Anterior surgery in four consecutive technical phases for cervical spondylotic myelopathy.

Between 1960 and 1990, 175 patients having anterior operations for cervical spondylotic myelopathy were evaluated during the course of four operative phases. Specific attention was paid to spine and spinal cord morphologic changes occurring in 52 patients, who were followed up for more than 12 years. Although overall outcomes were satisfactory, a disturbing incidence of neurologic deterioration caused by spondylolisthesis at levels adjacent to fused segments, kyphosis, and altered cord morphology was noted 10 years after surgery. These changes, observed in patients with multilevel pathology and a narrowed spinal canal, promoted the adoption of more stringent operative criteria, including ultrasonically confirmed 16-mm or greater anterior trough decompressions and the performance of long fusions with vascularized fibular struts.