Recent Review Article on Os Odontoideum

Volume 7 | Issue 1 | January-June 2022 | Page: 07-11 | Rajendra Sakhrekar, Mohan Gavande, Sriram Srinivasan

DOI: 10.13107/ijs.2020.v07i01.032

Authors: Rajendra Sakhrekar [1], Mohan Gawande [2], Sriram Srinivasan [3], Himanshu G Kulkarni [4]

[1]  Department of Spine Surgery, Hospital for Sick Children, Toronto, Canada.
[2]  Department of Spine Surgery, Kokilaben Dhirubhai Ambani Hospital, Mumbai, Maharashtra, India.
[3] Department of Spine Surgery, Royal Stoke University Hospital, UK.
[4] Department of Spine Surgery, Shraddha Surgical and Accident Hospital, Sangli, Maharashtra, India.

Address of Correspondence
Dr Rajendra Sakhrekar,
Paediatric Spine Fellow, Department of Spine Surgery, Hospital for Sick Children,
Toronto, Canada.



Os-odontoideum is a rare condition, described radiographically and clinically as a congenital anomaly of the second cervical vertebra (axis), it a smooth, independent ossicle of variable size and shape separated from the base of a shortened odontoid process by an obvious gap, with no osseous connection to the body of C2.

Material and methods

This study reviewed the literature on OO to evaluate its etiology, the clinical presentations, differential diagnosis, imaging modalities and outcomes in the management of asymptomatic and symptomatic cases of os odontoideum. PubMed, EMBASE, Google Scholar and Cochrane key articles were searched.


Considering etiology traumatic hypothesis is favoured over congenital hypothesis as per recent literature on OO. Clinical presentation varies from asymptomatic to mild neck pain to severe myelopathy and neurodeficit. Various C1-C2 instrumentation and fusion techniques like wiring, trans articular screw and laminar screws have been described with good success rates.


Os odontoideum is a rare condition with limited existing literature. Considering significant risks involved if conservative management is opted like severe neurodeficit to sudden death on trivial trauma and the recent improvement of imaging tools helping to understand the pathology of the disease, surgery can be indicated even in an incidentally detected os odontoideum. Although for asymptomatic stable patients’ individual case-by-case approach can be considered depending on factors such as age, activity level, comorbidities, syndromic association and radiographic findings.

Keywords: ‘Os-odontoideum’, ‘surgical management’, ‘etiology’, ‘Atlanto-axial instability’ ‘complications’


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How to Cite this Article:  Sakhrekar R, Gawande M, Srinivasan S | Recent Review Article on Os Odontoideum | International Journal of Spine | January-June 2020; 7(1): 07-11.

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