Safe atlantoaxial fixation using a laminar screw (intralaminar screw) in a patient with unilateral occlusion of vertebral artery: Case report

Study Design. A case of atlantoaxial fusion using an intralaminar (unilateral-crossing laminar screw) screw is presented in a patient with unilateral vertebral artery communication with the basilar artery. Objectives. To document the significance of the intralaminar screw technique in the aforementioned case. Summary of Background Data. Vertebral artery injury is directly linked with intraoperative or perioperative death if the vertebral artery communicates only unilaterally to the basilar artery or has an obvious dominant side. In this situation, irrespective of whether the pedicle is confirmed to be sufficient for pedicle screw placement, if the vertebral artery is violated, fatal complications will occur. The literature reports that even proficient surgeons cannot guarantee 100% accuracy in pedicle screw placement. The intralaminar screw technique is currently the safest with regard to avoiding violation of the vertebral artery. Biomechanical studies have also shown this technique to ensure sufficient strength. Methods. The patient had rheumatoid atlantoaxial subluxation, and the right vertebral artery alone communicated with basilar artery, while the left ended blind. She underwent atlantoaxial fixation with an intralaminar screw (unilateral-crossing laminar screw) of the axis and lateral mass atlas screws inserted via the posterior arch. Results. The intralaminar screw (unilateral-crossing laminar screw) was completed, and comprised lateral mass atlas screws and rods. There were no complications during and after surgery. Good bone union was achieved. Conclusion. Patients with unilateral dominant vertebral artery are good candidates for the intralaminar screw technique, even if the pedicle anatomy is sufficient to insert pedicle screws.