Patient: upper limb numbness, lower limb walking weakness, stepping on cotton-like, unstable high and low for 4 months. Traction in several hospitals above the mainland level, ineffective and aggravated by medication. How should I treat it? MRI shows C3-6 spinal stenosis and calcification of ligaments. A: Hello, patient! Your case may be ossification of the posterior longitudinal ligament of the cervical spine (OPLL), a disease that causes chronic compression of the spinal cord and nerve roots, the result of the interaction of multiple factors such as genes and the environment, the pathogenesis of which is currently unknown, the pathology is the occurrence of ectopic bone formation within the posterior longitudinal ligament. Factors associated with the disease include cervical posterior longitudinal ligament hypertrophy, cervical disc herniation, genetic abnormalities of D. collagen and abnormal glucose metabolism. The radiographic features of the disease are abnormally elevated striations at the posterior edge of the vertebral body. There are usually four types: continuous, segmental, mixed and nodal. To accurately determine the degree of cervical spinal stenosis, plain radiographs or tomographs can be used to measure the stenosis rate of the cervical spinal canal, combined with MRI to determine the degree of compression of the cervical spinal cord by the ossified mass. It appears as a thin non-calcified layer on lateral radiographs or CT films and histologically consists of dense fibrous tissue at the posterior aspect of the vertebral body and fibrocartilage cells and stroma at the base of the exophytic bone mass. Cervical disc herniation is closely associated with the development of ossification of the posterior longitudinal ligament of the cervical spine Cervical disc herniation is often associated with cervical OPLL. The mechanism by which cervical disc herniation promotes the occurrence of OPLL may be twofold: first, mechanical factors, i.e., the intervertebral space of the herniated disc repeatedly stimulates the posterior longitudinal ligament due to intervertebral joint instability during cervical spine motion, causing hyperplastic ossification; second, the herniated disc secretes humoral growth factors, promoting hyperplastic hypertrophy and ossification of the posterior longitudinal ligament. Treatment: According to the condition, both non-surgical and surgical methods are chosen: the common surgical methods for OPLL treatment are: anterior decompression implant internal fixation; posterior decompression implant internal fixation; combined anterior and posterior access decompression surgery. The anterior approach allows for the direct removal of the anterior compression ossification foci from the spinal cord, providing complete decompression of the spinal cord while maintaining the structural integrity of the spine with anterior internal fixation to avoid the motor imbalance caused by the destruction of the anterior spinal column. However, because the ossified posterior longitudinal ligament often involves multiple segments, anterior surgical decompression is more extensive and disruptive to the integrity of the cervical spine, and postoperative complications are more frequent. Indications for anterior decompression fusion: segmental type (less than 2 vertebrae); limited type; combined disc herniation. Indications for posterior decompression: extensive OPLL of greater than 3 vertebral bodies; continuous and mixed; combined developmental spinal stenosis. Direct decompression can be achieved through laminar decompression or laminoplasty, and with the help of the physiological anterior convexity of the cervical spine, the cervical medulla appears to be displaced posteriorly. Posterior surgery is particularly suitable for patients with severe cervical spinal cord injury and severe spinal stenosis because of its simplicity and less damage to the anteriorly compressed spinal cord over time, and the scope of decompression is not affected. We use posterior decompression lateral block screw fixation, direct posterior decompression of the vertebral plate opening, which not only relieves the compression of the spinal cord by the yellow ligament fold and hypertrophy, but also indirectly relieves the compression from the front of the spinal cord through the posterior displacement of the spinal cord, and the nail rod system of the internal fixation system can restore the physiological anterior convexity of the cervical spine as much as possible through the pre-bending rod, rotating rod and other techniques, using the bowstring principle, so that the compression from the front of the cervical cord can be further relieved indirectly. Indirectly, the pressure from the front of the cervical medulla is further relieved, and the stability of the cervical spine is rebuilt, thus reducing the possibility of re-injury to the cervical medulla. Satisfactory treatment results can be obtained.