Harms C1–C2 Instrumentation Technique

Abstract

Convergence and inclination of the pars are slightly greater than the suggested by Harms. Individual and/or racial variations must be considered. There is enough space for safe placement of a 3.5 mm screw in the lateral masses of C1 and through the pars of C2. Dissecting the superior face of the posterior arch of C1 laterally more than 10 mm from the posterior tubercule could injure the vertebral artery.