Type A: Isolated bony injury (condyle)
Type A injuries are any type of occipitocondyle fracture (simple or multifragmentary) without significant...
Occipitocervical trauma
Region I: Occipital condyle and craniocervical junction
Type B: Nondisplaced ligamentous injury (craniocervical)
Type B injuries are nondisplaced ligamentous injuries with or without associated fractures of the occipital...
Type C: Any injury with displacement
Type C injuries are any injury with significant translation between the occiput and the cervical spine in any plane.
Region II: C1 ring and C1–C2 joint
Type A: Isolated bony injury
Type A injuries are any C1 fracture (simple or multifragmentary) without significant ligamentous...
Type B: Nondisplaced ligamentous injury
Type B injuries are transverse atlantal ligament insufficiencies, which may or may not be associated...
Type C: Translation injury of the C1–C2 joint
Type C injuries are all injuries with atlantoaxial instability or displacement in any plane.
Region III: C2 and C2–C3 joint
Type A: Isolated bony injury of C2
Type A injuries are any C2 fractures (simple or multifragmentary) without significant ligamentous or...
Type B: Nondisplaced ligamentous injury
Type B injuries are tension band/ligamentous injuries, with or without bony injury.
Type C: Translation injury
Type C injuries are any injuries that lead to a displacement between C2 and C3.
