Bookmarks
KEY FACTS
Terminology
Imaging
Top Differential Diagnoses
Pathology
Clinical Issues
Diagnostic Checklist
TERMINOLOGY
Synonyms
- Ossicle (Os)
Definitions
- Corticated, oval or round os at odontoid process tip
- 2 types described based on position of os
- Orthotopic: Os in normal position of odontoid tip
- Dystopic: Os in any other location
- Most commonly, os located near foramen magnum, may fuse with clivus (os avis) or anterior C1 ring
IMAGING
General Features
Radiographic Findings
CT Findings
MR Findings
Imaging Recommendations
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Staging, Grading, & Classification
Gross Pathologic & Surgical Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Selected References
- Goel A et al: Os odontoideum: analysis of 190 surgically treated cases. World Neurosurg. 134:e512-23, 2020
- Helenius IJ et al: Os odontoideum in children: treatment outcomes and neurological risk factors. J Bone Joint Surg Am. 101(19):1750-60, 2019
- Sato H et al: Familial Os odontoideum: proatlas segmentation abnormality. World Neurosurg. 130:146-9, 2019
- Buyukkaya A et al: Characteristic imaging findings of os odontoideum. Spine J. 14(12):3052-3, 2014
- Kulkarni GB et al: Profile oF patients with craniovertebral junction anomalies with posterior circulation strokes. J Stroke Cerebrovasc Dis. 23(10):2819-26, 2014
- Visocchi M et al: Os odontoideum syndrome: pathogenesis, clinical patterns and indication for surgical strategies in childhood. Adv Tech Stand Neurosurg. 40:273-93, 2014
- Pang D et al: Embryology and bony malformations of the craniovertebral junction. Childs Nerv Syst. 27(4):523-64, 2011
- Arvin B et al: Os odontoideum: etiology and surgical management. Neurosurgery. 66(3 Suppl):22-31, 2010
- Visocchi M et al: Reducible and irreducible os odontoideum in childhood treated with posterior wiring, instrumentation and fusion. Past or present? Acta Neurochir (Wien). 151(10):1265-74, 2009
- Wada E et al: Os odontoideum as a consequence of a posttraumatic displaced ossiculum terminale. A case report. J Bone Joint Surg Am. 91(7):1750-4, 2009
- Klimo P Jr et al: Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients. J Neurosurg Spine. 9(4):332-42, 2008
- Menezes AH et al: Anatomy and biomechanics of normal craniovertebral junction (a) and biomechanics of stabilization (b). Childs Nerv Syst. 24(10):1091-100, 2008
- Menezes AH: Craniocervical developmental anatomy and its implications. Childs Nerv Syst. 24(10):1109-22, 2008
- Menezes AH: Craniovertebral junction database analysis: incidence, classification, presentation, and treatment algorithms. Childs Nerv Syst. 24(10):1101-8, 2008
- Smoker WR et al: Imaging the craniocervical junction. Childs Nerv Syst. 24(10):1123-45, 2008
- Gupta V et al: Dynamic magnetic resonance imaging evaluation of craniovertebral junction abnormalities. J Comput Assist Tomogr. 31(3):354-9, 2007
- Klimo P Jr et al: Congenital anomalies of the cervical spine. Neurosurg Clin N Am. 18(3):463-78, 2007
- Choit RL et al: Os odontoideum: a significant radiographic finding. Pediatr Radiol. 35(8):803-7, 2005
- Vargas TM et al: Atlantoaxial instability associated with an orthotopic os odontoideum: a multimodality imaging assessment. Emerg Radiol. 11(4):223-5, 2005
Related Anatomy
Loading...
Related Differential Diagnoses
Loading...
References
Tables
Tables
KEY FACTS
Terminology
Imaging
Top Differential Diagnoses
Pathology
Clinical Issues
Diagnostic Checklist
TERMINOLOGY
Synonyms
- Ossicle (Os)
Definitions
- Corticated, oval or round os at odontoid process tip
- 2 types described based on position of os
- Orthotopic: Os in normal position of odontoid tip
- Dystopic: Os in any other location
- Most commonly, os located near foramen magnum, may fuse with clivus (os avis) or anterior C1 ring
IMAGING
General Features
Radiographic Findings
CT Findings
MR Findings
Imaging Recommendations
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Staging, Grading, & Classification
Gross Pathologic & Surgical Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Selected References
- Goel A et al: Os odontoideum: analysis of 190 surgically treated cases. World Neurosurg. 134:e512-23, 2020
- Helenius IJ et al: Os odontoideum in children: treatment outcomes and neurological risk factors. J Bone Joint Surg Am. 101(19):1750-60, 2019
- Sato H et al: Familial Os odontoideum: proatlas segmentation abnormality. World Neurosurg. 130:146-9, 2019
- Buyukkaya A et al: Characteristic imaging findings of os odontoideum. Spine J. 14(12):3052-3, 2014
- Kulkarni GB et al: Profile oF patients with craniovertebral junction anomalies with posterior circulation strokes. J Stroke Cerebrovasc Dis. 23(10):2819-26, 2014
- Visocchi M et al: Os odontoideum syndrome: pathogenesis, clinical patterns and indication for surgical strategies in childhood. Adv Tech Stand Neurosurg. 40:273-93, 2014
- Pang D et al: Embryology and bony malformations of the craniovertebral junction. Childs Nerv Syst. 27(4):523-64, 2011
- Arvin B et al: Os odontoideum: etiology and surgical management. Neurosurgery. 66(3 Suppl):22-31, 2010
- Visocchi M et al: Reducible and irreducible os odontoideum in childhood treated with posterior wiring, instrumentation and fusion. Past or present? Acta Neurochir (Wien). 151(10):1265-74, 2009
- Wada E et al: Os odontoideum as a consequence of a posttraumatic displaced ossiculum terminale. A case report. J Bone Joint Surg Am. 91(7):1750-4, 2009
- Klimo P Jr et al: Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients. J Neurosurg Spine. 9(4):332-42, 2008
- Menezes AH et al: Anatomy and biomechanics of normal craniovertebral junction (a) and biomechanics of stabilization (b). Childs Nerv Syst. 24(10):1091-100, 2008
- Menezes AH: Craniocervical developmental anatomy and its implications. Childs Nerv Syst. 24(10):1109-22, 2008
- Menezes AH: Craniovertebral junction database analysis: incidence, classification, presentation, and treatment algorithms. Childs Nerv Syst. 24(10):1101-8, 2008
- Smoker WR et al: Imaging the craniocervical junction. Childs Nerv Syst. 24(10):1123-45, 2008
- Gupta V et al: Dynamic magnetic resonance imaging evaluation of craniovertebral junction abnormalities. J Comput Assist Tomogr. 31(3):354-9, 2007
- Klimo P Jr et al: Congenital anomalies of the cervical spine. Neurosurg Clin N Am. 18(3):463-78, 2007
- Choit RL et al: Os odontoideum: a significant radiographic finding. Pediatr Radiol. 35(8):803-7, 2005
- Vargas TM et al: Atlantoaxial instability associated with an orthotopic os odontoideum: a multimodality imaging assessment. Emerg Radiol. 11(4):223-5, 2005
