The Surgical Treatment Principles of Atlantoaxial Instability Focusing on Rheumatoid Arthritis

Figure 2

Preop reconstructive computed tomography for choosing pedicle screw length and diameter (a), knowing the screw and vertebral artery relationship (asterisk) (b), choosing occiput screw length (c), and the vertebral artery (dashed line) direction (d).

(a)

(b)

(c)

(d)