Personalized 3D-printed guide in malignant bone tumor resection and following reconstruction-17 cases in pelvic and extremities

Introduction: Customized accurate tumor resection and individualized reconstruction is a challenging in treat-ment of malignant bone tumor. Three-dimensional (3D)-printing technique is now widely used in the resection and following reconstruction of malignant bone tumor, which included but not limited to tumor model, osteotomy guide and customized implant.Methods: We retrospectively reviewed 17 patients, who underwent limb salvage surgery by using 3D-printed guide at a single center between August 2014 and October 2019. The median duration of follow-up was 26.5 months. Osteosarcoma (41.2%) were the predominant diagnoses. The functional outcomes were assessed by Musculoskeletal Tumor Society (MSTS) functional score. We also analyzed survival status, intraoperative data (blood loss, operation time and resection length), reconstruction method, margin outcomes and complications.Results: We totally performed 93 guided osteotomies on affected bone and allograft bone in 17 patients. Reconstruction in 12 cases was performed with biological technique: allograft combined with autograft was used in 7 cases. 11 of 12 (91.7%) cases showed a good bone healing in both allograft and autograft. 1 of 12 (8.3%) cases had allograft necrosis. Additional intra-operative extracorporeal radiation was performed in 3 pelvic cases for reconstruction. 63 of 64 (98%) osteotomies achieved wide resection and negative margin. All the cases had successful limb salvage result without amputation. At the latest follow up, the mean MSTS Score was 24 (range: 13-30), 12 patients alive with no evidence of disease, 1 patient alive with disease, 5 patients had died of disease and 5 years overall survival is 73.3%. The most common complications are wound healing disorder in 4 cases (23.5%) and infection in 3 cases (17.6%).Conclusion: The 3D-printed resection guide was easy to use and showed promise in the field of orthopedic oncology. It can not only used in primary malignant bone tumor personalized resection but also in shaping structural bone allograft in biological reconstruction, which can achieve a safety surgical margin and individ-ualized resection at the same time.