SPN-003 · October 12, 2026 · Spine · Intermediate

Clearing the Cervical Collar After a Negative CT

A missed unstable neck injury can leave a patient quadriplegic, and a collar left on for days after a negative scan causes pressure ulcers, raised intracranial pressure and airway trouble.

Key terminology

Spinous processes
This bony ridge points backward from each vertebra and is the bump felt down the back of the neck. Pain when pressing it is midline tenderness.
Distracting injury
This painful injury elsewhere, such as a long bone fracture, can mask neck pain. Its presence means the neck exam cannot be trusted.
Obtunded
This patient cannot give a reliable neck exam due to head injury, sedation, intubation or intoxication. Clearance then rests on imaging alone.
High-quality CT
This scan of the cervical spine uses thin axial slices with sagittal and coronal reformats. It is the standard EAST uses to clear the collar.
Central cord syndrome
This incomplete spinal cord injury weakens the arms more than the legs. It typically follows a neck hyperextension injury in an older patient with spondylosis.
Unstable injury
This injury can shift under normal load and damage the spinal cord. It needs surgery, a halo or a rigid brace.
Flexion-extension radiographs
These lateral films are taken with the neck bent forward and back to look for abnormal motion. They are no longer used for acute clearance.

Takeaways

  1. An alert, sober patient with no midline tenderness, no neuro deficit and no distracting injury needs no C-spine imaging. Those 5 findings are the NEXUS low-risk criteria, and midline tenderness means pain on pressing the spinous processes. In 34,069 patients NEXUS missed only 2 clinically significant injuries (sensitivity 99.6%). (Hoffman et al, N Engl J Med 2000;343:94-99, PMID 10891516).
  2. CT is the first study when a trauma patient needs C-spine imaging. Pooled sensitivity was 98% for CT and 52% for plain radiographs. An alert patient with midline tenderness, a negative CT and no deficit can have the collar removed without MRI. Flexion-extension radiographs no longer have a role in acute clearance. (Holmes and Akkinepalli, J Trauma 2005;58:902-905, PMID 15920400; Lukins et al, ANZ J Surg 2015;85:917-922, PMID 26177678).
  3. In the obtunded adult, EAST recommends removing the collar after a negative high-quality CT alone. High-quality means axial slices under 3 mm. Across 11 studies (1718 patients) no unstable injury turned up after a negative high-quality CT, although up to 9% had a stable injury. The recommendation is conditional and rests on very low-quality evidence. (Patel et al, J Trauma Acute Care Surg 2015;78:430-441, PMID 25757133).
  4. A focal neurologic deficit after a negative CT still needs an MRI. In a prospective trial of 10,276 patients, CT missed only 3 clinically significant injuries, and all 3 had a deficit consistent with central cord syndrome. In 83 obtunded patients, 4 had a negative CT and cord signal change on MRI, and all 4 went on to decompression. (Inaba et al, J Trauma Acute Care Surg 2016;81:1122-1130, PMID 27438681; Tan et al, Clin Neurol Neurosurg 2014;120:23-26, PMID 24731570).
  5. The Canadian C-Spine Rule sends every adult 65 or older to imaging, and NEXUS is less reliable in older patients. Age ≥65, a dangerous mechanism or paresthesias in the extremities mandate imaging under the CCR. Head to head in 8283 alert patients, the CCR missed 1 injury and NEXUS missed 16. NEXUS sensitivity fell to 65.9% in severely injured adults ≥65. (Stiell et al, N Engl J Med 2003;349:2510-2518, PMID 14695411; Goode et al, Am Surg 2014;80:182-184, PMID 24480220).
  6. Modern CT alone detects nearly every unstable cervical injury in obtunded and intubated patients. A meta-analysis of 17 studies (14,327 patients) found sensitivity and specificity both >99.9% for injuries needing surgery or a brace. In the prospective trial of 10,276 patients, CT had a negative predictive value of 99.97%. (Panczykowski et al, J Neurosurg 2011;115:541-549, PMID 21619408; Inaba et al, J Trauma Acute Care Surg 2016;81:1122-1130, PMID 27438681).
  7. Neurosurgical guidelines still allow an MRI or a longer collar before clearing the obtunded patient. The 2013 AANS/CNS guideline offers options (keep the collar, clear after a normal MRI, or leave it to the treating physician) rather than one rule. An MRI meta-analysis of 5286 patients with a negative CT found only 11 injuries judged unstable on review. (Ryken et al, Neurosurgery 2013;72 Suppl 2:54-72, PMID 23417179; Malhotra et al, Eur Radiol 2017;27:1148-1160, PMID 27334017).
  8. A collar left on after a negative scan does harm. Prolonged hard collars had a pooled pressure ulcer prevalence of 7%. In patients with traumatic brain injury, applying a collar raised intracranial pressure by about 4.4 mmHg. Collars also make airway and central line management harder. (Brannigan et al, Global Spine J 2022;12:1968-1978, PMID 35333123; Núñez-Patiño et al, Neurocrit Care 2020;32:469-477, PMID 31190321; Patel et al, J Trauma Acute Care Surg 2015;78:430-441, PMID 25757133).

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