Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Case 19 Variants of the upper cervical spine
- Case 20 Atlantoaxial rotatory fixation versus head rotation
- Case 21 Cervical flexion and extension radiographs after blunt trauma
- Case 22 Pseudosubluxation of C2–C3
- Case 23 Calcific tendinitis of the longus colli
- Case 24 Motion artifact simulating spinal fracture
- Case 25 Pars interarticularis defects
- Case 26 Limbus vertebra
- Case 27 Transitional vertebrae
- Case 28 Subtle injuries in ankylotic spine disorders
- Case 29 Spinal dural arteriovenous fistula
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Case 20 - Atlantoaxial rotatory fixation versus head rotation
from Section 2 - Spine
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Case 19 Variants of the upper cervical spine
- Case 20 Atlantoaxial rotatory fixation versus head rotation
- Case 21 Cervical flexion and extension radiographs after blunt trauma
- Case 22 Pseudosubluxation of C2–C3
- Case 23 Calcific tendinitis of the longus colli
- Case 24 Motion artifact simulating spinal fracture
- Case 25 Pars interarticularis defects
- Case 26 Limbus vertebra
- Case 27 Transitional vertebrae
- Case 28 Subtle injuries in ankylotic spine disorders
- Case 29 Spinal dural arteriovenous fistula
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Summary
Imaging description
Open mouth odontoid radiographs or cervical spine CT demonstrate asymmetric position of the dens between the lateral masses of C1 [1]. The C1 lateral mass contralateral to the direction of head rotation is subluxed anteriorly relative to the C2 lateral mass, while the ipsilateral C1 lateral mass might be posteriorly displaced. This asymmetry can be normal during head rotation, and is very frequently encountered on imaging. If, however, the asymmetric relationship persists when the head is then turned to the contralateral side, atlantoaxial rotatory fixation (AARF) is diagnosed.
Importance
At our institution, far more trauma patients are transferred from outside institutions for further evaluation for AARF than are ultimately diagnosed with it. Differentiation between AARF and acute torticollis, however, is important because torticollis responds to analgesics and conservative management, while AARF requires reduction. Furthermore, reduction has been more successful when performed early in the course of the condition.
- Type
- Chapter
- Information
- Pearls and Pitfalls in Emergency RadiologyVariants and Other Difficult Diagnoses, pp. 72 - 74Publisher: Cambridge University PressPrint publication year: 2013