Cervical spondylosis is a degenerative disease characterized by cervical disc degeneration and secondary changes, compression or stimulation of adjacent nerves, spinal cord, blood vessels, esophagus and other tissues, resulting in corresponding symptoms and signs. With the prolongation of life expectancy and the rapid growth of the number of computer office staff, the number of patients with cervical spondylosis has also increased significantly. At the same time, due to the improvement of imaging diagnosis level, in-depth study of pathophysiological changes and pathological anatomy of cervical spondylosis, the surgical treatment of cervical spondylosis tends to be more scientific, individualized and standardized. Surgical treatment of cervical spondylosis, we should strictly grasp the surgical indications, improve the principles of surgery, and correctly handle the occurrence of postoperative complications. Chen Kai, Department of orthopedics, Fenghua people's Hospital
Since Smith Robinson and Cloward et al. Carried out anterior cervical surgery in the 1950s, the scope of surgical treatment, surgical techniques and surgical methods of cervical spondylosis have been continuously developed, and the surgical popularization rate has become increasingly widespread. But not all cervical spondylosis should be treated by surgery. Most cervical spondylosis can be cured by conservative treatment. Therefore, surgical treatment has its indications. Under the premise of mastering the indications, the operation is carried out according to the principles of decompression, stability and recovery of physiological curvature. At present, the commonly used surgical methods include anterior approach, posterior approach and combined anterior and posterior approach.
1. Surgical indications of cervical spondylosis
The patients with cervical spondylotic myelopathy and cervical spondylotic radiculopathy who failed to receive regular conservative treatment for more than 3 months, or those whose symptoms, signs and imaging findings (CT or MRI) are unified have clear indications for surgery; conservative treatment develops rapidly in 4-6 weeks, especially in patients with rapid deterioration of neurological function and bowel dysfunction, timely surgery is required.
For patients with cervical spondylosis of vertebral artery type with unstable horizontal displacement of cervical spine & Ge; 3mm or angular displacement & Ge; 11 & deg;, anterior decompression is feasible if the symptoms of vertebral artery ischemia are accompanied by vertebral basilar artery ischemia.
2. Principle of surgical treatment of cervical spondylosis
The basic principles of surgical treatment of cervical spondylosis are decompression of spinal cord and nerve tissue, recovery of cervical physiological curvature and intervertebral height, and stability of diseased segments (bone graft fusion or fixation).
2.1 decompression
The pressure factors of cervical spondylosis include soft protrusion of intervertebral disc, hypertrophic ligamentum flavum and posterior longitudinal ligament, hard hyperplastic osteophyte and ossified ligament. From the point of view of relieving the pressure of spinal cord and nerve root, direct decompression is more ideal, but indirect decompression can also be used if there is a wide range of pressure materials and can not be directly reduced. If the pressure material comes from the anterior single segment herniated disc, the anterior approach is the most direct way to reduce the pressure. However, if the posterior ligamentum flavum is compressed simultaneously from the anterior multi segmental herniated intervertebral disc, the posterior approach can be used for indirect decompression (single door or double door operation). Decompression must be thorough, completely different from extensive, at the same time to take into account the stability of the cervical spine. It is also an indirect decompression to restore the normal sequence of the cervical spine and enlarge the spinal canal volume.
2.2 bone graft fusion
Although artificial cervical disc replacement after anterior decompression has been carried out to preserve the intervertebral range of motion, the clinical observation time is short, the indications are narrow, and the long-term effect is not accurate. As the guarantee of long-term stability of the cervical spine, bone graft fusion is still the standard operation. Autogenous three sided cortical iliac bone graft is the gold standard after anterior cervical fusion. In recent years, several different types of artificial bone have been used in clinic.
2.3 fixation
In order to obtain immediate postoperative stability and facilitate early ambulation, internal fixation after decompression and bone grafting is beneficial; internal fixation also helps to maintain the physiological curvature and intervertebral height of the cervical spine and prevent complications such as collapse and fall off of the bone graft. The internal fixation of cervical spondylosis is divided into anterior fixation and posterior fixation. The anterior fixation system includes anterior plate, anterior cervical cage and artificial intervertebral disc. The anterior plate should be pre bent to adapt to the recovery of physiological curvature of the cervical spine. The screw should not penetrate the endplate or screw into the intervertebral space. Posterior internal fixation is necessary when more than three laminectomy or instability of the preserved vertebrae is performed. The posterior internal fixation system usually includes lateral mass screw system and pedicle screw system.
2.4 recovery of cervical physiological curvature and intervertebral height
The recovery of intervertebral space height and physiological curvature is the basis of maintaining normal cervical biomechanical properties. At the same time, after the recovery of intervertebral space height, the expansion of intervertebral foramen volume has obvious clinical significance for indirect decompression of nerve root; the recovery of cervical physiological curvature can restore the spinal canal volume. Indirect decompression can also be achieved. It is beneficial to the recovery of cervical vertebra physiological curvature and intervertebral height.