Safety of atlantoaxial fusion using laminar and transarticular screws combined with an atlas hook in a patient with unilateral vertebral artery occlusion (case report)

Objective and importance: A disadvantage of transarticular and C2 pedicle screws is vertebral artery (VA) injury as a result of screw misplacement. If unilateral occlusion of the VA is present, VA injury of the dominant side will cause fatal complications as a result of collateral flow insufficiency. Several authors have recently reported the usefulness of C2 laminar screws because of their safety on VA injury. We used transarticular and C2 laminar screws combined with the atlas hook in a patient with C1-2 instability and unilateral VA occlusion, in order to reduce the risk of further VA injury. Clinical presentation: A 64-year-old woman with rheumatoid atlantoaxial subluxation complained of cervical myelopathy and neck pain. Preoperative MR angiography showed a left side VA occlusion. Technique: The patient underwent atlantoaxial, posterior fusion using a transarticular screw on the side of the occlusion and a C2 laminar screw on the dominant side combined with a bilateral atlas hook. The transarticular screw was inserted using a navigation system and image intensifier, and the laminar screw was inserted free hand. Bone grafting from the iliac crest was performed. Conclusion: Transarticular and C2 laminar screws fixation combined with the atlas hook in a patient with unilateral VA occlusion is a useful technique, in order to reduce the risk of further VA injury.