Anterior Spinal Reconstruction With Structural Femoral Allograft After En Bloc Spinal Tumor Resection in the Thoracolumbar Spine: A Case Series With Median 7-Year Follow-Up

Background Structural femoral allografts possess favorable biomechanical properties and may serve as an effective and potentially less costly alternative to synthetic implants for anterior spinal column reconstruction. This study aims to describe the time to fusion and long-term outcomes of using fresh frozen femoral structural allografts for vertebral body reconstruction following en bloc spinal tumor resection. Methods This retrospective case series included patients who underwent en bloc vertebrectomy with anterior column reconstruction using fresh frozen femoral structural allografts between 1994 and 2019. Each allograft was prepared with a preinserted pedicle screw to allow connection to the posterior pedicle screw–rod construct. Demographic, oncological, and surgical data were collected. The primary outcome was graft fusion and time to fusion, assessed primarily using computed tomography. Results Fourteen patients were treated, with a mean age of 38 years (range 11–63 years). Nine patients had primary spinal tumors, and 5 patients had oligometastatic spinal metastases. Median follow-up was 78 months (range 24–324 months). An all-posterior approach was utilized in 13 of 14 patients. Iliac crest bone graft was used to pack the allograft in 12 patients, while cement was used in 2 patients. Mean time to fusion was 11 months (range 6–18 months). One patient developed rod breakage secondary to delayed union requiring revision posterior instrumentation and posterolateral bone grafting, with subsequent fusion achieved. One intraoperative femoral allograft fracture occurred during screw insertion prior to implantation and was successfully treated with cerclage fixation. Conclusions Structural femoral allografts represent a viable option for anterior spinal column reconstruction following en bloc spinal tumor resection. Posterior stabilization of the allograft using pedicle screws provides mechanical stability while avoiding the need for additional anterior instrumentation. Level of Evidence 4