Revision surgery of irreducible atlantoaxial dislocation: a retrospective study of 16 cases.

There is lack data concerning anterior cervical spine revision surgeries; even more data are missing concerning posterior cervical revision surgeries, to determine the feasibility, safety, and clinical efficacy of revision surgery for irreducible atlantoaxial dislocation (RS-IAAD). Patients with IAAD-FS underwent one-stage transoral release and posterior reduction. Their medical history was documented in detail. The JOA score system was used to evaluate each patient's neurological status pre and postoperatively, and serial MRI and radiographs were used to determine the status of the reduction and the autografts. 16 patients (average age, 36 years old) underwent successful surgery. There was no intraoperative or postoperative neurological deficit except in two cases that suffered transient neurological deficit that alleviated after conservative treatment. Solid bony union was seen at the end of 3 months after surgery in all patients. The mean follow-up period was 28.8 months (range 18-66 months). No pseudarthrosis was noted. Anterior transoral release and posterior instrumented fusion remain significant surgeries with the potential for serious complications, but in the current series there were no major complications.