Anterior longitudinal ligament
Ligamentum longitudinale anterius
A long, broad band running down the front of the vertebral column, over every vertebral body and intervertebral disc.
At a glance
- English
- Anterior longitudinal ligament
- Latin (TA2)
- Ligamentum longitudinale anterius
- System
- Ligament
- Region
- Neck
- Side
- Single, on the midline
About the anterior longitudinal ligament
This long, strong strip of fibrous tissue lies on the front of the spine. It starts at the base of the skull, on the basilar part of the occipital bone and the anterior tubercle of the atlas, and runs the full length of the column to the front of the upper sacrum. Along the way it covers the anterior surfaces of the vertebral bodies and the discs between them.
Its shape changes along its course. In the thoracic region it is narrow and thick, while in the neck and lower back it is broader and thinner. It is also slightly thicker and narrower where it crosses a vertebral body and thinner but a little wider over a disc, although this variation is much less marked than in the posterior longitudinal ligament. Its fibres are arranged in layers: the deepest join neighbouring vertebrae, an intermediate layer spans two or three, and the most superficial fibres reach across three or four.
The ligament is firmly bound to the discs and to the margins of the vertebral bodies but more loosely attached across their middles. Its main job is to resist extension of the spine; it is the only ligament on the front of the column, so it tightens whenever the back arches. It also supports the front of the discs against bulging forwards.
Several conditions affect it. In diffuse idiopathic skeletal hyperostosis the ligament gradually calcifies and turns to bone, stiffening the spine and causing back pain. Violent hyperextension, as in a whiplash injury, can tear it. In spinal surgery it may be deliberately released, or partly cut, between two vertebrae to correct an abnormal forward curve such as kyphosis, although osteoporosis, infection or previous surgery can make this unsafe.
Attachments and function
- Attaches from
- The basilar part of the occipital bone and the anterior tubercle of the atlas.
- Attaches to
- The pelvic surface of the upper sacrum, after attaching to every vertebral body and disc on the way.
- Function
- Limits extension of the vertebral column and supports the front of the intervertebral discs.
Anthromica
See the anterior longitudinal ligament where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
