Spondyloepiphyseal dysplasia congenita (SED) is a rare form of skeletal systemic 
disease, characterized by congenital dwarfism with a short trunk and epiphysial 
dysplasia in the long bones and vertebral bodies. Patients also frequently 
suffer from atlanto-axial instability due to os odontoideum. Compression of the 
spinal cord caused by atlanto-axial instability is a common, serious 
complication in SED patients, and causes severe spinal cord symptoms or 
occasionally sudden death. We present an SED patient who underwent a posterior 
fusion of the occiput to the cervical spine for severe spinal cord symptoms due 
to atlanto-axial instability.