Management of Basilar Invagination

Abstract

Basilar invagination (BI) is a development anomaly of the craniocervical junction that results in a prolapsed of the upper cervical spine into the skull base, commonly associated to other bone and neural axis abnormalities, like Chiari I malformation and syringomyelia. In this paper, we review the concepts necessary to understand and treat BI. The most comprehensive and accepted classification system is the proposed by Goel, which divides patients with BI into two groups, as it follows: group A) patients with clear elements of instability; and group B) BI secondary to clivus hypoplasia. Treatment in group A includes craniocervical realignment and stabilization, most of the times using an isolated posterior approach, obviating an unnecessaryand morbidity of the anterior decompression. In group B, foramen magnum decompression is the treatment of choice. Surgical techniques should be adequate according to patient’s anatomy and surgeon’s experience. Good surgical results can be obtained with the understanding of the main concepts and treatment options of BI.