Science today isn't the same as the science 2000 years ago was but some principles remain the same. The human knowledge constantly grows but with more knowledge there comes even more mysteries and unsolved questions, so science is always going forward.
Causes. The most common cause of a cervical herniated nucleus pulposus is gradual degeneration of the disc, attenuation (weakening) of the posterior annulus fibrosis, and subsequent protrusion of the nucleus pulposus into the spinal canal causing compression of the nerve root.
The ligament and posterior capsule of the disk are usually torn, allowing the nucleus pulposus to extrude, compressing the nerve root. Occasionally, the injury tears the entire disk loose, causing protrusion onto the nerve root or compression of the spinal cord. Large amounts of extruded nucleus pulposus or complete disk herniation of the capsule and nucleus pulposus may compress the spinal cord.