Atlas (type 3b subtype 1) and axis (Anderson and D'Alonzo type 3, Roy-Camille type 2) fractures

Comminuted fracture of C1 involving the anterior arch, left lateral mass, and the posterior elements. Small fracture of the posterior arch of C1 is also noted. Resultant incongruent articulation of the lateral mass of C1/C2.

Posteriorly slanted oblique fracture of the odontoid process at the base, with posterior angulation of the dens and retropulsion. Moderate narrowing of the central canal at this level due to angulation of the odontoid process and suspected ligamentous thickening/ hematoma. Moderate degree of central spinal canal stenosis.

Prior surgical fusion at C5/C6, with suspected disc material at this level.
Advanced bilateral facet joint degenerations are present at multiple levels. There is severe bilateral C4/C5 neural foraminal stenosis with suspected impingement of the C5 nerve root.
No abnormal prevertebral soft tissue swelling seen.
Dystrophic calcification over the ligamentum nuchae is thought to reflect sequelae of previous trauma.
Mild stranding along the left sternocleidomastoid muscle noted.

IMPRESSION

• Comminuted fracture of the C1
• Fracture through the base of the odontoid process, with sharp dorsal angulation of the odontoid process causing moderate canal stenosis at this level.
• Subluxation of the bilateral C1/C2 lateral masses.

Jefferson multi-part fractures involving both the anterior and posterior C1 arches demonstrated with lateral displacement of the lateral mass of C1 relative to C2 (more on the right). Disrupted transverse atlantal ligament.

Mildly displaced type 3 oblique fracture of the dens with extension into the base and retrolisthesis of 5 mm.

Posterior displacement of the posterior longitudinal ligament demonstrated. No epidural hematoma. Severe narrowing of the upper cervical canal with compression of the upper cervical spinal cord with T2 hyperintense cord signal from the foramen magnum to C2 vertebral level for a length of 21 mm.

Prevertebral edema from base of skull to C4. Posterior para vertebral edema in the upper cervical region from hyperextension injury.

Intervertebral disc fusion seen at C5 - C6. Old anterior wedge compressions of C5, T1, T2 and T4 showing 20- 30% loss of vertebral body height . Linear cystic areas seen within the spinal cord at C5 - C6 disc level suggesting myelomalacia (larger on the left) - likely longstanding. Degenerative changes of the cervical spine including multilevel facet arthropathy. Carotid and vertebral artery flow voids are patent.

IMPRESSION

• Multi part Jefferson fracture involving anterior and posterior arches of C1 with lateral mass displacement.
• Type 2 dens fracture involving the body of C2 with retrolisthesis.
• Severe upper cervical spinal canal narrowing with cervical cord compression and cord contusion injury/edema.
• Cervical disc fusion at C5 - C6 with likely myelomalacia changes of the spinal cord at this level - likely longstanding.