C1-C2 posterior fixation: indications, technique, and results.

The atlantoaxial motion segment, which is responsible for half of the rotational motion in the cervical spine, is a complex junction of the first (C1) and second (C2) cervical vertebrae. Destabilization of this joint is multifactorial and can lead to pathologic motion with neurologic sequelae. Posterior spinal fixation of the C1-C2 articulation in the presence of instability has been well described in the literature. Early reports of interspinous/interlaminar wiring have evolved into modern-day pedicle screw/translaminar constructs, with excellent results. The success of a C1-C2 posterior fusion rests on appropriate indications and surgical techniques.