Fibrous Dysplasia of the Cervical Spine with Atlanto-axial Dislocation

We report on a case of fibrous dysplasia of the cervical spine accompanied by atlanto-axial dislocation, a rare condition first reported by Stirrat. A 37-year-old man who had shown cervical myelopathy for about 6 months was diagnosed as having cervical fibrous dysplasia on the basis of plain x-ray and CT film findings. In addition, atlanto-axial dislocation, which was the apparent main cause of his symptoms, was also detected. We performed a successful two-stage operation from first the posterior and then the anterior approach. The possibility that grafted cancellous bone for anterior fusion may be replaced by dysraphic tissue in the presence of fibrous dysplasia was a complicating factor in this case.