Pathological changes of cervical spinal canal in cervical spondylotic myelopathy: A retrospective study on 39 cases.

Objective: To evaluate and compare the cervical spinal canal (CSC) morphology among healthy people, cervical spondylosis myelopathy (CSM), and latent cervical spondylosis (LCS, people with cervical spine degeneration on medical imaging but without clinic symptoms).

Patients And Methods: We reviewed MRI data describing cervical spinal morphology in healthy persons, LSC patients and CSM patients. All cases underwent cervical MRI. In transverse image, anteroposterior diameter (A-P diameter), area of cervical spinal canal (CSC) and area of cervical spinal cord were measured. In sagittal image, A-P diameter was measured. Dural sac area = the area of CSC in the transverse position - the area of cervical spinal cord in transverse position.

Results: There're 8 cases in the healthy group, 18 cases in the group of LCS, and 13 cases in CSM group. Generally, the measured indicators at two ends of CSC (C2/3 and C7) are larger than those at C3-C6. A-P diameters on axial and sagittal position show a decrease trend from healthy group to LCS group and to CSM group. CSC area and dural sac area on axial position of CSM group are significantly lower than those in healthy group and LCS group. Almost all measured indicators of CSM group are significantly lower than healthy group and LCS group. Every two measured indicators in each group are significantly corelated.

Conclusions: The results suggested that CSC size of CSM was smaller than that of LCS, and A-P diameter <11 mm, CSC area <170mm and dural sac area <90 mm were more advisable to indicate cervical spinal canal stenosis in Chinese people.