Basilar Invagination: Surgical Treatment by Novel Anterior Implant

Introduction: Anterior retropharyngeal realignment, distraction, and atlantoaxial fixation are an option for the treatment of symptomatic basilar invagination (BI). The anterior implants for distraction and fixation for atlantoaxial joints are still evolving. We share our experience using a novel implant which can easily, safely, and rigidly fix both lateral masses to the body of the axis. Methods: After exposing both the atlantoaxial joints anteriorly, the joints were prepared, distracted with wedge shaped autologous tricorticate bone grafts and realigned to correct the cervicomedullary strain. The atlantoaxial joints were fixed using a novel titanium plate by passing screws upwards and laterally into the lateral masses of the atlas and centrally into the body of the axis. Post-operative imaging showed effective correction of BI and atlantoaxial dislocation. Post-operative dynamic X-ray images confirmed maintenance of rigid fixation at 6 months. Conclusion: This new plate screw construct is safe, easy, cost-efficient, and biomechanically appealing option for the treatment of symptomatic BI. Keywords: Basilar invagination, atlantoaxial dislocation, vertebral artery injury, atlantoaxial fixation, atlantoaxial instability.