The ABCs of the cervical spine provide a helpful mnemonic to guide the systematic assessment of these x-rays. Remember, you need all three views (lateral, AP and odontoid/open mouth view) for an adequate study.
A: Adequacy
The C7/T1 junction must be visible
A: Alignment
Ensure all four lines are contiguous/uninterrupted
1. Anterior longitudinal line
2. Posterior longitudinal line
3. Spinolaminal line
4. Spinous process line
B: Bones
Each vertebra must be examined for fracture/collapse/avulsion.
Parallel facet joints.
C: Cartilage (aka disc spaces)
Examine for symmetry/normality of the intervertebral discs between each vertebrae
S: Soft tissue
Prevertebral swelling of <2/3 of adjacent vertebral width
<7 mm anterior to C2
<2 cm anterior to C7
S: Spaces and lines
Pre-dental space
Normal <3 mm
>3 mm (XR) or 2 mm (CT) ?damage to transverse ligament
>5 mm implies rupture of transverse ligament
Basion-dental interval
A marker of occipito-atlantial dissociation
<12 mm on x-ray or
≤8.5 mm on CT
Line of Swischuk
Helps differentiate pathological anterior displacement of the cervical spine (typically C2/3) from physiological displacement, termed pseudosubluxation.
A line is drawn between the anterior aspect of C1 and C3 spinous processes.
The anterior aspect of C2 spinous process should be within 2 mm of this line.
Deviation >2 mm: indicative of true subluxation.
Deviated <2 mm: consistent with pseudosubluxation
A: No subluxation. Therefore, posterior cervical line (PCL) cannot be applied. Anterior aspect of spinous process of C2 commonly misses PCL by 2 mm.
B: Subluxation is present. The anterior aspect of spinous process of C2 misses the PCL >2 mm. Finding is suggestive of a hangman’s fracture of the neural arches of C2.
C: Pseudosubluxation is present. The anterior aspect of spinous process of C2 touches or lies within 2 mm of PCL.
Emergency medicine Arabic board
Nice… 5 stars
Is this site still up & running? I noticed everything is from 2yrs ago?! :/
We’ve been going since 2013 and are still posting 3 times a week, Mindy.
Take a look at the home page.
hi great presentation Chris, But I was wondering what you referred to as a “one of the rare ED docs with an Australian accent!” about your self?
Very informative and easy to understand.
This is great, particularly like the way pseudosubluxation is explained.
Thanks!! Very concise!!
very nice and very well received . thanks
Very very well explained
excellent stuff
Excellent! Very clear and concise. Really enjoyed it!
A very helpful webpage Dr Chris. I hope I never find or miss any of these nasty presentations in practice.
Nice images! However a further magnifying option would be useful for some of the images even when they are at full size..