Unilateral C1-C2 Posterior Fusion in a Patient With Right Vertebral Artery Anomaly With Intracanal Trajectory: A Case Report.

CASE: A 59-year-old woman presented with progressively worsening neck pain and radicular symptoms. Cervical radiographs revealed C1-C2 dynamic instability. Magnetic resonance imaging and computed tomographic angiogram revealed an anomalous right vertebral artery with intracanal trajectory at C1. A unilateral left C1-C2 fusion with a C1 lateral mass screw and C2 transarticular screw placement was performed due to the anomalous artery. At 14-month follow-up, the patient's cervical symptoms had resolved. CONCLUSION: In this patient with an aberrant vertebral artery who was indicated for C1-C2 fusion, a unilateral contralateral fusion with a C1 lateral mass screw and C2 transarticular screw was a satisfactory treatment option.