====== Anterior Atlanto-axial subluxation ======

===== General information =====

One-third of patients with anterior [[Atlanto-axial subluxation]] have a neurologic deficit or die. 

[[Subluxation]] may be due to:

1. disruption (rupture) of the [[transverse atlantal ligament]] (TAL): the [[atlantodental interval]] (ADI)
will be increased

a) attachment points of the TAL may be weakened in [[rheumatoid arthritis]]

b) trauma: may cause anatomic or functional ligament disruption

2. incompetence of the [[odontoid process]]: ADI will be normal 

a) [[odontoid fracture]]

b) congenital hypoplasia,e.g.[[Morquio syndrome]]