[Atlanto-axial instability presenting a rare complication in fibrous dysplasia - a case report].

Fibrous dysplasia, in either monostotic or poliostotic form rarely involves the cervical spine. Most of these lesions remain asymptomatic and are incidental radiographic findings. A symptomatic case of polyostotic fibrous dysplasia involving the first, second and third cervical vertebra with potentially serious consequences is presented. A 53-year old woman who had shown cervical myelopathy for about 3 month was diagnosed as having cervical dysplasia on the basis of plain x-ray and CT scanning. In addition, atlanto-axial instability causing clinical symptoms was detected. A dorsal stabilisation was performed using the DCS System.