Tectorial membrane of atlanto-axial joint

The tectorial membrane of atlanto-axial joint (occipitoaxial ligaments) is situated within the vertebral canal.
It is a broad, strong band which covers the dens of the axis, and its ligaments, and appears to be a prolongation upward of the posterior longitudinal ligament of the vertebral column.
It is fixed, below, to the posterior surface of the body of the axis, and, expanding as it ascends, is attached to the basilar groove of the occipital bone, in front of the foramen magnum, where it blends with the cranial dura mater.
Its anterior surface is in relation with the transverse ligament of the atlas, and its posterior surface with the dura mater.