Retrospective analysis of 131 axis ring fractures from Canada and Australia, proposing the first systematic three-type classification. Types are defined by C2 body displacement, C2-3 disc space integrity, and C2-3 facet joint status. Each type carries distinct stability, neurological risk, and treatment implications.
Before Effendi, all bilateral C2 pedicle/pars fractures were lumped together as "hangman's fractures" with no systematic framework to guide treatment. The eponym obscured critical differences in stability and risk.
When you see a C2 ring fracture on CT, apply the Effendi classification immediately: no C2 body displacement with a normal C2-3 disc space is a stable Type I — manage in a hard collar or brace for 6 weeks and do not attribute any persistent neurological deficit to it.
Any obvious C2 body displacement makes it a Type II: get dynamic flexion-extension films under supervised mild traction, start halo immobilization, and cap skull traction at 4 kg. If instability persists at 12 weeks, anterior C2-3 fusion is justified. But not before.
If the C2-3 facets are locked in flexion, you have a Type III: plan for open reduction because traction will not work, use interspinous wiring, then manage as a Type II. The 33% mortality in Type III reflects the severity of associated injuries, particularly cord injury and head trauma, not just the fracture pattern itself.
Retrospective analysis of 131 axis ring fractures from Canada and Australia, proposing the first systematic three-type classification. Types are defined by C2 body displacement, C2-3 disc space integrity, and C2-3 facet joint status. Each type carries distinct stability, neurological risk, and treatment implications.
Before Effendi, all bilateral C2 pedicle/pars fractures were lumped together as "hangman's fractures" with no systematic framework to guide treatment. The eponym obscured critical differences in stability and risk.
When you see a C2 ring fracture on CT, apply the Effendi classification immediately: no C2 body displacement with a normal C2-3 disc space is a stable Type I — manage in a hard collar or brace for 6 weeks and do not attribute any persistent neurological deficit to it.
Any obvious C2 body displacement makes it a Type II: get dynamic flexion-extension films under supervised mild traction, start halo immobilization, and cap skull traction at 4 kg. If instability persists at 12 weeks, anterior C2-3 fusion is justified. But not before.
If the C2-3 facets are locked in flexion, you have a Type III: plan for open reduction because traction will not work, use interspinous wiring, then manage as a Type II. The 33% mortality in Type III reflects the severity of associated injuries, particularly cord injury and head trauma, not just the fracture pattern itself.