Allen and Ferguson Classification (Subaxial Cervical Spine Injury)
Decodes an Allen and Ferguson stage of a subaxial cervical spine injury into its published definition.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Phylogeny and stage
- Distractive flexion 3: bilateral facet dislocation, 50% displacement
Result: Allen and Ferguson distractive flexion stage 3 (of 4): bilateral facet dislocation with 50% anterior displacement of the vertebral body.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Phylogeny and stage
How this is calculated
Citation
Allen BL Jr, Ferguson RL, Lehmann TR, O'Brien RP. A mechanistic classification of closed, indirect fractures and dislocations of the lower cervical spine. Spine. 1982;7(1):1-27. Stages as described in Bunzel EW, Gendelberg D. Clin Orthop Relat Res. 2024;482(7):1137-1144. Read the sources: Allen 1982 ↗, Bunzel 2024 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.