A 46-year-old man fell four steps, striking his neck and having associated neck pain and discomfort. He was evaluated at a local emergency department and reported no neurological deficit but focal mid cervical tenderness. Radiographs and computed tomography (CT) scan were “negative” for cervical spine fracture, dislocation or pre-vertebral soft tissue swelling. He was discharged home in a cervical collar with a scheduled outpatient follow-up. Over the proceeding hours neurologic deterioration occurred, including hand and lower limb weakness with the inability to urinate. The patient returned to the local emergency room and was transferred to a tertiary care hospital where examination revealed C5ASIAB deficits. Repeat high resolution CT scan of the cervical spine with reformatted images was unremarkable for osseous fractures except some loss of definition in the posterior cervical musculature. Emergency magnetic resonance imaging MRI revealed a subluxation of C5/6 right facet (not evident on CT) with disruption of the posterior longitudinal ligament, ligamentum flavum, and disc space with abnormal T2 weighted spinal cord hyperintense signal at C5/6. He underwent emergency C5–C6 anterior and posterior decompression and fusion. One week later an examination showed improved C5ASIAD. This case reveals the difficulty of assessing the cervical spine for instability and potential limitations of current management schemes.