An alternate method for placement of C-1 screws.

Abstract

Several techniques for the surgical stabilization of the atlas and the axis have been described. Placement of C-1 lateral mass screws is one of the latest technical advances, and has gained popularity due to its efficacy and biomechanical advantages. However, the technique for placement of C-1 lateral mass screws, as first described by Harms, can cause excessive bleeding or irritation of the C-2 nerve. An alternative technique is available for the placement of C-1 lateral mass screws that completely avoids the C-2 nerve/ganglion and its associated venous plexus. This new technique mitigates some of the risk associated with the Harms techniques and eliminates the need to use specialized screws (that is, smooth shanks). Twenty-six patients underwent atlantoaxial or occipitocervical fusions incorporating the alternative technique of C-1 screw placement. Three surgeons at 3 different institutions performed the surgeries. Standard lateral fluoroscopy and fully threaded polyaxial screws were used in each case. Forty-nine screws were placed in C-1 lateral masses by using the new technique. Solid arthrodesis was achieved in all cases, with a mean follow-up period of 30 months. There were no cases of CSF leakage, new neurological deficit, injury to the C-2 ganglion, vertebral artery injury, or hardware failures. The technique is a safe and effective way to fixate C-1 while avoiding the C-2 nerve/ganglion and venous plexus. The results indicate that excellent clinical and radiographic outcomes can be achieved with this new technique.