Multilevel cervical disconnection syndrome: initial description, embryogenesis, and management. Report of two cases.

Two cases of a previously undescribed cervical spinal anomaly distinct from cervical spondylolysis are presented. The authors report the first detailed description of a congenital vertebral anomaly characterized by multilevel cervical spondylolysis, sagittal deformity, and spinal cord compression. The sine qua non of the condition is a lack of communication between the anterior and posterior columns of the cervical spinal canal, which may occur over several vertebral levels. A kyphotic deformity of the anterior column occurs, whereas the posterior column may have relatively normal alignment. The underlying biomechanical stresses caused by the anterior-posterior column disconnection result in spinal instability and progressive kyphotic deformity, often to a profound degree. Two children, 2 and 3 years of age, presented with congenital multilevel disconnection and myelopathy. In the first stage of treatment, each underwent an anterior decompression, reduction, and reconstruction of the involved segments. This was followed by posterior stabilization and fusion as a separate procedure. In both patients, the myelopathy improved and a solid, circumferential fusion was achieved. The authors' success in treating these patients indicates that management of these conditions can be based on the principles of deformity correction, spinal cord decompression, and combined anterior-posterior arthrodesis.