Novel 3-Dimensional Printed Lock-and-Key Cutting Guide Mechanism for Single-Stage Customized Reconstruction After Skull Tumor Resection

BACKGROUND AND OBJECTIVES: Skull neoplasms that require surgical resection and alloplastic reconstruction often offer challenges for neurosurgeons in reconstruction. Single-stage reconstruction offers several main advantages and, in fact, alleviates patient burden. Custom cranial implants can be designed to match the anticipated defect, optimizing contour and esthetics. However, reported techniques still require intraoperative custom cranial implant resizing/reshaping. We report the outcomes of a cohort of patients with skull-involving neoplasms who underwent single-stage resection and reconstruction using our 3-dimensional-printed lock-and-key cutting guide, designed to obviate intraoperative implant modification. METHODS: This is a retrospective analysis of a prospectively registered consecutive patients with neoplasms involving the skull who underwent a lock-and-key cutting-guide-directed single-stage reconstruction between August 2022 and October 2025 in a single-center by the senior author. RESULTS: A total of 14 patients were included (9 women), with a mean age of 54 years (range: 19-77 years) and a mean follow-up period of 20 months (range 6-38 months). The final diagnoses included meningiomas, distal metastases, Langerhans cell histiocytosis, benign vascular tumor, and fibrous dysplasia. All cases were successfully treated with our proposed approach. None of the patients developed intraoperative procedure-related complications, wound-related complications, or cranioplasty-related complications during the entire follow-up. None of the cases required intraoperative implant modification. CONCLUSION: In this cohort, the 3-dimensional-printed lock-and-key cutting guide proved to be a feasible, effective, and safe technique for single-stage surgical treatment of neoplasms involving the skull that require alloplastic cranioplasty. In our department, this approach is already considered the gold standard. Compared with other reported methods, we believe our technique represents the new gold standard for single-stage treatment of these neoplasms. Our study adds to the growing body of evidence supporting the refinement of neuro-oncological surgical care, which we refer to and are transitioning to the oncoplastic neurosurgical care.