Posterior stabilization of the cervical spine with lateral mass screws.

Abstract

First we performed a closed reduction and ACDF C6–7. After a week, additional posterior stabilization and monosegmental fusion was indicated to provide optimal stability and a good restoration of cervical spine lordosis. Patient is placed in a prone position fixing the head with a Mayfield clamp. Lateral X-ray is helpful for confirming good alignment of the cervical spine. A posterior midline incision is performed down to cervical fascia. Fascia is opened and a subperiosteal exposure of posterior osseous structures C6–7 is performed with electrocautery. Staying in the midline within the ligamentum nuchae helps to avoid bleeding from neck muscles. Care has to be taken not to harm the facet joints that are not intended to be fused. Medial and lateral border of lateral masses are identified. C-arm is positioned laterally to visualize facet joints. Starting points for lateral mass screws are defined by Magerl [2, 3] 2 mm medial and 2 mm caudal to the center of the lateral mass. Cortex is opened by a 1–2 mm burr. The screw trajectory is about 25 –30 lateral and 20 –40 upwards, parallel to the orientation of the facet joint in the