Rationale:Because of the risk of C1 to C2 instability, which would reduce the mobility of the occipito-atlanto-axis articulation, unstable C1 semi-ring fractures are typically treated with C1 to C2 or C0 to C2 fusion. The vertebral artery and spinal cord are at risk of harm during the installation of C1 pedicle screws. There is a need for a method that can maintain the occipito-atlanto-axis articulation’s mobility and increase the safety of C1 pedicle screw fixation, particularly for surgeons who have less experience inserting C1 pedicle screws freehand.Patient concerns:A 45-year-old man who had suffered a severe fall from a height of 2.5 m presented with pain in his cervical spine. Magnetic resonance imaging and computed tomography were used to diagnose unstable atlas fractures.Diagnosis:According to radiographic studies, the patient had a unilateral anterior and posterior arch fracture (semi-ring fracture, Landells type II), as well as fractures and transverse ligament avulsion at the attachment site.Interventions:We fixed the C1 directly with a pedicle screw using a navigational template.Outcomes:Both during and after the operation, there were no connected complications. Imaging at 12 months after surgery demonstrated that the fracture had united. The average visual analog scale score decreased from 8 before surgery to 2.Lessons:In particular for surgeons with less experience placing freehand C1 pedicle screws, direct C1 pedicle screw fixation with the aid of a navigational template was a good option because it can preserve the mobility of the occipito-atlanto-axis articulation and improve the safety of C1 pedicle screw.