- Cervical lateral mass fracture separation
- Perched facet joint
- Synovial cysts of the facet joints
The correct diagnosis is perched facet joint, a vertebral facet joint whose inferior articular process appears to sit “perched” on the ipsilateral superior articular process of the vertebra below. The oblique view shows a lack of overlap of the c6 and c7 facets and anterolisthesis of c6 on c7. A step-off is noted along the posterior cervical line at c6 and widened interspinous space posteriorly. Additionally, the x-rays reveal significant degenerative changes with multilevel disc space narrowing, end plate spurring, and loss of height of c5 and c6 (likely chronic).
Learnings/What to Look for
- Any further anterior subluxation of the perched facet joint will result in dislocation, with one facet “jumping” over the other and becoming locked in this position
- Complications include spinal cord injury, especially with bilateral involvement or, in the setting of canal stenosis, vertebral artery injury, including dissection, thrombosis, and stroke
- Diagnosis can be confirmed with radiographs, CT scan or MRI
Pearls for Urgent Care Management
- Treatment usually involves closed or open reduction followed by surgical stabilization
- Sambhaji CJ. Perched facet joint. Radiopaedia. Available at: https://radiopaedia.org/cases/5948. Accessed August 2, 2023.
- Chieng R. Perched facet joint. Radiopaedia. Available at: https://radiopaedia.org/articles/5940. Accessed August 2, 2023.
- Forsthoefel C, Moore DW. Cervical facet dislocations & fractures. Ortho Bullets. Available at: https://www.orthobullets.com/spine/2064/cervical-facet-dislocations-and-fractures. Accessed August 2, 2023.