3D-Customized Guiding Template for Posterior Fixation in Complex Atlantoaxial Instability—Preliminary Experiences of National Cheng Kung University Hospital

Abstract

Objective Atlantoaxial fixation is technically demanding and challenging, especially in cases with anatomical abnormality. The purpose of this study is to report the effectiveness of the three-dimensional (3D)-customized guiding template for placement of C1 and C2 screws in cases with abnormalities. Method Two patients with anatomical abnormality and one without were included. The preoperative computed tomography (CT) image was analyzed using our software. The entry point, trajectory, and depth of the screws were designed based on these images. Templates with screw guiding cylinders and cervical spine model were created. In operation, guiding templates were applied directly to the laminae. Drilling, tapping, and screwing were performed through the cylinders. To evaluate the accuracy, deviation of the screw axis from the preplanned trajectory was measured on postoperative CT. A classification system was taking to evaluate the pedicle screw insertion. Results In complex cases, one of C2 screws has grade 2 deviation, and two has grade 1. There was no deviation in screws of C1. All patients achieved symptoms free after 6 months follow-up. Conclusion Although 3D-printed template for atlantoaxial fixation still has limitation in complex cases, it has been proved usefulness and makes the most difficult and dangerous spinal posterior fixation easy to achieve.

The application of 3D printing in neurosurgery: present and future

“…general surgery, maxillofacial surgery) or dentistry are dominated by the topic of implantology and intraoperative use of models [23]. It would seem that it should be analogous in neurosurgery (spinal implants, dedicated interbody cages, stabilizing screws) [24][25][26][27][28][29][30]. The reason for this discrepancy may lie in the potential costs of such implants, which are so far higher than the standard spinal surgery implants [24][25][30][31][32].…”

“…It would seem that it should be analogous in neurosurgery (spinal implants, dedicated interbody cages, stabilizing screws) [24][25][26][27][28][29][30]. The reason for this discrepancy may lie in the potential costs of such implants, which are so far higher than the standard spinal surgery implants [24][25][30][31][32]. The same applies to the cost of printing cranial defects in reparative surgery compared to intraoperative manual fabrication of such defects from a plastic mass (polymethyl methacrylate, PMMA) [11,14,19,33].…”

“…Currently in the literature, the use of additive printing in neurosurgery focuses on cranial bone repair surgeries and much less frequently on spinal surgeries [14,[25][26]41]. Restorative operations include craniosynostosis-related procedures in the pediatric patients and in adults, the replenishment of the cranial bone after a craniectomy [11,14,41].…”