A bilateral facet dislocation is an unstable flexion distraction type of dislocation of the cervical spine, often a result of buckling force. Occasionally, the bilateral facet dislocation has been named a 'doubly-locked' vertebral injury giving the impression of stability. However, due to complete ligamentous disruption, this is, in fact, an unstable injury 1.
Pathology
Mechanism
A bilateral facet dislocation was historically thought to result from hyperflexion, however, since 2010s it is thought that a buckling force is more likely to be the primary cause 2.
Radiographic features
loss of apposition at facet joint: bilateral facet joints may be perched or locked
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anterolisthesis can be more than 50%
if there is a lesser amount of displacement one of the facet joints may be intact (unilateral facet joint dislocation)
increased interspinous distance