Cervical myelopathy in the Japanese.

Surgeries (1155 cases) for cervical myelopathy in a northeastern prefecture (population, 2.26 million) and surrounding areas were reviewed. The annual operation rate per 100,000 residents in the prefecture was 5.7. Most of the patients were in their sixth or seventh decade of life (27% each), but the annual operation rate per 100,000 people of each decade of age was the highest in the eighth decade (16.5 per 100,000 people). At the largest spine center, 41% of 306 patients had a preoperative disease period of more than 1 year, and 65% had severe disabilities. Anterior and posterior compression were about equally chosen. The former, mainly indicated for younger adults and single- or 2-level spinal cord compression, led to better functional improvement. Laminoplasty (93%) was predominant over laminectomy. Forty percent of the patients had developmental stenosis; 48%, dynamic stenosis; 27%, disc herniation; 11%, segmental ossification of the posterior longitudinal ligament; 9%, continuous ossification of the posterior longitudinal ligament; 8%, posterior spur; and 4%, calcification of the ligamentum flavum. Fifty-two percent had more than 1 of these spinal diseases.