Ferguson Classification of Flexion-Compression Fractures

Type I	Simple anterior wedge compression of the vertebral body, compression not exceeding 50%, middle and posterior columns intact.
Type II	Wedge deformation of the vertebral body with damage to the posterior column ligament complex, widening of the interspinous distance, facet fractures or subluxation, damage to the anterior and posterior columns, middle column intact.
Type III	Compression of the vertebral body, fracture of the posterior superior edge of the vertebral body, fracture fragments protruding into the spinal canal, damage to the anterior, middle, and posterior columns.