Locked facet joint

Locked facet joint is a type of facet joint dislocation that results from jumping of the inferior articular process over the superior articular process of the vertebra below and becomes locked in the position.

It can be unilateral or bilateral.

Radiographic features

Plain radiograph

The tip of inferior articular process is seen anterior to the superior articular process of the vertebra below.


Shows the radiographic findings in more details. The naked facet sign (or reverse hamburger bun sign) sometimes can be seen on axial scan.


Can show ligamentous injuries apart from the dislocation.

Spinal trauma
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Article information

rID: 35404
Section: Gamuts, Signs
Tag: cases
Synonyms or Alternate Spellings:
  • Jumped facet
  • Locked facet

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Cases and figures

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    Case 1
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    Left facet joints
    Case 2
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