Computed tomography-occult discoligamentous instability following blunt cervical spine trauma

Plain CT is routinely ordered following blunt trauma of the cervical spine, and performs well in the exclusion of significant bony injuries. MRI is reserved for cases of suspected neural or posterior ligamentous compromise, and when other imaging modalities are contraindicated. There are patients however, with unremarkable radiology, and without suggestive clinical features, who are later found to have significant discoligamentous instability. In this report, we present two such cases. In both instances, worsening neurological symptoms prompted follow-up imaging, that demonstrated interval development of sub-axial cervical spondylolisthesis, requiring surgery and instrumentation. We identify and discuss radiological features that may be associated with occult discoligamentous injury, and highlight them as avenues for future research. These may prove useful in stratifying at-risk patients for further imaging in the acute setting.