# Application of a Cutting Guide to Optimize Fit of 3D-Printed Patient-Specific Implants in Reconstruction Following Resection of Osseo-Invasive Tumors

## TL;DR

This paper shows how using a cutting guide with 3D-printed implants improves surgery for bone-invading tumors, reducing time and complications.

## Contribution

The use of a resection template to optimize the fit of patient-specific implants during single-stage tumor resection and reconstruction.

## Key findings

- Five patients underwent successful single-stage resection and reconstruction using 3D-printed implants and a cutting guide.
- Accurate implant placement and satisfactory postoperative fit were confirmed via MRI in all cases.
- The approach reduced intraoperative handling and infection risk while improving surgical efficiency.

## Abstract

In managing osseo-invasive tumors, such as meningiomas, the treatment of choice is complete resection, including the dural origin and any involved bone. Virtual preoperative surgical planning, combined with tailored intraoperative reconstruction, can optimize outcomes. Repairing bony defects with patient-specific implants (PSIs) in a single-stage procedure has been shown to reduce operative time and morbidity. Here, we present the use of a resection template to further optimize reconstruction outcomes. We analyzed five patients with cranial tumors exhibiting significant bony invasion who underwent surgery at our institution between June 2023 and January 2025. Tumor resection was virtually planned in collaboration with PSI manufacturers (Synthes®, West Chester, PA, USA, and Protomed®, Westminster, CO, USA), who produced the PSI and corresponding cutting guide for intraoperative use. Among five patients (four men and one woman; mean age: 60 ± 13 years), the mean tumor size was 54.3 ± 12.2 mm × 55 ± 16.4 mm, and the mean operative time was 3.6 ± 1.6 hours. In all cases, resection proceeded as planned, with accurate PSI placement and satisfactory postoperative fit confirmed via magnetic resonance imaging. This retrospective five-case institutional series demonstrates the feasibility of single-stage resection and reconstruction of osseo-invasive cranial tumors using PSI and a resection template to improve fit and reduce intraoperative handling and lower infection risk. This may offer excellent oncological, functional, and cosmetic outcomes by enhancing implant fit and provides simple, accurate, and efficient surgical solution.