What are ligaments?

If the spinal column is designed to provide stability and protection, what holds the bones together? Ligaments, similar to oversized rubber bands, criss–cross to hold the spinal column together. Ligaments are fibrous and strong tissues that connect bone, cartilage, and other structures supporting the spinal system. There are three major types of ligaments found in the spine.

1. The anterior longitudinal ligament runs in the front (anterior) and vertically (longitudinal) attaching to the front of each vertebra.

2. The posterior longitudinal ligament runs vertically behind (posterior) and inside the spinal canal from the brain to the tailbone.

3. The third ligament, the ligamentum flavum, acts as a protective hood over the dura mater. This ligament connects under the facet joints and forms a little curtain over the posterior opening between the vertebrae. This curtain can be pushed aside during surgery to allow the physician access to the spinal canal.

Smaller ligaments that attach to the vertebral bodies to further safeguard the spine against bending too far in any direction join the three ligament systems.

Three of the more important ligaments in the spine are the Ligamentum Flavum, Anterior Longitudinal Ligament and the Posterior Longitudinal Ligament.

• The Ligamentum Flavum forms a cover over the dura mater: a layer of tissue that protects the spinal cord. This ligament connects under the facet joints to create a small curtain over the posterior openings between the vertebrae.
• The Anterior Longitudinal Ligament attaches to the front (anterior) of each vertebra. This ligament runs up and down the spine (vertical or longitudinal).
• The Posterior Longitudinal Ligament runs up and down behind (posterior) the spine and inside the spinal canal.

Primary Spinal Ligaments Include:

Ligament Systems – Atlas and Axis
As mentioned in the discussion of the cervical spine, the Atlas (C1) and Axis (C2) are different from the other spinal vertebrae. The upper cervical ligament system is especially important in stabilizing the upper cervical spine from the skull to C2. Although the cervical vertebrae are the smallest, the neck has the greatest range of motion.

Occipitoatlantal Ligament Complex (Atlas)
These four ligaments run between the Occiput and the Atlas:
 

• Anterior Occipitoatlantal Ligament
• Posterior Occipitoatlantal Ligament
• Lateral Occipitoatlantal Ligaments (2)

Occipitoaxial Ligament Complex (Axis)
These four ligaments connect the Occiput to the Axis:
 

• Occipitoaxial Ligament
• Alar Ligaments (2)
• Apical Ligament
   

Altantoaxial Ligament Complex (Axis)
These four ligaments extend from the Atlas to the Axis:
 

• Anterior Atlantoaxial Ligament
• Posterior Atlantoaxial Ligament
• Lateral Ligaments (2)

Cruciate Ligament Complex
These ligaments help to stabilize the Atlantoaxial (Axis) complex:
 

• Transverse Ligaments
• Superior Longitudinal Fascicles
• Inferior Longitudinal Fascicles

Tendons are also an integral part of the spine. These sturdy bands of tissue attach muscles to bones. Tendons vary in length, thickness, and elasticity.