AO Spine Upper Cervical Injury Classification System.
Axis vertebral fracture.
Although not as common as Type II odontoid fractures, other C-2 fractures including hangman's, complex, and Type III odontoid fractures accounted for close to half of the injuries. There are few differences between the fracture types with respect to cause of injury, predisposing factors, or mortality rate. However, surgical treatment was more common for Type II odontoid fractures 1).
1)
Radovanovic I, Urquhart JC, Rasoulinejad P, Gurr KR, Siddiqi F, Bailey CS.
Patterns of C-2 fracture in the elderly: comparison of etiology, treatment, and
mortality among specific fracture types. J Neurosurg Spine. 2017 Aug 18:1-7. doi:
10.3171/2017.3.SPINE161176. [Epub ahead of print] PubMed PMID: 28820364.