NEXUS Criteria for Cervical Spine Imaging After Blunt Trauma
Cervical spine imaging can be safely omitted in blunt trauma patients who meet ALL five NEXUS low-risk criteria: no midline cervical tenderness, no focal neurologic deficit, normal alertness, no intoxication, and no painful distracting injury 1.
The Five NEXUS Criteria
A patient is considered LOW RISK and does NOT require cervical spine imaging if ALL of the following are absent:
- Midline cervical tenderness - No pain on palpation of the posterior midline cervical spine
- Focal neurologic deficit - No motor or sensory deficits on examination
- Altered level of alertness - Patient is awake, alert, and oriented (GCS 15)
- Intoxication - No evidence of alcohol or drug intoxication
- Painful distracting injury - No other severely painful injury that might distract from cervical pain
If ANY single criterion is positive, cervical spine imaging IS indicated 1, 2.
Performance Characteristics and Evidence Strength
The NEXUS criteria were validated in a landmark prospective multicenter study of 34,069 blunt trauma patients, demonstrating:
- Sensitivity: 99.6% (95% CI: 98.6%-100%)
- Negative predictive value: 99.9% (95% CI: 99.8%-100%)
- Specificity: 12.9% (intentionally low to maximize safety)
This means the criteria successfully identify virtually all clinically significant cervical spine injuries while allowing approximately 37% of patients to avoid unnecessary imaging 1, 2.
Critical Age-Related Caveat
The NEXUS criteria have reduced sensitivity in elderly patients (>65 years old), dropping to 66-89% 1. For this population, maintain a lower threshold for imaging. Some experts recommend adding facial/head injury and any deviation from baseline mental status as additional criteria to restore 100% sensitivity in elderly patients 1.
Imaging Modality When Criteria Are Positive
When NEXUS criteria indicate imaging is needed:
- CT is the first-line modality - multidetector CT has replaced plain radiography due to superior accuracy and speed 1
- MRI should follow in non-examinable or NEXUS-positive patients with negative CT - 28% of CT-negative patients had injuries detected on MRI, with 6.8% requiring operative intervention 3
- Plain radiography is no longer recommended except where CT is unavailable 4
Common Pitfalls to Avoid
- Do not apply NEXUS to obtunded or unconscious patients - these patients automatically fail the "normal alertness" criterion and require imaging
- Do not skip imaging in elderly patients based on NEXUS alone - consider additional risk factors like facial trauma or any mental status change
- Do not remove cervical collars based on negative CT alone in NEXUS-positive patients - obtain confirmatory MRI, as 23% of "stable" CT findings were reclassified as unstable on MRI 3
- Intoxication includes both alcohol and drugs - err on the side of imaging if there is any question of substance use
Clinical Implementation
The NEXUS criteria substantially reduce imaging overuse while maintaining exceptional safety. A prospective Western Trauma Association trial confirmed 98.5% sensitivity and 99.97% negative predictive value when using CT 1. Patients meeting all five low-risk criteria can have cervical collars removed without imaging, significantly reducing iatrogenic complications from prolonged immobilization, emergency department time, and healthcare costs 1.