Degenerative changes of the cervical disc and its secondary lesions are the fundamental lesions of cervical spondylosis, so the pathology is described in two parts: 1. Primary lesions; i.e., disc degeneration, herniation, prolapse, etc. (1) Loss of water in the nucleus pulposus and annulus fibrosus; with age, aging of the cervical disc begins with loss of water in the nucleus pulposus and annulus fibrosus. The mucus matrix and fibrous tissue network of the nucleus pulposus are gradually replaced by fibrous tissue and chondrocytes, becoming fibrocartilage, losing its bearing and hydraulic role, and aggravating the burden of the fibrous ring. After the loss of water in the fibrous ring, the elastic fibers become thicker, undergo hyaline degeneration, lose elasticity, and lose the function of maintaining the nucleus pulposus in the central part of the intervertebral disc. (2) Rolling injury of the annulus fibrosus buckles the bulging, protrusion and prolapse of the intervertebral disc: because the water content of the nucleus pulposus is more than that of the annulus fibrosus. The water loss of the nucleus pulposus is also more, so the weight and activities of the head and neck are gradually borne by the annulus fibrosus, due to the activities of the neck, the annulus fibrosus is ruptured by tumbling injury, from small fissures to large fissures, and the intervertebral disc then bulges, protrudes or prolapses. Since there is a tough posterior longitudinal ligament in the posterior part of the vertebral body and a ~ crack in the middle, the disc generally protrudes at the lateral part of the weaker posterior longitudinal ligament, and a few protrude in the middle of the posterior side. These two protrusions are the most notable. Because there are symptoms of nerve root and spinal cord compression, while other herniations such as anterior, lateral, and superior and inferior herniations do not have important structures being compressed, their symptoms are not as severe as those of posterior lateral and posterior median herniations. Three types of inflammation occur locally in herniated discs. (1) traumatic inflammation; (2) chemical inflammation caused by histamine released from the ruptured tissue; and (3) autoimmune reaction caused by the herniated nucleus pulposus tissue. As a result, severe edema can occur at the rupture and expel the herniated material, but when the edema subsides, the herniated material can sometimes be incorporated back into the disc. (3) Total disc degeneration: The disc herniation initially herniates in one direction, but promotes more severe degeneration of the disc, which eventually becomes total disc degeneration, bulging and protruding in all directions. The degenerated disc will lose more elasticity and stability, and even the upper and lower cartilage plates can rub directly against each other and more damage will occur. The narrowing of the intervertebral space and some secondary lesions can be seen on the X-ray. 2, secondary lesions: (1) bone superfluous formation: this is the most common X-ray signs, occurring in the upper and lower edges of the vertebral body and the edge of the joint, like the lips of children gambling, so also known as lip-like changes, osteophytes, bone spurs, bone superfluous, etc., is a special manifestation of osteoarthritis. Take the vertebral body and intervertebral disc as an example, they are indirectly connected joints. In the vertebral body, there is an outer periosteum immediately attached to the surface of the vertebral body regardless of the front and back, ending at the upper and lower edges of the vertebral body, and its outer layer is connected to the anterior, posterior, and collateral longitudinal ligaments, but there is no outer periosteum on the surface of the intervertebral disc, which resembles the joint capsule of the indirect connection type. After the disc degeneration, the disc loses its height, the intervertebral space becomes narrower, and it loses the role of stabilizing the diseased segment, making it difficult to control the paradoxical activities of the diseased segment. As a result, the degenerated disc extrudes in all directions under pressure, lifting the outer periosteum attached to the edge of the vertebral body and forming lip-like osteophytes under the periosteum. Paradoxical movement of the spinal segment exacerbates the periosteal lifting and creates more severe osteophytes. In indirectly connected joints, i.e., synovial and hooked joints, the synovial joint can be misaligned up and down due to loss of intervertebral disc height, which distorts the joint capsule and causes osteoarthritis. The hook vertebral joint is also damaged by compression. These two joints are also affected by osteoarthritis. The pain and other symptoms are caused by: (1) compression of nearby nerves and blood vessels; (2) destruction and distortion of intervertebral discs and ligaments; and (3) reflex muscle spasm. The direction of cervical disc herniation is most common in the posterior lateral side, and this direction is the narrowest part of the vertebral canal on one side of the crypt to the intervertebral foramen, with the hook vertebral joint, intervertebral disc and vertebral body edge in the front, and the joint synovial joint in the back, if there is disc herniation and bone superfluity, the nerve root will be compressed in this bone channel, and cause symptoms. Another example is the posterior side of the vertebral space, which can form a transverse hard plug and compress the spinal cord causing spinal cord symptoms. Another example is that the anterior cervical vertebrae can compress the esophagus, and both sides can compress the vertebral artery. (2) Joint misalignment and ligament relaxation and distortion: each cervical vertebral segment becomes a 5-point closed system, so the narrowing of the intervertebral space caused by disc degeneration will cause pathological changes such as overlapping misalignment, joint capsule distortion and bone redundancy in the other 4 points (both sides of the hook vertebra and articular eminence joint). The intervertebral disc’s fibrous ring, posterior longitudinal ligament and joint capsule are supplied by the sinus vertebral nerve, so these lesions do not directly cause pain, but distant induction pain can occur. (3) Ligamentous laxity, hypertrophy, calcification and ossification: narrowing of the intervertebral space causes laxity of the anterior and posterior longitudinal ligaments, the ligamentum flavum and the interspinous and supraspinous ligaments that maintain the stability of the segment. The loss of stability of the spine in this segment stimulates these ligaments by paradoxical activity. To compensate, they hypertrophy, calcify and ossify. In the space-limited spinal canal, laxity of the ligamentum flavum, in cervical hyperextension, can crease and compress the cervical medulla; hypertrophy of the ligamentum flavum and ossification of the posterior longitudinal ligament will also compress the cervical medulla. (4) Adhesions; posterior median protrusion of the intervertebral disc may adhere to the dura mater of the cervical medulla; posterior lateral protrusion of the cervical disc may adhere to the nerve root or root cuff, causing fibrosis of the spinal cord and nerve root, perpetuating the symptoms and making them difficult to cure. (5) Myospasm; stimulation of nerves and nerve roots can cause reflex myospasm. Some cases of frozen shoulder are not caused by rotator cuff or shoulder joint disorders, but by the reflex muscle spasm of the lower cervical cervical spondylosis. Some cases of “pillow drop” are often caused by reflex spasm of the upper cervical cervical spine. Reflex muscle spasm is a self-defense reaction of the body. (6) Induction pain: It is the pain felt in the area innervated by other branches of the same nerve after a branch of the spinal nerve is stimulated, but the area is vague, without pressure pain and nerve signs, but there may be muscle spasm. Various different types of cervical spondylosis: mostly caused by secondary lesions of the cervical spine. Radicular cervical spondylosis is caused by the posterior lateral herniation of the intervertebral discs together with bony redundancy of the hook and synovial joints; secondary pathological fractures such as ossification of the posterior longitudinal ligament, which narrow the spinal canal and compress the cervical medulla (spinal cervical spondylosis); instability of the cervical spine and bony redundancy of the posterior lateral edge of the vertebral body, which can irritate or compress the vertebral artery (vertebral artery cervical spondylosis) or stimulate the cervical sympathetic chain; bony redundancy of the anterior vertebral body can irritate or compress the esophagus, etc. The bony bulge in the anterior part of the vertebral body can irritate or compress the esophagus, etc. .