Traumatic Posterior Atlantoaxial Dislocation with Intact Odontoid Treated by C2 Laminar Screw Fixation: A Case Report.

Background: Atlantoaxial dislocation (AAD) is a rare but potentially life-threatening condition characterized by an abnormal alignment between the atlas and axis. Traumatic AAD are commonly associated with severe ligamentous injury and may result in spinal cord compression or neurological deficits. Posterior atlantoaxial dislocation with an intact odontoid process and without associated fracture is extremely uncommon and has rarely been reported in literature. Objective: To report a rare case of traumatic posterior atlantoaxial dislocation with an intact odontoid process and describe its management strategy, including emergency reduction and posterior C1-C2 fixation using a C2 laminar screw. Methods: A 51-year-old man was admitted after a traffic accident with severe polytrauma including traumatic brain injury, multiple rib fractures, bilateral hemopneumothorax, splenic injury, and fractures of the left tibia and fibula. Cervical computed tomography revealed a posterior atlantoaxial dislocation without odontoid fracture. Emergency skull traction was performed under general anesthesia with a gradual increase in traction weight from 5 to 10 kg under fluoroscopic guidance. Posterior C1-C2 fixation was subsequently performed because of the redislocation observed on follow-up imaging. Because of a narrow left C2 pedicle and a high-riding vertebral artery, a C2 laminar screw was used as an alternative fixation technique. Results: Intraoperative fluoroscopy and postoperative imaging confirmed a satisfactory reduction and stable fixation of the atlantoaxial complex. However, despite intensive treatment, the patient died 10 days postoperatively due to multiple organ failure secondary to severe polytrauma rather than complications related to the spinal procedure. Conclusion: Emergency skull traction may achieve temporary reduction in traumatic atlantoaxial dislocation; however, surgical stabilization is often required in cases with significant instability. C2 laminar screw fixation is a safe and effective alternative when pedicle screw placement is limited by anatomical variations.