save the native joints after the resection of a long bone tumor, intercalary allografts offer some advantages despite complications, such as fracture. The management and outcomes of this complication deserve more study. QUESTIONS/PURPOSES: The purposes of this study were to (1) analyze the fracture frequency in a group of patients treated with massive intercalary bone allografts of the femur and tibia; (2) compare the results of allografts treated with open reduction and internal fixation (ORIF) with those treated with resection and repeat allograft reconstruction; and (3) determine the likelihood that treatment of a fracture resulted in a healed intercalary reconstruction.
METHODS: We reviewed patients treated with intercalary bone allografts between 1991 and 2011. During this period, patients were generally treated with intercalary allografts when after tumor resection at least 1 cm of residual epiphysis remained to allow fixation of the osteotomy junction. To obtain a homogeneous group of patients, we excluded allograft-prosthesis composites and osteoarticular and hemicylindrical intercalary allografts from this study. We analyzed the fracture rate of 135 patients reconstructed with segmental intercalary bone allografts of the lower extremities (98 femurs and 37 tibias). In patients whose grafts fractured were treated either by internal fixation or a second allograft, ORIF generally was attempted but after early failures in femur fractures, these fractures were treated with a second allograft. Using a chart review, we ascertained the frequency of osseous union, complications, and reoperations after the treatment of fractured intercalary allografts. Followup was at a mean of 101 months (range, 24-260 months); of the original 135 patients, no patient was lost to followup.
RESULTS: At latest followup, 19 patients (14%) had an allograft fracture (16 femurs [16%] and three tibias [8%]). Six patients were treated with internal fixation and addition of autologous graft (three femurs and three tibias) and 13 patients were treated with a second intercalary allograft (13 femurs). The three patients with femoral allograft fractures treated with internal fixation and autologous grafts failed and were treated with a second allograft, whereas those patients with tibia allograft fractures treated by the same procedure healed without secondary complications. When we analyzed the 16 patients with a second intercalary allograft (13 as primary treatment of the fracture and three as secondary treatment of the fracture), five failed (31%) and were treated with resection of the allograft and reconstructed with an endoprosthesis (four patients) or an osteoarticular allograft (one patient).
CONCLUSIONS: Fractures of intercalary allografts of the tibia could successfully be treated with internal fixation and autologous iliac crest bone graft; however, this treatment failed when used for femur allograft fractures. Femoral fractures could be treated with resection and repeat allograft reconstruction, however, with a higher refracture frequency. The addition of a vascularized fibular graft in the second attempt should be considered. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.