Imaging of the Cervical Spine > Fractures > Unilat. Dislocation

Unilateral Facet Dislocation

Description: facet joint dislocation and rupture of the apophyseal joint ligaments resulting from rotatory injury of the cervical vertebrae.

Mechanism: simultaneous flexion and rotation

Radiographic features: (best seen on lateral or oblique views)

1. Anterior dislocation of affected vertebral body by less than half of the vertebral body AP diameter.
2. Discordant rotation above and below involved level.
3. Facet within intervertebral foramen on oblique view.
4. Widening of the disk space.
5. "Bow tie" or "bat wing" appearance of the overriding locked facets.

Stability: stable