Inferior longitudinal band of cruciform ligament

The inferior longitudinal band of the cruciform ligament is a component of the cruciform (cruciate) ligament complex at the craniovertebral junction. It is a longitudinal fibrous band that extends from the transverse ligament of the atlas inferiorly to attach to the posterior aspect of the body of the axis (C2 vertebra). This structure, together with the superior longitudinal band (which extends superiorly to the occipital bone), forms the vertical limb of the cruciform ligament, with the transverse ligament forming the horizontal limb.

The inferior longitudinal band helps stabilize the odontoid process (dens) of the axis against the anterior arch of the atlas, thereby contributing to the stability of the atlantoaxial joint and preventing excessive movement or cranial migration of the dens, which could compromise the spinal cord.