Abstract
OBJECTIVE: The study aimed to establish the spinal cord occupation rate of the dural sac during flexion and extension. METHODS: We measured the cross-sectional area of the dural sac and the spinal cord between C2/C3 and C7/T1 disc levels in 100 patients with cervical spondylotic myelopathy and 1211 asymptomatic subjects. RESULTS: The spinal cord occupation rate of the dural sac in the cross-sectional area was higher on extension than on flexion at the mid-lower cervical spine. CONCLUSIONS: The spinal cord occupation rate of the dural sac in the cross-sectional area was highest at the C4/C5 and C5/C6 levels on extension.