Perched facet joint is a vertebral facet joint whose inferior articular process appears to sit 'perched' on the ipsilateral superior articular process of the vertebra below.
Any further anterior subluxation will result in dislocation, with one facet "jumping" over the other and becoming locked in this position (see jumped facet joint).
Unilateral perched facet results from flexion-rotation force. Perched bilateral facets are also possible.
- malalignment of the lateral masses
- the tips of adjacent facets touch each other i.e. inferior articular process of a vertebra appears to sit 'perched' on the superior articular process of the vertebra below
- distracted facet with uncovering of the articular surface
- spinal cord injury, especially with bilateral involvement, or in the setting of canal stenosis
- vertebral artery injury, e.g. dissection, thrombosis
- 1. Yetkin Z, Osborn AG, Giles DS et-al. Uncovertebral and facet joint dislocations in cervical articular pillar fractures: CT evaluation. AJNR Am J Neuroradiol. 6 (4): 633-7. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 2. Lingawi SS. The naked facet sign. Radiology. 2001;219 (2): 366-7. Radiology (full text) - Pubmed citation
- 3. Stäbler A, Eck J, Penning R et-al. Cervical spine: postmortem assessment of accident injuries--comparison of radiographic, MR imaging, anatomic, and pathologic findings. Radiology. 2001;221 (2): 340-6. doi:10.1148/radiol.2212010336 - Pubmed citation
- 4. Gharib A, Postel G, Mirza S et-al. A thoracic spine translation injury with lateral facet dislocation. AJR Am J Roentgenol. 2002;178 (6): 1450. AJR Am J Roentgenol (full text) - Pubmed citation
- 5. Greenspan A. Orthopedic imaging, a practical approach. Lippincott Williams & Wilkins. (2004) ISBN:0781750067. Read it at Google Books - Find it at Amazon
- fractures by location
- cervical spine fracture classification systems
- thoracolumbar spinal fracture classification systems
- three column concept of spinal fractures (Denis classification)
- classification of sacral fractures
- facet dislocation