Evaluate with the Powers ratio
Ratio of BC:OA > 1 suggests anterior subluxation
BC = distance between basion and midpoint of C2 post laminar line
OA = Distance between opisthion and ant arch of C2
Basion to dens interval of > 10mm 
Ratio of BC:OA > 1 suggests anterior subluxation
BC = distance between basion and midpoint of C2 post laminar line
OA = Distance between opisthion and ant arch of C2
Atlanto-occipital dissociation
Penetrating neck trauma
Scapulothoracic dissociation
Blunt neck trauma
Epidural hemorrhage
Vertebral and carotid artery dissection
Lisfranc injury
Strangulation