The upper cervical spine is said to be consist of  two unique vertebrae, the atlas (C1) and the axis C2). The skull base with its bony and ligamentous elements surrounding the foramen magnum plays an integral part in maintenance of the normal functional alignment of these two cervical vertebrae.

Technically however, skull base is not a part of upper cervical spine.

But the injuries to upper cervical spine also include all osseous and ligamentous structures between the skull base and the cranial side of the C-3 vertebra. [Read more...]