Axis screws: results and complications of a large case series.

OBJECTIVE: To present the surgical results of patients who underwent axis screw instrumentation, discussing surgical nuances and complications of the techniques used.

METHODS: Retrospective case-series evaluation of patients who underwent spinal surgery with axis instrumentation using screws.

RESULTS: Sixty-five patients were included in this study. The most common cause of mechanical instability was spinal cord trauma involving the axis (36 patients - 55.4%), followed by congenital craniocervical malformation (12 patients - 18.5%). Thirty-seven (57%) patients required concomitant C1 fusion. Bilateral axis fixation was performed in almost all cases. Twenty-three patients (35.4%) underwent bilateral laminar screws fixation; pars screws were used in twenty-two patients (33.8%), and pedicular screws were used isolated in only three patients (4.6%). In fourteen patients (21.5%), we performed a hybrid construction. There was no neurological worsening nor vertebral artery injury in this series.

CONCLUSION: Axis screw instrumentation proved to be a safe and efficient method for cervical stabilization. Laminar and pars screws were the most commonly used.