Odontoid Fractures: A Review of the Current State of the Art

Abstract

Odontoid fractures (OFs) represent up to 15% of all cervical fractures encountered and present most commonly amongst elderly patients, typically in the setting of low energy trauma such as falls. The Anderson and D'Alonzo classification and Roy-Camille subtype description are the most clinically noteworthy descriptions of OFs used. Even though most patients will not present with neurological injury, mechanical instability can occur with type II and type III (Anderson and D'Alonzo) fractures, particularly if the transverse ligament of the atlas is ruptured; however, this is very rare. Conservative treatment is usually employed for type I and type III injuries, and to a varying degree for non-displaced type II injuries. Surgical treatment is typically reserved for type II fractures, patients with neurological injury, and in the setting of other associated fractures or ligamentous injury. Anterior screw fixation is a viable option in the setting of a favorable fracture line orientation in type II fractures, whereas posterior C1-C2 screw fixation is an option for any type II or type III fracture presentation. There is evidence that surgery for type II fractures has higher rates of union and lower mortality than nonoperative treatments. While surgical options have increased over the decades and the management of OF has been optimized by considering fracture subtypes and patient factors, there remains a significant morbidity and mortality associated with OFs. The aging population and changing demographics suggest that there will be an ongoing rise in the incidence of OFs. Therefore, the appropriate management of these cases will be essential for ensuring optimization of health care resources and the quality of life of affected patients.

Keywords: cervical; elderly; management; non-operative treatment; observation; peg; surgery; trauma.

Figure 1

Classification of Odontoid Fractures according to Anderson and D’Alonzo. Sub-classifications of type II fractures according to Roy-Camille, Hadley, and Grauer. Type IV of Roy-Camille classification is not shown in this figure [9,11,12,13].

Figure 2

Clinical Case of an Anderson and D’Alonzo type II, Roy-Camille type II odontoid fracture: (A) Sagittal CT showing the OF, with some minor posterior displacement of C1 relative to C2, (B) postoperative lateral radiograph, showing a posterior C1–C2 fixation using the Harms-Goel technique, and (C) postoperative midline sagittal CT of the cervical spine showing good realignment of the odontoid post fixation.