Canadian C-spine Rule

How it is done

For alert (GCS 15), stable patients aged 16 or over after blunt trauma to the head or neck. The 2001 study excluded patients who were pregnant, had penetrating trauma, acute paralysis, known spinal disease (ankylosing spondylitis, rheumatoid arthritis, spinal stenosis) or previous neck surgery, or were injured more than 48 hours earlier, so the rule has not been tested in them. Three steps. (1) Is there any high-risk factor: age 65 or over; a dangerous mechanism (fall from 0.9 m (3 feet) or more, or from 5 stairs, axial load to the head such as a diving injury, high-speed car crash over 100 km/h, rollover or ejection, motorised recreational vehicle or bicycle collision); or pins and needles in the arms or legs? If yes, image. (2) Is there any low-risk factor that allows range of motion to be tested safely: simple rear-end car crash, sitting in the emergency department, walking at any time since the injury, delayed onset of neck pain, or no midline neck tenderness? If none, image. (3) Can the patient actively turn the neck 45° to the left and to the right? If not, image. If they can, no imaging is needed.

What the studies found

Decision rule for imaging after neck trauma — a rule-out tool. A negative rule means imaging is not needed; a positive rule means 'image', not 'injury present' (LR+ only 1.81). Validation: Stiell 2003, 9 Canadian emergency departments, 8,283 patients, 169 (2.0%) with a clinically important injury. The figures are for the 7,438 patients whose range of motion was assessed; in 845 (10.2%) the doctors did not check range of motion as the rule requires. Counting those patients as rule-positive, sensitivity stayed at 99.4% and specificity was 40.4%. The rule missed 1 important injury; the NEXUS criteria missed 16 in the same patients. Derivation: Stiell 2001, 8,924 adults, sensitivity 100% (95% CI 98–100%), specificity 42.5% (95% CI 40–44%). Developed and validated by the same research group, in emergency departments.

What the numbers mean

• Positive result: barely informative: a positive result changes little.
• Negative result: a strong rule-out: a negative result makes the diagnosis very unlikely.

The ladder: what a result does to your estimate

Calculated from the likelihood ratios above. Read the caution above before relying on these. For any other starting estimate, use the probability calculator.

Work out what a result means for your patient: probability calculator

Source

Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-Spine Rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510–2518. Journal article (DOI) · single study
Also cited: Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-Spine Rule for radiography in alert and stable trauma patients. JAMA. 2001;286(15):1841–1848. Journal article (DOI)

Website-only page, added to the library on 9 October 2026. Rule It In, Rule It Out discusses this but has no separate test card for it. Figures independently checked against the sources cited above; any note above says where only the abstract could be checked.