Preoperative 3D-CT-based planning for complex craniovertebral junction anomalies: Technique and surgical outcome

The craniovertebral junction (CVJ) is surgically challenging due to its complex anatomy and proximity to vital neurovascular structures. This study aims to evaluate the use of 3D multiplanar reconstruction technique and its impact on surgical and radiological outcomes.

Thirty patients with CVJ anomalies operated on between July 2022 and December 2024 were included. Of the thirty patients, 15 had basilar invagination, six had atlanto-axial dislocation, five had C2 fractures with instability, and four had Arnold-Chiari malformations with instability. Preoperative 3D-computed tomography (CT) and CT angiography reconstructions were performed to evaluate vertebral artery (VA) anatomy, C2 pedicle, C1 lateral mass, C1-C2 facet joint inclination, pseudo-joints, and craniocervical tilt. All patients underwent C1- C2 fixation or occipito-cervical fixation with joint manipulation using spacers. Pre and postoperative neurological recovery were assessed using Nurick and modified Japanese Orthopedic Association grading. Postoperative CT was done in all cases.

Twenty-six underwent C1-C2 fixation and four patients underwent occipito-cervical fixation. No VA injuries or screw-related complications occurred. One patient required revision due to implant failure. Neurological improvement occurred in 90% of cases. Radiological indices (Chamberlain line, McRae line, atlanto-dental interval, clivus canal angle) showed significant postoperative improvement.

Preoperative 3D multiplanar CT reconstruction enables detailed analysis of CVJ anatomy and VA variations, improving safety and surgical outcomes in complex anomalies.