Surgical Anatomy of the Upper Cervical Spine and the Craniocervical Junction

Abstract

The craniocervical junction consists of the occipital bone, the atlas, and the axis vertebras. Motion among these three bones is determined by the shape and orientation of their joint surfaces and guided by their ligaments. The medulla oblongata is found at the level of the clivus and the foramen magnum; the lower levels contain the spinal cord. This chapter focuses on the detailed bony anatomy of the occipital bone, the atlas, and the axis vertebras. The relevant ligamentous structures of the craniocervical junction, the cruciform ligament, the paired alar and accessory ligaments, the apical ligament, and the tectorial membrane are discussed. Finally a brief overview on the suboccipital muscles and nerves of this region is given.