What injury is present?
Bilateral dislocated (locked) facets with anterolisthesis of C5 on C6 and central spinal canal narrowing.
What sign is present of locked facets?
The "reverse hamburger bun" sign - on axial slices the normal facet joint looks somewhat like a hamburger, but in locked or dislocated facets the two curved surfaces abut each other hence the name.
There is approximately 50% subluxation of C5 on C6, with intervertebral disc space narrowing.
This is associated with bilateral dislocated facets joints at this level, in association with abnormal widening of the interspinous space. No fracture is identified. There is severe central canal stenosis at this level, with significant impingement of the cervical cord.
There is abnormal anterior vertebral soft tissue swelling centered at this level.
Conclusion
The findings are consistent with a severe hyperflexion injury, with bilateral locked facets at the C5/C6 level.