Cervical dural sac compression does not mean that the spinal cord is compressed. The spinal cord is composed of the parenchymal nerve cells of the spinal cord and the dural sac, respectively, with cushioning in between, such as cerebrospinal fluid and fatty tissue. Therefore, if the degree of cervical dural sac compression is not severe, it is possible that the spinal cord is not being compressed. If the compression of the dural sac is more severe, the compression of the soft tissues between the dural sac and the spinal cord will inevitably lead to compression of the spinal cord and therefore to clinical symptoms of spinal cord injury. If the compression is very mild, only the dural sac is compressed and there may be no spinal cord compression.