Abstract
OBJECTIVES: Pelvic bone tumor resection and reconstruction present significant challenges due to complex anatomy and weight-bearing demands. 3D-printed hemipelvic prostheses, incorporating customized osteotomy guides and porous structures, offer a promising solution for enhancing osseointegration. This study evaluates the long-term outcomes of 3D-printed custom hemipelvic reconstruction with a focus on the integration of auxetic biomaterials with a negative Poisson's ratio to optimize mechanical properties. METHODS: A retrospective analysis was conducted on 12 patients with primary pelvic malignancies who underwent reconstruction using 3D-printed hemipelvic prostheses between January 2018 and May 2023. Follow-up duration was 48 months (range, 29-64 months) Oncological, functional, surgical, pain control, and radiographic outcomes were assessed. RESULTS: At the latest follow-up, 8 patients (66.7%) were disease-free, 3 (25%) had disease progression, and 1 (8.3%) died from metastatic complications. Functional outcomes improved significantly, with the MSTS-93 score increasing from 15 (range, 12-17) to 26 (range, 21-29). Pain scores decreased from 5 (range, 4-7) to 1 (range, 0-2). The median surgical duration was 270 min (range, 150-560 min), with intraoperative blood loss averaging 3200 mL (range, 1900-6300 mL). Complications included poor wound healing in 2 patients (16.7%), managed with VAC drainage. No mechanical failures, loosening, or fractures occurred. Accurate osteotomy, prosthesis implantation, and screw fixation were achieved. Successful osseointegration was observed in all cases, with no signs of bone absorption or osteolysis. CONCLUSIONS: 3D-printed custom hemipelvic prostheses with auxetic biomaterials offer an effective solution for pelvic reconstruction, providing promising oncological, functional, and radiographic outcomes. These findings support the use of 3D printing in complex pelvic defect reconstruction, optimizing both osteointegration and mechanical strength.