Simultaneous odontoid excision with bilateral posterior C1-2 distraction and stabilization utilizing bilateral posterolateral corridors and a single posterior midline incision.

A simultaneous odontoid decompression and bilateral posterior atlanto-axial facetal distraction, C1-2 joint spacer/bone graft placement and stabilization may be performed utilizing the 'posterior-only' approach. This procedure may be performed utilizing a single posterior midline incision, a bilateral posterior approach to the C1-2 facet joints and a bilateral posterolateral approach to the odontoid process and C2 body. It may be carried out in situations where a C1-2 non-reduction/partial reduction using a 'posterior alone' procedure is anticipated due to the complex bony/soft tissue configuration anterior at the thecal sac existing at the cervicomedullary junction. In the four cases described in this report, the procedure led to a successful circumferential decompression at the level of foramen magnum along with posterior C1-2 facetal distraction and stabilization in various complex craniovertebral junction anomalies (atlantoaxial dislocation [AAD] and/or a high basilar invagination [BI] associated with a significantly retroverted dens, along with a rotatory component, due to grossly asymmetrical facet joints). This technique may also be utilized in those diseases that result in an anterior osteoligamentous mass at the CVJ associated with C1-2 instability.