[Insertion technique and clinical application of regional method axis pedicle screw]

To explore the clinical efficacies and outcomes of regional method axis pedicle screw insertion technique.

During the period of April 2004 to June 2010, a total of 23 cases with traumatic instability of upper cervical vertebrae were recruited. There were 19 males and 4 females with a mean age of 45.8 years. They underwent surgical operations after an excellent traction reduction of cervical vertebrae. The entry points were drawn on axial facet joint and all of them distributed in the region of upper inner 1/4 of lower articular process. So the regional method was employed to determine the entry point. All subjects underwent the reconstruction of posterior stability. Axial pedicle screws were inserted by the insertion technique of axial pedicle screw via the "regional method". The entry region was in the upper inner 1/4 area of lower articular process. The entry angle, medial inclination and superior inclination were determined by the direction of inner wall and upper wall of isthmus. Postoperative cervical radiography and CT examination were performed to confirm the screw position.

Forty-six axial pedicle screws were implanted. No significant complications occurred. All screws stayed in excellent positions without the invasion of vertebral artery and spinal canal.

The "regional method" insertion technique of axial pedicle screw require no memory of complex entry points and entry angle parameters. And there is no need of identifying the anatomical landmarks. Thus this approach is accurate, safe and suitable for most patients.