Malformations of the atlas vertebra simulating the Jefferson fracture

AJR Am J Roentgenol. 1983 Jun;140(6):1083-6. doi: 10.2214/ajr.140.6.1083.


Congenital clefts and aplasias of the atlas vertebra, while rare, are often first encountered in the emergency room setting. Thirty-six patients with atlas malformations and 10 with Jefferson fractures were encountered. Sixteen of the patients with congenital malformations showed bilateral atlantoaxial lateral offset, a finding generally considered to be the result of fracture. The diagnosis of these abnormalities is readily made from plain films by noting their characteristic features. Anomalies produce lateral offset of 1-2 mm. Jefferson fractures produce a greater offset (over 3 mm).

MeSH terms

  • Atlanto-Occipital Joint / diagnostic imaging
  • Atlanto-Occipital Joint / injuries*
  • Cervical Atlas / abnormalities*
  • Cervical Atlas / diagnostic imaging
  • Fractures, Bone / diagnostic imaging*
  • Fractures, Closed / diagnostic imaging*
  • Humans
  • Radiography