Mixed Reality-Assisted Osteotomy Guidance for Single-Stage Skull Tumor Resection and Cranial Reconstruction: A Brief Clinical Study

Single-stage cranial reconstruction using a patient-specific implant (PSI) requires precise intraoperative replication of the preoperative osteotomy plan. Minimal deviations may lead to implant mismatch and the need for intraoperative trimming. The authors report a case of meningioma with skull invasion treated with simultaneous tumor resection and cranial reconstruction using an ultra-high-molecular-weight polyethylene custom implant under mixed reality (MR)-assisted osteotomy guidance. The final 3-dimensional data set used for the implant fabrication was directly imported into the MR device and projected intraoperatively. The hologram scale was fixed preoperatively using a life-sized physical model, and positional alignment was performed intraoperatively using bony landmarks. Osteotomy was executed according to the projected model, allowing precise implant placement without trimming and preservation of the frontal sinus. MR-assisted guidance may enhance the reproducibility of planned osteotomies in single-stage cranial reconstruction while maintaining a unified digital workflow.