Techniques of posterior C1-C2 stabilization

The atlantoaxial complex is an intricate and complex structure accounting for the majority of rotation of the occipitocervical region. Instability of this complex, whether from trauma, inflammation, or congenital disorder, often requires surgical stabilization. Several posterior fusion techniques with varying complexity, risk, and stability have evolved over the past century. The Gallie-type fusion remains the simplest construct, with minimal technical hazards, but provides the least stability and requires halo immobilization after surgery for successful fusion. The Brooks-Jenkins, Sonntag's modified Gallie, and interlaminar clamp techniques all provide comparable stability with low complication rates, although postoperative halo immobilization is often recommended. The transarticular screw technique of Magerl results in the most stable construct of all of the posterior fusion techniques in anteroposterior translation and rotation, obviating the need for postoperative halo immobilization. A review of the clinical and biomechanical data regarding transarticular screw fixation reveals a fusion rate of 93.7% and low complication rates. However, this technique is also the most technically demanding, and successful screw placement requires careful preoperative planning, strict attention to anatomic landmarks, and intraoperative fluoroscopy to prevent damage to the vertebral arteries.