An Interesting Case of Vertebral Artery Pseudoaneurysm Following Posterior C1–C2 Fixation

C1-C2 fixation is a commonly performed procedure for treating cervical spine instabilities, such as Atlanto-axial dislocation (AAD). Although it is generally safe, it can be associated with rare complications, including vertebral artery (VA) injury, which may lead to pseudoaneurysm formation. This case report describes a 12-year-old child who presented with neck pain and was diagnosed with AAD with Basilar invagination. The patient underwent C1-C2 fixation and the post-op hospital stay was uneventful and the patient was discharged. Patient presented again 4 months later with difficulty walking and hand grip weakness. Imaging revealed a VA pseudoaneurysm at the site of left C1 screw placement. The patient was successfully treated with endovascular intervention with flow diverter, leading to clinical improvement. The case highlights the importance of preoperative vascular anatomy assessment, the potential complications of VA injury, and the effectiveness of endovascular management in treating such complications.