NEXUS C-Spine Calculator — Cervical Spine Injury Clearance in Trauma

How to Use This Calculator

1. Assess the patient for each of the 5 NEXUS low-risk criteria.
2. Select Present or Absent for each criterion.
3. If all 5 criteria are absent (score = 0), C-spine imaging is not required.
4. Use the NEXUS vs CCR tab to compare decisions between the two rules.
5. Use the Criteria Definitions tab for clinical definitions of each criterion.

Formula

Example

Frequently Asked Questions

• What are the NEXUS criteria for cervical spine clearance? ▼
  The NEXUS (National Emergency X-Radiography Utilisation Study) low-risk criteria are five clinical factors used to determine whether a blunt trauma patient requires cervical spine imaging. All five criteria must be absent for C-spine imaging to be safely omitted. The criteria are: (1) no focal neurological deficit attributable to the cervical spinal cord or nerve roots; (2) no midline cervical spine tenderness to palpation of the posterior spinous processes from occiput to T1 — paravertebral tenderness alone does not count; (3) normal level of alertness (GCS 15, oriented, no delayed responses); (4) no evidence of intoxication with alcohol or other CNS-affecting substances; and (5) no distracting injury — a painful injury that may divert attention from cervical spine pain assessment. If any single criterion is present, cervical spine imaging is required before collar removal.
• What is the sensitivity and specificity of the NEXUS criteria? ▼
  The NEXUS criteria were validated in the landmark 2000 study by Hoffman et al. published in the New England Journal of Medicine. In 34,069 blunt trauma patients, the criteria identified all but 8 of 818 clinically significant cervical spine injuries, yielding a sensitivity of 99.0% and a negative predictive value of 99.8%. Specificity was 12.9%, meaning many patients who would test negative for C-spine injury were still imaged — highlighting that NEXUS is a rule-out tool with high sensitivity rather than a specific diagnostic test. The 8 missed injuries were predominantly in elderly patients and those with minor mechanisms. The NEXUS criteria are most reliable in alert, sober adult patients with a clear mechanism of injury.
• How does NEXUS compare to the Canadian C-Spine Rule? ▼
  Both NEXUS and the Canadian C-Spine Rule (CCR) are validated clinical decision tools for C-spine clearance, but the CCR has higher specificity. The CCR, developed by Stiell et al. and published in JAMA in 2001, uses a three-step algorithm: first, identify any high-risk factors mandating imaging (dangerous mechanism, paraesthesias, age 65 or above); second, if no high-risk factor, identify any low-risk factor allowing safe range-of-motion assessment; third, assess whether the patient can actively rotate the neck 45 degrees bilaterally. CCR sensitivity is approximately 99.4% and specificity 45.1%, compared to NEXUS sensitivity 99.0% and specificity 12.9%. In a direct comparison by Stiell et al. in NEJM 2003, CCR was more sensitive and specific than NEXUS. CCR is recommended in Canada; both tools are used in the USA depending on institutional preference.
• Can NEXUS criteria be used in elderly patients or children? ▼
  NEXUS criteria were validated primarily in adults and have recognised limitations in specific populations. In elderly patients (age 65 or above), the criteria have been shown to have lower sensitivity, with a higher rate of missed injuries — particularly odontoid (C2) fractures, which can occur with minimal mechanism and may not cause midline tenderness or neurological symptoms. Several studies have suggested that elderly patients with a significant mechanism of injury should receive CT imaging regardless of NEXUS result. In children, NEXUS was studied in a subset of the original NEXUS cohort and showed acceptable performance, but paediatric C-spine injuries have unique patterns (upper cervical, SCIWORA — spinal cord injury without radiographic abnormality). Most paediatric trauma guidelines recommend applying NEXUS with caution and having a lower threshold for imaging in very young children.
• What imaging modality is preferred for C-spine clearance if NEXUS criteria are present? ▼
  If any NEXUS criterion is present, CT of the cervical spine is the preferred imaging modality in most current guidelines (ACEP, EAST, ATLS). CT provides superior sensitivity for bony C-spine injuries compared to plain radiographs — a multicentre study by Mathen et al. found CT sensitivity at approximately 97–99% versus 52% for three-view plain films. Plain radiographs (AP, lateral, and open-mouth odontoid view) may be acceptable in select low-risk patients where CT is unavailable, but are no longer first-line in major trauma centres. If neurological deficit is present, MRI is required in addition to or instead of CT to evaluate spinal cord compression, ligamentous injury, and epidural haematoma that may not be visible on CT. The collar should be maintained until imaging is reviewed and a physician has cleared the spine clinically and radiographically.

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