Acute traumatic lateral atlantoaxial dislocation associated with locked atlas lateral mass and odontoid process fracture: A clinical case study and literature review.

Background: Traumatic atlantoaxial dislocation combined with locked atlas lateral mass and odontoid process fracture is a complex injury and is extremely rare. We describe the surgical technique by presenting a clinical case study in managing a traumatic lateral atlantoaxial dislocation combined with a locked atlas lateral mass and a type II odontoid fracture (Grauer type IIB). Case description: This is a clinical case study of a 38-year-old female patient who presented with severe neck pain without neurological deficit following a traffic accident. Computed tomography showed a type IIB odontoid fracture and a lateral C1-C2 dislocation with a laterally locked left lateral mass at the C1-C2 level. Emergency management included protecting the cervical spine and applying gradually increasing skull traction. The locked lateral mass and laterally-dislocated C1-C2 facet joints were partially reduced. An intraoperative joint reduction operation with leverage technique was then performed. Posterior C1-C2 fixation (a modified Harms-Goel technique) and fusion with iliac bone graft were then executed. Outcome: Postoperatively, neck pain improved significantly. The atlantoaxial joint was successfully reduced and stabilized. Solid bony fusion was confirmed by a radiographic study at the 1-year follow-up. Conclusions: Based on a review of current literature, traumatic lateral atlantoaxial dislocation combined with a locked atlas lateral mass and type IIB odontoid fracture is rarely seen. It is an extremely unstable injury. Our proposed leverage technique used in conjunction with a modified Harms-Goel technique is an effective alternative treatment. This approach can assist surgeons in the management of these difficult cases.