stability

 Articular process fracture

Natural history

Superior articular process fracture

- potentially unstable

Inferior articular process fracture

- thought to be more stable

CT scan

Definition

Bilateral Pars Fracture C2

- traumatic axis spondylolisthesis

NHx

Neurological injury uncommon

- fragments separate and decompress

Different to judicial hanging where spinal cord is severed

Xray

Issues

Wear

Stability

Normal feel of hip

Increased ROM

Wear

Large head

- increase volumetric wear

- less penetrative / linear  wear

Small head

- increased linear wear

- decreased volumetric wear

Meyers & McKeever classification

Type I:   Undisplaced avulsion fracture

Type II:  Anterior portion displaced & hinged

Type IIIA:   Displaced

Type IIIB:   Displaced & Rotated