Using 3D Printing Sacral Endoprosthesis for Spinopelvic Reconstruction

Abstract

Primary sacral tumor is rare, for which surgical resection is the cornerstone of therapy [1, 2]. For primary sacral malignancies involving the upper sacrum, the main treatment is total en bloc sacrectomy (TES). Although the functional outcome of TES-treated patients without spinopelvic reconstruction has been reported as acceptable [3], the bone defect resulting from TES which leads to the discontinuity between spine and pelvis often requires reconstruction because of the facilitation for early mobilization which precludes the complications in patients who are bedridden for a long time [4]. According to the classification proposed by Bederman et al., the reconstruction methods after TES can be categorized into three types: spinal pelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and anterior spinal column fixation (ASCF) [5]. It was suggested that a combined reconstruction including ASCF would be the optimal reconstructive method after TES [5]. However, the combined reconstruction including ASCF conceivably has an increased risk of prolonged surgical time and massive intraoperative hemorrhage, which would impair the safety of the procedure. To address this problem, several unconventional reconstruction methods aiming at synthesizing SPF/SPF+PPRF and ASCF, such as reimplantation of extra-corporeally irradiated sacrum and endoprosthesis replacement, had been reported [6, 7], which, however, could hardly show advantages over another due to the limited number of cases. In general, the standardized reconstructive method for TES-treated patients remains controversial.