Traumatic atlanto-occipital dislocation with atlantoaxial subluxation.

Study Design: This is a case report of a patient who survived traumatic atlanto-occipital dislocation with atlantoaxial subluxation.
Objective: To describe the useful points of 3-dimensional computerized tomography (CT) and magnetic resonance imaging (MRI) for an evaluation of atlanto-occipital dislocation.
Summary of Background Data: Atlanto-occipital dislocation is a severe ligamentous injury that usually results in either a fatal outcome or severe neurologic deficit. To our knowledge, no patient who has survived atlanto-occipital dislocation with atlantoaxial subluxation has yet been reported.
Methods: Three-dimensional CT was performed to confirm the diagnosis of atlanto-occipital dislocation and precisely evaluate the magnitude of displacement. MRI clearly showed a disruption of the ligamentous structures, which play a role as the primary stabilizers of the cranium on the cervical spine.
Results: As soon as the patient's general condition improved, the posterior spinal fusion with internal fixation was performed to maintain the stability of cervical spine. A significant degree of motor function was regained within 2 years after injury.
Conclusions: In this case, the diagnosis was accurately confirmed, and the cervical spine was evaluated in detail using both 3-dimensional CT and MRI as a reliable examination for atlanto-occipital dislocation.