Denis’ three column concept of spine stability

Source:http://pgblazer.com/2009/11/three-column-concept-of-spine-stability.html

Stable spine is one which after the initial injury does not get displaced further. The spine is stable when atleast 2 columns of the spine are intact.

Denis’ three column concept of spine stability
According to the three column concept, the spine is considered to have 3 columns:

Anterior
Middle
Posterior


The anterior column is composed of:
Anterior longitudinal ligament
Anterior half of vertebral body and intervertebral disc


The middle column is composed of:
Posterior longitudinal ligament
Posterior half of vertebral body and intervertebral disc


The posterior column is composed of:
Transverse process
Spinous process
Pedicle
Lamina
Faceted joints
Interspinous ligament
Supraspinous ligament
Ligamentum flavum


Spinal injury and Three column concept:
One column injury is stable
Two column injury is unstable
Three column injury is invariably unstable

In adition to proposing the 'three column spine' Denis also defined four types of spinal fractures;

• wedge fracture - stable
• burst fracture - stable
• seat belt fracture (and 'Chance fracture') - unstable
• fracture dislocation - unstable