Three column concept of spinal fractures

The three column concept of thoracolumbar spinal fractures was initially devised by Francis Denis.  CT is mandatory for an accurate classification.

While initially developed for classification of thoracolumbar spinal fractures, it can also be applied to the lower cervical spine 3 as the general vertebral anatomy is similar to thoracic and lumbar vertebrae. Due to its simplicity, it is widely used in routine clinical practice. 


Denis divided the vertebral column into 3 vertical parallel columns based on biomechanical studies related to stability following traumatic injury. Instability occurs when injuries affect 2 contiguous columns (i.e. anterior and middle column or middle and posterior column). Obviously a 3 column injury is also unstable.

The three columns are: 


In his original article in 1976 1, Denis differentiated five types of fractures A-E:

  • type A
    • fracture of both endplates without kyphosis
    • mechanism of injury: pure axial load
    • predilection site: low lumbar region
  • type B
    • fracture of the superior endplate (CT may also demonstrate a sagittal split of the lower endplate)
    • most frequent burst fracture
    • mechanism of injury: axial load and flexion
    • predilection site: thoracolumbar junction
  • type C
    • fracture of the inferior endplate
    • rare
    • mechanism of injury: probably axial load and flexion.
    • no particular site pattern could be identified
  • type D
    • burst rotation fracture
    • burst fracture with comminution of the vertebral body, large central defect on CT, loss of posterior height, increase of the interpedicular distance, vertical fracture of the lamina, bone retropulsed into the spinal canal
    • mechanism of injury: axial load and rotation
    • predilection site: mid lumbar region
  • type E
    • burst lateral flexion fracture
    • fractured posterior wall of the vertebral body with fragment extrusion towards the side of the flexion
    • mechanism of injury: axial load and lateral flexion
Spinal trauma
Share article

Article information

rID: 15488
Synonyms or Alternate Spellings:
  • Thoracolumbar spinal fractures : three column concept
  • Denis classification of thoracolumbar spinal fracture
  • Three column concept of thoracolumbar spinal fractures
  • Denis classification

Support Radiopaedia and see fewer ads

Cases and figures

  • Figure 1: illustration
    Drag here to reorder.
  • Case 1: burst fracture - Denis type B
    Drag here to reorder.
  • Case 2: three column thoracic spine fracture
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.