CT scan of the cervical spine shows a minimally displaced fracture of the right C5 lamina, with slight subluxation of the right C5-C6 facet joint. On further examination, the patient has mild weakness of right wrist extension and loss of pinprick sensation in the right thumb. Which of the following additional studies should be obtained?

Question

CT scan of the cervical spine shows a minimally displaced fracture of the right C5 lamina, with slight subluxation of the right C5-C6 facet joint.  On further examination, the patient has mild weakness of right wrist extension and loss of pinprick sensation in the right thumb.  Which of the following additional studies should be obtained?

Quizplus · Accepted Answer

This patient's CT scan reveals a C5 right lamina fracture, a fracture that can occur with neck hyperextension (eg, head impacting an expanded airbag). If the fracture causes osteoligamentous injury to the adjacent facet (eg, right C5-C6 facet joint), unilateral facet joint subluxation may occur. The subluxation can compress the associated spinal nerve root and cause monoradiculopathy, as seen in this patient with signs of C6 radiculopathy (eg, weak wrist extension, thumb sensory loss). lamina The presence of a single vertebral fracture (especially cervical) in a patient with blunt trauma is an indication to image the entire spine because the risk of a second, noncontiguous vertebral fracture is as high as 20%. Other indications for imaging the thoracolumbar spine (TLS) include focal pain or signs of injury (eg, bruising, step-off), corresponding neurologic deficit, altered mental status or distracting injury, and high-energy mechanism (eg, high-speed motor vehicle collision, fall ≥3 m [10 ft]). Because CT scan is more sensitive and accurate than plain radiography for diagnosing TLS injury, it is the screening modality of choice in patients with any of the above indications. (Choice A) Because the esophagus lies anterior to the cervical spinal column, cervical spine injury can sometimes cause esophageal perforation (which barium esophagography can evaluate). However, this complication is very rare (<1%) compared to concomitant TLS fracture (~20%). Routine screening is not performed, but evaluation would be appropriate if the patient later develops dysphagia, odynophagia, and/or subcutaneous emphysema. (Choice B) Cervical trauma can rarely injure the carotid arteries, causing dissection or occlusion (which might be seen on carotid ultrasound). However, symptoms related to dissection or occlusion (eg, hemiparesis, headache, Horner syndrome) would be expected. This patient's symptoms are most consistent with C6 radiculopathy. (Choice D) A nerve conduction study is commonly performed to localize the site of peripheral nerve injury/compression (eg, carpal tunnel), usually in order to direct treatment (eg, carpal tunnel release). This patient's symptoms are more consistent with right C6 radiculopathy (ie, nerve root compression) than with peripheral neuropathy and are already explained by the right C5-C6 facet joint subluxation. Educational objective: The presence of a single vertebral fracture in a patient with blunt trauma is an indication to image the entire spine. CT scan is the screening modality of choice because of its sensitivity and accuracy. References: Screening for thoracolumbar spinal injuries in blunt trauma: an Eastern Association for the Surgery of Trauma practice management guideline. (http://www.ncbi.nlm.nih.gov/pubmed/23114489) Blunt thoracolumbar-spine trauma evaluation in the emergency department: a meta-analysis of diagnostic accuracy for history, physical examination, and imaging. (http://www.ncbi.nlm.nih.gov/pubmed/30598296)

CT Scan of the Cervical Spine Shows a Minimally Displaced