Treatment of traumatic atlanto-occipital dislocation in chronic phase.

We report the case of 27-year-old woman who presented with mild neurological deficits with significant anterior dislocation of the atlanto-occipital junction in a chronic phase after initial conservative treatment in another hospital. The importance of early diagnosis and treatment for atlanto-occipital dislocation is emphasized. The dislocation could not be reduced sufficiently either by halo ring cervical traction or surgical procedure 5 months after the accident. Therefore, transoral odontoidectomy for decompression of the medulla, together with the posterior occipitocervical fusion with a titanium loop brace was performed. The patient's symptoms disappeared completely within a few months after the operation. Magnetic resonance imaging findings suggesting soft tissue damage is the key to an early diagnosis and subsequent stabilization of traumatic atlanto-occipital dislocation in the early phase. Transoral decompressive odontoidectomy combined with posterior fusion may be considered for the treatment of irreducible atlanto-occipital dislocation in a chronic phase.