Stage Description of injury 1 Magnetic resonance imaging (MRI) evidence of injury to craniocervical osseoligamentous stabilizers; craniocervical alignment within 2 mm of normal; distraction of [less ahtn than or equal to] 2 mm on provocative
traction radiography 2 MRI evidence of injury to craniocervical osseoligamentous stabilizers; craniocervical alignment within 2 mm of normal; distraction of >2 mm on provocative
traction radiography 3 Craniocervical malalignment of >2 mm on static radiography