The New Alternative Technique Outcomes: Atlas Lateral Mass Screw and C2-3 Transfacet Screw Fixation for Complex Atlantoaxial Instability in Patients with Thin C2 Pedicle or High-Riding Vertebral Artery

OBJECTIVE: The study aimed to evaluate the safety, feasibility, effect on fusion, and clinical efficacy of atlas lateral mass and C2-3 transfacet screw fixation technique, serves as an alternative method to traditional posterior atlantoaxial fixation. METHODS: Patients with atlantoaxial instability who underwent atlas lateral mass and C2-3 transfacet fixation surgery were included. The duration of the surgery and the quantity of blood lost during the operation were recorded. Patients were monitored via X-ray and computed tomography scans to evaluate the degree of fusion at the 1-month and 12-month follow-up. The Neck Visual Analog Scale and Neck Disability Index were evaluated preoperatively, in the postoperative first week, and at the 12-month follow-up for clinical follow-up. RESULTS: A total of 8 patients with atlantoaxial instability due to odontoid fracture or Arnold- Chiari malformation accompanied by bony or vascular abnormalities were included in the study between 2017 and 2024. All 8 patients underwent successful atlas lateral mass and C2-3 transfacet screw fixation, with no neurovascular injury noted during surgery. All patients with fracture exhibited fusion at the 12-month mark, and both the Neck Visual Analog Scale and Neck Disability Index scores demonstrated significant improvement at both the 1-week and 12-month postoperative periods (P< 0.05). CONCLUSIONS: The atlas lateral mass and C2-3 trans- facet screw fixation technique, an alternative to conventional posterior fixation, has been demonstrated to be an efficacious method for providing adequate stabilization and fusion in patients with atlantoaxial instability, even in the cases of thin C2 pedicle, high-riding vertebral artery, previous failed surgeries, or reoperation.