title: Radiographic assessment of thoracolumbar fractures based on axial zones.
abstract: METHODS
  Retrospective study of computed tomography imaging of patients with thoracolumbar (TL) fractures.
  
  
  OBJECTIVE
  To propose an axial model of spinal fractures based on the osteoligamentous continuity of the TL spinal segments in the axial plane and to determine the correlation between the 3-column theory and the proposed axial zone model.
  
  
  BACKGROUND
  Predicting spinal instability of TL fractures is based on several radiologic and clinical parameters. Efforts to refine fracture classification schemes to better predict instability continue.
  
  
  METHODS
  Computed tomography scans of 229 consecutive patients who presented with TL fractures between March 2005 and April 2007 were reviewed. TL fractures were classified according to both the Denis 3-column theory and the proposed axial zone model. The incidence of column and axial zone injuries was determined. On the basis of these results, a treatment algorithm was developed.
  
  
  RESULTS
  Zone disruption in surgical fractures was distributed as follows: 24 (96%) involved zone A, 25 (100%) involved zone B, 17 (68%) involved zone C, and 15 (60%) involved zone D. All surgical fractures involved 2 or more zones. Zone B was involved in all surgical fractures. The likelihood of surgical intervention increased as the number of zones increased, especially if the injury was a 2-column or 3-column injury.
  
  
  CONCLUSIONS
  The current 3-column theory of spinal stability does not account for the axial component of an injury. Application of our proposed "axial zone model" may enhance the ability to predict stability, depending not only on the number of columns, but also on the number of zones involved in the injuries. Further clinical and biomechanical studies are warranted to validate this model.
authors.affiliation: *Department of Neurological Surgery, University of South Florida, Tampa, FL †Spinal Biomechanics Laboratory, Barrow Neurological Institute, Phoenix, AZ ‡Neurosurgical Associates of Los Angeles Inc., Valencia, CA §Division of Neurological Surgery, Barrow Neurological Institute, Phoenix, AZ.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Baaj
authors.forename: Brian R
authors.initials: BR
authors.lastname: Gantwerker
authors.forename: Nicholas
authors.initials: N
authors.lastname: Theodore
authors.forename: Juan S
authors.initials: JS
authors.lastname: Uribe
authors.forename: Fernando L
authors.initials: FL
authors.lastname: Vale
authors.forename: Neil R
authors.initials: NR
authors.lastname: Crawford
authors.forename: Volker K H
authors.initials: VK
authors.lastname: Sonntag
mesh_terms: D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D016103:Spinal Fractures / Q000000981:diagnostic imaging*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed