Anderson and D'Alonzo classification of odontoid process fracture

Last revised by Mohammad Taghi Niknejad on 26 Nov 2023

Citation, DOI, disclosures and article data

Citation:

Hacking C, Niknejad M, Weerakkody Y, et al. Anderson and D'Alonzo classification of odontoid process fracture. Reference article, Radiopaedia.org (Accessed on 30 Nov 2023) https://doi.org/10.53347/rID-41604

DOI:

https://doi.org/10.53347/rID-41604

Permalink:

https://radiopaedia.org/articles/41604

rID:

41604

Article created:

9 Dec 2015, Craig Hacking ◉ ◈

Disclosures:

At the time the article was created Craig Hacking had no recorded disclosures.

View Craig Hacking's current disclosures

Last revised:

26 Nov 2023, Mohammad Taghi Niknejad ◉

Disclosures:

At the time the article was last revised Mohammad Taghi Niknejad had no financial relationships to ineligible companies to disclose.

View Mohammad Taghi Niknejad's current disclosures

Revisions:

13 times, by 8 contributors - see full revision history and disclosures

Systems:

Musculoskeletal, Spine, Trauma

Sections:

Classifications

Tags:

trauma, snippet title

Synonyms:

Anderson and D'Alonzo classification of odontoid process fractures

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

Another classification system is the Roy-Camille classification, which aids more in the management of odontoid fractures.

Classification

type I
- rare
- fracture of the upper part of the odontoid peg (generally oblique)
- above the level of the transverse band of the cruciform ligament
- usually considered stable
type II
- most common
- transverse course 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 IIa
- type II fractures with comminution at the odontoid base
- Hadley ² described this type of fracture which has a significantly increased risk of nonunion when treated non-operatively compared with classical type II fractures
- represents 5-10% of type II fractures
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