Large vertebral body, in addition to narrow spinal canal, are risk factors for cervical myelopathy

It is well known that a narrow spinal canal is frequently associated with cervical spondylotic myelopathy. However, few investigators have studied the relationship between the size of the cervical spinal canal and that of the cervical spinal cord. Moreover, no studies mention the correlation between the size of the vertebral body and that of the spinal canal in the pathogenesis of cervical myelopathy. In the present study, we used computed tomographic myelography to measure the size of the vertebral body, spinal canal, and spinal cord in patients who had classic cervical myelopathy and in control subjects. We found that patients with cervical spondylotic had a narrow spinal canal as well as a slender spinal cord in the cervical region. Moreover, the vertebral body is significantly larger in the myelopathy group than in controls. A large vertebral body is thought to be associated with a large osteophyte and large disc protrusion. We conclude that a large vertebral body is another risk factor for cervical myelopathy, along with a narrow spinal canal.