Anderson and D'Alonzo classification of odontoid process fracture

Dr Craig Hacking et al.

The Anderson and D'Alonzo classification is the most commonly used classification of fractures of the odontoid process of C2.

Classification

  • type I
    • rare
    • fracture of the upper part of the odontoid peg
    • above the level of the transverse band of the cruciform ligament
    • usually considered stable
  • type II
    • most common
    • fracture at the base of the odontoid
    • below the level of the transverse band of the cruciform ligament
    • unstable
    • high risk of non-union
  • type III
    • through the odontoid and into the lateral masses of C2
    • relatively stable if not excessively displaced
    • best prognosis for healing because of the larger surface area of the fracture

Another classification system is the Roy-Camille classification.

Share article

Article information

rID: 41604
Synonyms or Alternate Spellings:
  • Anderson and D'Alonzo classification of odontoid process fractures

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Figure 1
    Drag here to reorder.
  • Drag
    Odontoid Fracture...
    Case 1: type II
    Drag here to reorder.
  • Drag
    Case 2: type III
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

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

    Alert accept Thank you for updating your details.