Abstract
One-stage surgery, transoral anterior decompression and posterior fixation, were performed in 14 cases of irreducible atlantoaxial dislocation (AAD) with anterior cord compression. There were 4 males and 10 females with average age being 52 years and 6 months, and with 3 year follow-ups. Dynamic X-ray and tomography, magnetic resonance imaging and computed tomography were essential in diagnosis of irreducibility and anterior cord compression in AAD which were important conditions for selecting one-stage surgery. As to the positioning of patients in the operating room, supine-prone position was used in 7 and lateral rotatory position in 7. The operative method of posterior fusion has greatly changed over the years and various instruments have recently been used. Transarticular screw fixation in addition to midline bony fusion can be applied to cases with severe degree of AAD or marked instability, however, precise preoperative evaluation for high riding transverse foramen and intraoperative navigation system are recommended in order to avoid serious injury to the vertebral artery. Surgical results were satisfactory in 86% but the surgical timing was important since the results of cases with severe myelopathy was not always favorable. In conclusion, one-stage surgery is a very useful and effective method in cases with irreducible AAD and solid posterior fixation can be obtained by well-planned instrumentation.
