This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
Why a decision rule for neck injuries?
Millions of people visit emergency departments each year after car crashes and falls with neck pain, yet only about 1 to 2% have a fracture or ligament injury of the cervical spine. Imaging everyone exposes patients to radiation and long waits; missing an injury can lead to paralysis. Ian Stiell and colleagues in Canada derived the Canadian C-spine rule in 2001 from nearly 9,000 patients to pick out those who truly need imaging.
Who it applies to
Alert (Glasgow Coma Scale 15) and stable adults aged 16 or older after blunt trauma to the head or neck. It does not apply to children, penetrating injuries, acute paralysis, known spinal disease such as ankylosing spondylitis, previous neck surgery, pregnancy, or patients returning for the same injury.
Step 1: any high-risk factor means imaging
- Age 65 or older
- Dangerous mechanism: a fall from 3 feet or 5 stairs, an axial load on the head such as diving, a high-speed crash (over 60 mph or 100 km/h), a rollover or ejection, a crash in a motorized recreational vehicle, or a bicycle collision
- Numbness or tingling in the arms or legs
Step 2: is there a low-risk factor that allows a safe exam?
- A simple rear-end car collision
- Sitting up in the emergency department
- Walking at any time since the injury
- Delayed onset of neck pain
- No tenderness over the midline of the back of the neck
If none is present, the neck cannot be safely tested and imaging is indicated.
Step 3: can the patient turn the head?
If at least one low-risk factor is present, the patient is asked to actively turn the head 45° to the left and to the right. If they can, no imaging is needed. If they cannot, imaging is indicated.
Example
A 40-year-old who walked after a low-speed crash, has no midline tenderness and turns the head freely has no high-risk factor, two low-risk factors and a normal rotation: the rule is negative.
How well it works
In the original validation the rule detected nearly all clinically important injuries. In a 2003 comparison it was more sensitive than the NEXUS criteria (99.4% versus 90.7%). Imaging today is usually a CT scan. The rule supports, and does not replace, the judgment of the treating clinician.