This study evaluated the relationship beween spinal canal anteroposterior diameter, canal-body ratio and height. Subjects consisted of 50 patients with cervical spondvlotic myelopathy, and a control group of 50 healthy male volunteers. The anteroposterior dimensions of the vertebral bodies and spinal canal were assessed on lateral roentgenograms, using a target distance of 150cm. The width of the canal was measured between the midpoint of the posterior cortex of the vertebral body to the closest point on the spinolaminar line. The width of the vetebral body was measured at its center.
Results revealed that the spinal canal anteroposterior diameter was narrower in the cervical spondylotic myelopathy group compared to the control group. In contrast there was no significant difference between the 2 groups in regard to vertebral body anteroposterior diameter. A correlation between anteroposterior dimensions of the vertebral bodies and spinal canal height was recognized in the control group. However, no correlation between canal-body ratio with body height was seen in either group. A significant difference in canal-body ratio was seen between the control group and cervicl spondylotic myelopathy group (p<0.01).
We consider that the canal-body ratio is an effective determination method for cervical canal stenosis.
