Basilar Invagination

Definition

 - superior migration of odontoid into region of foramen magnum

 

Diagnosis

- Ranawat's < 13 mm (pedicle of C2 to line of axis)

- McGregor's > 4.5 (hard palate to base occiput)

- McCrae's - dens above line of foramen magnum

 

Congenital / SAD MAN BOOK

 

SED

Achondroplasia

Downs

 

Morquio

Atlas Hypoplasia

NF   

 

Bifid posterior arch atlas

Occipitocervical synostosis

OI

Klippel Feil syndrome  

     

Acquired

 

JRA

Rickets

RA