OrthoNet

Spine - Cervical Spine Anatomy

Atlas - 3 ossification centers (body, two lateral masses)

Axis - 5 ossification centers plus terminal ossicle; the dens is made of two which are fused at birth, so in reality it appears as if it only has 4 centers - dens, body, two lateral masses. The neurocentral synchondrosis that separates the dens from the body and lateral masses usually fuses at age 3, but may not fuse until age 7 and can be confused with an odontoid fracture.

Anterior ADI - usually 3-5 mm in a child less than 8 yrs old. After 8, should be no more than 3
- ADI of 5-10: implies transverse ligament rupture
- ADI of > 10: implies alar ligament rupture too.

The facets are more horizontal, and the ligaments are more lax than adults - makes the pediatric c-spine much more susceptible to injury.