title: Traumatic isolation of the cervical articular pillar: imaging observations in 21 patients.
abstract: OBJECTIVE
  Imaging studies of patients diagnosed with traumatic isolation of a cervical articular pillar were retrospectively reviewed to better understand the mechanism, clinical significance, and management requirements of this injury.
  
  
  METHODS
  Imaging studies obtained before definitive treatment of 21 patients with traumatic isolation of a cervical articular pillar were reviewed to determine the level and mechanism of injury, fracture patterns, and associated fractures. Lateral cervical radiographs and axial and reformatted sagittal cervical CT images were obtained for all patients. Medical records were reviewed to ascertain the neurologic deficit, if any, and clinical management.
  
  
  RESULTS
  Traumatic isolation of a cervical articular pillar was diagnosed at 24 levels in the 21 patients. The imaging studies indicated that the injury mechanisms producing isolation of the articular pillar were hyperflexion-rotation in 17 patients (81%), hyperflexion-distraction in three patients (14%), and hyperextension-rotation in one patient (5%). A fracture through the transverse foramen ipsilateral to the isolated articular pillar was observed in 19 patients (90%). Contralateral injuries at the level of the isolated articular pillar were present in 14 patients (67%). Neurologic deficits were present in 13 patients (62%) and included spinal cord injury (10) and radiculopathy (3). Eighteen patients underwent surgical reduction and internal stabilization.
  
  
  CONCLUSIONS
  On the basis of an analysis of cervical radiography and CT findings, cervical spine fractures resulting in isolation of an articular pillar most commonly occur from hyperflexion-rotation or hyperflexion-distraction mechanisms. Previous literature has indicated that cervical hyperextension is responsible for this injury, but hyperextension accounted for only one case in this series. It is important to identify the isolated cervical articular pillar as a component of other cervical fracture patterns, as the injury creates two levels of mechanical instability requiring internal fixation of three contiguous vertebrae.
authors.affiliation: Department of Diagnostic Radiology, University of Maryland Medical System, Baltimore 21201, USA.
authors.forename: K
authors.initials: K
authors.lastname: Shanmuganathan
authors.forename: S E
authors.initials: SE
authors.lastname: Mirvis
authors.forename: M
authors.initials: M
authors.lastname: Dowe
authors.forename: A M
authors.initials: AM
authors.lastname: Levine
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed