Occipitocervical fusion using contoured rods and medial offset connectors: description of a new technique

Stabilization of the occipitocervical junction and fixation of the occiput is challenging. Rigid fixation with plates and screws has reduced dependence on external immobilization and improved fusion rates. The strength of the occipital fixation can be compromised as plates constrain the ability to place occipital screws along the midline. Bilateral contoured rods with medial offset connectors allow placement of 6 occipital screws in the thickest and strongest bone along the midline, while easily connecting to screws in the cervical spine. The purpose of this study is to review complications and fusion rates in a patient series using this new technique to stabilize the occipitocervical junction. A retrospective review was performed at 2 years of 20 patients who underwent occipitocervical fusion for instability using bilateral contoured rods with medial offset connectors. Six occipital screws were successfully placed in 17 patients. The caudal screw on one side was abandoned in 3 patients due to insufficient occipital thickness. Sixteen patients fused. Four patients died in the perioperative period secondary to polytrauma complications. There were no hardware-related complications nor failure of occipital fixation. Bilateral rods with medial offset connectors allow parasagittal placement of 6 bicortical screws in the thickest and strongest bone along the occipital midline. The use of 6 occipital screws has been shown to be biomechanically advantageous. Using this technique, 6 occipital screws were easily placed in each of 17 patients, while 5 strong points of fixation were obtained in the other 3 patients. We experienced no failure of occipital fixation, and all surviving patients went on to fusion.