Traumatic C1–2 posterolateral dislocation with dens fracture, injury of the transverse atlantal ligament, and unilateral facet fracture with subluxation of C6–7

Rationale: Traumatic C1–2 dislocation associated with contiguous or noncontiguous cervical spine injury is rare. Moreover, there have been no reports describing traumatic C1–2 dislocation associated with multiple contiguous and noncontiguous cervical injuries. Patient concerns: The authors present a case of a 20-year-old male with painful limitation of motion of the neck. This complex cervical injury occurred due to hyperextension of the head in a rotated position. The patient complained of neck pain that radiated to the left shoulder and arm, but he did not exhibit any neurological abnormalities. Diagnoses: The diagnosis of the patients was traumatic C1-2 posterolateral dislocation associated with type II dens fracture (Anderson and D’Alonzo classification), type II injury of the transverse atlantal ligament (Dickman classification), and unilateral facet fracture with subluxation of C6–7. Interventions: The C1–2 posterolateral dislocation with type II dens fracture was successfully reduced by skull traction. The patient underwent anterior discectomy, open reduction, and fusion with plate fixation of C6–7 followed by posterior segmental fixation and fusion of C1–2. Outcomes: At his postoperative 1-year follow-up, solid fusion was noted with improvement of clinical symptoms. This is the first report of traumatic C1–2 posterolateral dislocation associated with multiple C2 injuries and noncontiguous subaxial cervical injury. Lessons: A high index of suspicion and careful evaluation of entire cervical spine should be considered as the key to the proper diagnosis and treatment of traumatic C1–2 dislocation associated with contiguous and noncontiguous cervical injuries.