Denis Gave How Many Columns to Define Stability of Spine (DNB Dec 2009)
Denis' Three-Column Theory
a. Proposed by Francis Denis, three-column concept divides a spinal segment into three parts: anterior, middle, and posterior colums.
b. The anterior column comprises the anterior longitudunal ligament and the anterior half of the vertebral body; the middle column comprises the posterior half of the vertebral body and the posterior longitudunal ligament; the posterior column comprises the pedicles, the facet joints and the supraspinous ligaments.
Significance: if 2 out of 3 columns are involved it is labeled as unstable spinal injury.