See NAEMSP National Guidelines for Spinal Immobilization
C-collar
Consult ortho or neurosurgery
External fixation via rigid cervical orthosis or halo-vest orthosis 8-14 weeks (~90% healing with immobilization alone) 
Surgical fixation, especially if there is:
Severe angulation of C2 on C3
Disruption of C2 to C3 disc space
Inability to establish or maintain alignment with external immobilization
Nonunion after use of external immobilization
External fixation via rigid cervical orthosis or halo-vest orthosis 8-14 weeks (~90% healing with immobilization alone) 
Surgical fixation, especially if there is:
Severe angulation of C2 on C3
Disruption of C2 to C3 disc space
Inability to establish or maintain alignment with external immobilization
Nonunion after use of external immobilization
Severe angulation of C2 on C3
Disruption of C2 to C3 disc space
Inability to establish or maintain alignment with external immobilization
Nonunion after use of external immobilization
Hangman's fracture
Penetrating neck trauma
Smith's fracture
Blunt neck trauma
Jefferson fracture
Vertebral and carotid artery dissection
Toddler's fracture
Strangulation