Decides whether a patient with blunt trauma needs cervical spine imaging, from five bedside criteria.
Result
Mark each of the five criteria as absent or present.
Sources
5 studies
5
studies
1,308
citations
176
PubMed papers
Evidence
Known limitations
In 34,069 patients, the criteria were 99.0% sensitive (95% CI 98.0% to 99.6%) for cervical spine injury, with a negative predictive value of 99.8% and a specificity of 12.9%; for clinically significant injury the sensitivity was 99.6%.
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 1,308 times
In 8,283 alert, stable patients, the Canadian C-spine rule was more sensitive (99.4% vs 90.7%) and more specific (45.1% vs 36.8%) than the NEXUS criteria, and would have reduced radiography (55.9% vs 66.6%).
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 647 times
Of 3,065 NEXUS patients under 18, 30 had a cervical spine injury and the criteria identified all of them (sensitivity 100%, 95% CI 87.8% to 100%). Only 4 injured children were under 9 and none under 2, so the authors advise caution in infants and toddlers.
Pediatrics: Journal Metrics Score 4.7, Q1 · cited 408 times
A systematic review of NEXUS in older patients found sensitivity ranging from 66% to 100% across studies, lower in some than in the original NEXUS cohort.
Among 2,943 patients aged 65 or older, injuries were twice as common as in younger patients and odontoid fractures more frequent; the criteria were 100% sensitive (95% CI 97.1% to 100%) for clinically significant injury.
Ann Emerg Med: Journal Metrics Score 0.8, Q3 · cited 102 times
The original paper has been cited 1,308 times, and 176 PubMed articles mention the NEXUS criteria in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 14, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
Imaging indicated · Low risk · Before applying
Immobilize and image. Clear clinically. Check the rule fits.
Next steps
Avoid common errors
5 common errors to avoid
and 3 more
When the criteria mislead
1Older adults
Low-energy falls cause odontoid fractures in older people. NEXUS has no age criterion; the Canadian rule images everyone aged 65 or older.
2Reliable examination
Intoxication, head injury, drugs given for pain and language barriers make tenderness and neurological findings unreliable.
3Distraction is subjective
NEXUS gave no exact definition of a distracting injury, and clinicians apply it differently.
4New symptoms
Paresthesia or weakness that appears later needs imaging, even if the first assessment was low risk.
5Young children
Few children under 2 were studied; use pediatric guidance and clinical judgment.
Formula
Imaging is not needed if there is no midline tenderness, focal deficit, altered alertness, intoxication or painful distracting injury.
Imaging is not needed if there is no midline tenderness, focal deficit, altered alertness, intoxication or painful distracting injury.
Criteria and result
| Criterion | Definition |
|---|---|
| Midline posterior cervical spine tenderness | Pain on palpation of the posterior midline of the neck, from the nuchal ridge to the prominence of the first thoracic vertebra, or pain on palpation of any cervical spinous process. |
| Focal neurological deficit | Any focal neurological finding on motor or sensory examination. (Not part of NEXUS: paraesthesia reported by the patient is a high-risk factor in the Canadian C-spine rule, and new or transient neurological symptoms are a reason to image whatever the NEXUS result.) |
| Altered level of alertness | GCS 14 or less; disorientation to person, place, time or events; inability to remember three objects at 5 minutes; delayed or inappropriate response to external stimuli; or any other finding of altered alertness. |
| Evidence of intoxication | A recent history, from the patient or an observer, of intoxication or an intoxicating ingestion; signs of intoxication on examination (smell of alcohol, slurred speech, ataxia, other cerebellar signs), behaviour suggesting intoxication, or a positive test for alcohol or drugs that affect alertness. |
| Painful distracting injury | Any injury painful enough to distract from a neck injury: for example a long-bone fracture, a visceral injury needing surgical consultation, a large laceration, degloving or crush injury, large burns, or any injury causing acute functional impairment. |
| Result | Criteria | Meaning |
|---|---|---|
| Low risk: no imaging needed | all five absent | None of the five criteria is present, so cervical spine imaging is not needed by NEXUS. In the validation study, 8 of 818 patients with an injury met all five low-risk criteria; 2 of the 8 had a clinically significant injury. |
| Imaging indicated | any one present | At least one criterion is present, so NEXUS cannot rule out a cervical spine injury. Keep the cervical spine protected and image it; CT is the usual first test in adults. |
Hoffman 2000
Stiell 2003
Not for penetrating trauma
Test cases
3 published cases, each also a test case
3 published cases; the calculator reproduces every result.
Worked examples
A 73-year-old man, a belted front-seat passenger, was in a low-speed collision with a stationary car. He had a forehead laceration, no loss of consciousness, full recall, no cervical spine tenderness and no neurological deficit; the authors scored NEXUS as 0 and he was sent home. He came back the next day with tingling in the left hand, and CT showed fractures at C4 and C7.
“the National Emergency X-ray Utilization Study (NEXUS) score was determined to be 0”
By the authors’ assessment NEXUS was negative and still missed the fractures. At his return the examination was normal; the authors counted his new paraesthesia as a NEXUS criterion, though NEXUS defines a deficit as an examination finding. At 73 he would have needed imaging under the Canadian C-spine rule, which images everyone aged 65 or older and anyone with paraesthesia; the authors note that UK guidance prefers that rule.
Entered as: Midline posterior cervical spine tenderness: Absent; Focal neurological deficit: Absent; Altered level of alertness: Absent; Evidence of intoxication: Absent; Painful distracting injury: Absent.
Source: Mahmood A et al., Cureus 2025 (PubMed · Free full text · DOI)
A 17-year-old footballer lost movement and sensation in all four limbs after a helmet-to-helmet collision. Both recovered over about 10 minutes, but the on-field examination then found tenderness over the sixth cervical vertebra, and he was immobilized and taken to the emergency department. CT and flexion–extension films were normal and he was discharged with a diagnosis of a ‘stinger’; an MRI three days later showed congenital canal narrowing at C4 with spinal cord contusions at C3–C4, and he was advised to stop contact sports.
“on-site examination demonstrated sixth cervical (C6) vertebral tenderness to palpation”
Midline tenderness alone makes him not low risk. His neurological signs had resolved before the examination, so only tenderness is entered; a history of transient quadriplegia is a reason to image on its own. A normal CT did not exclude the cord injury.
Entered as: Midline posterior cervical spine tenderness: Present; Focal neurological deficit: Absent; Altered level of alertness: Absent; Evidence of intoxication: Absent; Painful distracting injury: Absent.
Source: Jabola R et al., Clin Pract Cases Emerg Med 2021 (PubMed · Free full text · DOI)
An 11-year-old girl had neck pain and immediate weakness of the right arm and leg after her father fell on her neck during play. A local hospital found a normal head CT and treated her for Guillain-Barré syndrome; 3 days later, at the referral hospital, there was midline tenderness at the back of the upper neck and reduced strength and sensation on the right. Plain X-rays were normal, but CT and MRI showed a type II odontoid fracture with cord oedema, treated by decompression and a modified Gallie C1–C2 fusion.
“there was a midline tenderness on the back of her upper neck”
Two criteria are present. The authors describe NEXUS as an adult tool and point to the PECARN criteria for children; a pediatric NEXUS analysis found the criteria 100% sensitive in children, though with few injuries in young children. Normal plain films did not exclude the fracture.
Entered as: Midline posterior cervical spine tenderness: Present; Focal neurological deficit: Present; Altered level of alertness: Absent; Evidence of intoxication: Absent; Painful distracting injury: Absent.
Source: Sakti YM et al., Int J Surg Case Rep 2025 (PubMed · Free full text · DOI)
FAQ
6 questions and answers
and 4 more answers
Questions
No midline cervical spine tenderness, no focal neurological deficit, normal alertness, no evidence of intoxication, and no painful distracting injury. A patient who meets all five is low risk and does not need cervical spine imaging.
In the validation study of 34,069 patients, the criteria were 99.0% sensitive for any cervical spine injury and 99.6% sensitive for clinically significant injury, but only 12.9% specific. In a Canadian head-to-head study of alert, stable adults their sensitivity was lower, 90.7%.
For alert, stable adults the Canadian C-spine rule was more sensitive (99.4% vs 90.7%) and more specific (45.1% vs 36.8%) in a study of 8,283 patients, and would have led to fewer X-rays. UK guidance (NICE) uses the Canadian rule for adults. NEXUS is simpler, needs no range-of-motion test, and has been studied in children, whom the Canadian rule did not include (it was derived in patients aged 16 or older).
The NEXUS data included 3,065 patients under 18, and the criteria identified all 30 with an injury. But only 88 were under 2 years, only 4 of the injured children were under 9 and none was under 2, so the authors advise caution in infants and toddlers.
In 2,943 patients aged 65 or older from the NEXUS cohort, the criteria missed no clinically significant injury. Later studies were less reassuring: a systematic review found sensitivity in older patients ranging from 66% to 100%. Older patients have more injuries, especially odontoid fractures, so many clinicians image them after low-energy falls; the Canadian rule images everyone aged 65 or older.
NEXUS gave no exact definition. Examples are a long-bone fracture, a visceral injury needing surgical review, a large laceration, degloving or crush injury, large burns, or any injury causing acute functional impairment, or any injury the clinician thinks may stop the patient noticing neck pain.
Further reading
9 references with PubMed and DOI links
9
references
3
free full text
From Hoffman JR et al., N Engl J Med 2000 to the newest case reports.
References
clinical grade of aneurysmal subarachnoid hemorrhage, I to V.
total calcium adjusted for albumin, in mg/dL or mmol/L.
stroke severity from 15 bedside items, 0 to 42.
MAP from systolic and diastolic pressure, against the 65 mm Hg target.
eye, verbal and motor scores for preverbal children, 3 to 15.
oxygenation ratio with the Berlin ARDS severity ranges.
serum sodium corrected for high glucose, Katz or Hillier factor.
sodium − (chloride + bicarbonate), with the albumin-corrected gap.
urea nitrogen to creatinine ratio, in US or SI units.
estimated creatinine clearance with actual, ideal or adjusted weight.
cardiac output and index from oxygen consumption and saturations.
ANC from the white cell count, neutrophils and bands.
insulin resistance from fasting glucose and insulin, in US or SI units.
FENa from plasma and urine sodium and creatinine: prerenal, indeterminate or tubular pattern.
three-item stroke severity screen for large vessel occlusion, 0 to 4.
water deficit in hypernatremia from sodium, weight and body water.
expected PaCO2 in metabolic acidosis, 1.5 × HCO3 + 8 ± 2.
corrected QT interval by Bazett, Fridericia, Framingham or Hodges.
head CT decision rule for children with minor head trauma.
blood loss before hemoglobin or hematocrit reaches a chosen lowest value.
eye, verbal and motor response, 3 to 15, with GCS-Pupils.
Devine ideal body weight and adjusted weight from height and sex.
cuffed and uncuffed tube size and oral depth by age.
calculated osmolality, osmolal gap and ethanol correction.
severity of alcohol-associated hepatitis from prothrombin time and bilirubin.
MELD, MELD-Na and MELD 3.0 for chronic liver disease.
early stroke risk after a transient ischemic attack.
prognosis from a Bruce protocol exercise test.
alveolar–arterial oxygen gradient from a blood gas.
whether an adult with minor head injury needs CT.
risk of advanced liver fibrosis from age, AST, ALT and platelets.
Which published the NEXUS methods and the geriatric analysis, with its current metrics.
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 14, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.