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Collaborative Hypertext of Radiology

Musculoskeletal system



axis fracture

  • incidence: 6% of cervical spine injuries
  • associated with atlas fractures in 8%

  • hyperflexion injury: odontoid fracture
    type I
    avulsion of tip of odontoid (5-8%)
    difficult to detect
    type II
    fracture through base of dens (54-67%)
    complication: nonunion
    type III
    subdental injury (30-33%)
    prognosis: good
    • DDx:
      • os odontoideum
      • ossiculum terminale
      • hypoplasia/aplasia of dens

  • hyperextension injury: hangman's fracture

Yong H. Hahn, MD  -  2 February 1995
Last updated:  1 October 2013


Related CHORUS documents:
cervical spine fractures
atlas fracture
hangman's fracture
Jefferson fracture
tear drop fracture
unstable cervical spine fractures


Copyright © 2013, Charles E. Kahn, Jr.