Erosion of the superior dens and smaller eroded posterior spinous processes.
Extension C1-2 distance measures: 5 to 6mm
Flexion C1-2 distance measures: 7mm
Some erosive facet change and osteopenia noted.
In flexion C2-3 4mm slip corrects in flexion, C6-7 5 to 6mm slip with correction by 4mm.