Denis’ three column concept of spine stability
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
