The ligament gradually grows narrower inferiorly.[2] The ligament is thicker in the thoracic than in the cervical and lumbar regions. In the thoracic and lumbar regions, it presents a series of dentations with intervening concave margins.[citation needed]
The posterior longitudinal ligament is generally quite wide and thin,[1] and has serrated edges.[2] It is narrow at the vertebral bodies (where it is firmly attached[2] and where it covers the basivertebral veins[1]), and broader over the intervertebral discs (to which it attaches less firmly to allow for the passage of the basivertebral veins[2]).[1][2]
Structure
This ligament is composed of smooth, shining, longitudinal fibers - denser and more compact than those of the anterior longitudinal ligament - and consists of superficial layers occupying the interval between three or four vertebræ, and deeper layers which extend between adjacent vertebrae.[4] Deep fibres run between each vertebral body.[1] Superficial fibres run between multiple vertebrae.[1]