Hx: MVA, neck pain
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Answer: Unilateral Facet Dislocation
Normal L & R superior articular facets overlap/aligned to the C6-C7 where 1 is shifted anterior(red dash)
-Ant & post vertebral lines (green) ?ok
-Spinolaminar line (orange)=broken
-Poseriort spinous line (purple) = gap
Perched facet = subluxed joint with tip of inferior facet resting on tip of super facet of lower body
Dislocated/jumped/locked facet = complete dislocation with inferior tip ANTERIOR to superior facet of lower body (thus “locked”)
Get the CT and ALWAYS look for the fracture!
Unilateral jumped facets can be tough on X-ray as the vert body doesn’t have to displace much (vert lines ok).
ALWAYS look at spinolaminar & posterior spinous lines!
Facets = “shingles on a roof"
Any abrupt change/rotation should be concerning!
For completeness, here is a bilateral facet dislocation.
ALL spinal lines disrupted. No rotation. Both inferior facets jumped and locked anterior to the superior facets of the lower body.
- MRI=diffuse ligamentous injury
- neurologically devastating