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Atlanto-occipital dissociation
From WikEM
Contents
Background
- Unstable spine fractures
- Tectorial membrane and alar ligaments provide stability to atlanto-occipital joint
- Injury or laxity of these ligaments can lead to subluxation or dislocation
- Also referred to as internal decapitation
- Down syndome predisposes to atlanto-occipital dislocation
Clinical Features
- Pure flexion injury involving C1-C2, with or without odontoid fracture
- Often associated with brain injury, which predicts mortality[1]
Differential Diagnosis
Cervical Spine Fractures and Dislocations
- Atlanto-occipital dissociation
- C1
- C2
- C3-C7
- Cervical facet dislocation
Evaluation
- Evaluate with the Powers ratio
- Ratio of BC:OA > 1 suggests anterior subluxation
- BC = distance between basion and midpoint of C2 post laminar line
- OA = Distance between opisthion and ant arch of C2
- Basion to dens interval of > 10mm [2]
Management
Prehospital Immobilization
See the NAEMSP National Guidelines for Spinal Immobilization
Hospital
- C-collar
- Consult ortho or spine as needed
Disposition
- Admit
See Also
External Links
References
- ↑ Mendenhall, S. K., Sivaganesan, A., Mistry, A., Sivasubramaniam, P., McGirt, M. J. and Devin, C. J. (2015) ‘Traumatic atlantooccipital dislocation: Comprehensive assessment of mortality, neurologic improvement, and patient-reported outcomes at a level 1 trauma center over 15 years’, The Spine Journal, 15(11), pp. 2385–2395
- ↑ Riascos R, Bonfante E, Cotes C et-al. Imaging of Atlanto-Occipital and Atlantoaxial Traumatic Injuries: What the Radiologist Needs to Know. Radiographics. 2015;35
