Is cervical spine surgery done well from the anterior or the posterior approach? In fact, this issue is controversial in the academic spine surgery community, with scholars on both sides supporting it and having their own reasons for doing so. Since there is controversy, it also means that one cannot simply say which one is better; it should depend on the actual situation of the patient, and each has its own advantages and disadvantages. In order to figure this out, one must first understand the anatomy of the cervical spine. Briefly. The spinal cord is surrounded by a clear fluid called cerebrospinal fluid and is packed together in a sac called the dural sac, which is actually a custom-made “water sac” in which the spinal cord is suspended to protect the nerves. The dural sac containing the spinal cord travels within the spinal canal formed by the spine and is protected by the spine, which is both stable and flexible. As the old saying goes, “A fire at the gates is a disaster for the fish in the pond.” The close relationship between the spine and the spinal cord results in the spinal cord being very susceptible to abnormal changes in the spine. In front of the spinal cord are mainly the vertebrae, intervertebral discs and posterior longitudinal ligaments of the spine. In the process of spinal degeneration, vertebral bodies form bony bulges, also known as osteophytes and spurs, at the edges of the vertebral bodies; the intervertebral discs between the vertebral bodies also degenerate and age, leading to bulging and protrusion; and in some cases, the posterior longitudinal ligaments become ossified and thickened. Bone spurs, herniated discs, and hypertrophied posterior longitudinal ligaments all originate from the anterior aspect of the spinal cord and primarily cause compression of the spinal cord. In the lateral anterior part of the spinal cord, there is a hook joint formed between two adjacent cervical vertebrae, and the deformation and hyperplasia of the hook joint mainly affects the nerve roots emanating from the lateral part of the spinal cord. In the posterior part of the spinal cord, there are the vertebral plate and the ligamentum flavum of the spinal column, which become hypertrophic when degenerated and compress the posterior part of the spinal cord forward. So what is the entry point to remove the compressor that is compressing the spinal cord? The principle is simple: where there is compression, there is resistance. For anterior and lateral compressions, it is easier to remove them from the anterior approach; for posterior compressions, it is more thorough to remove them from the posterior approach. Anterior cervical spine surgery includes: anterior cervical spine decompression fusion internal fixation, anterior cervical spine subtotal resection decompression vertebral body reconstruction and fusion, or a combination of two types of surgery. In fact, the tissue compressing the spinal cord in cervical spondylosis mainly comes from the vertebral bones, degenerated discs and ossified ligaments, that is, mainly from the front of the spinal cord. So now, in cervical spine surgery, about 70-80% are done from the anterior approach of the cervical spine. There are many important structures in the front of the cervical spine, including the esophagus, trachea, cervical arteries and veins, thyroid gland, etc., so is it safe to do it from the front? The answer is: safe. From the anterior approach, you can choose to make a small transverse incision along the transverse lines of the neck, which is almost invisible after healing, and aesthetic issues are very important! After cutting through the thin muscles and fascia of the anterior cervical area, it is possible to avoid the above-mentioned important tissues and organs along a natural gap and reach the front of the cervical vertebral body, and the structure of the front of the cervical vertebrae is relatively mobile and easy to be pulled apart by the special hooks. After the cervical vertebrae are fully exposed, it is very convenient to do what kind of surgery, whether it is transcallosal decompression and fixation fusion, subtotal vertebral body excision and decompression vertebral body reconstruction and fixation fusion, or even artificial disc replacement. Therefore, nowadays, surgery for cervical spondylosis is basically done from the anterior approach. However, the anterior approach is not a panacea. If there are too many segments of cervical spine lesions, the anterior approach has limited up and down movement of the wound after all, and the length of the titanium plate of the anterior approach is also limited, then the anterior approach cannot be chosen and has to be changed to the posterior approach. There is also if the segment of the cervical spine lesion is too high, for example, above the cervical 3 vertebrae, the anterior can not be completed from the anterior approach because of the obstruction of the jaw, but needs to be changed to the posterior approach. There are also special cases, such as ossification of the posterior longitudinal ligament of the cervical spine. For one thing, the lesion is large and involves multiple segments; rather, the ossified ligament is mostly adherent to the dural sac, so the risk of the anterior approach is greater, and the posterior approach is also chosen. The posterior compression of the spinal cord is relatively much less, but there are still some, such as hypertrophy or even ossification of the ligamentum flavum and hyperplasia and hypertrophy of the vertebral plate, which can cause compression of the spinal cord from the posterior side, and to remove it completely, posterior cervical spine surgery is used. Posterior cervical spine surgery is mainly a posterior cervical spine canal enlargement, to put it bluntly, is to turn the vertebral plate and ligaments behind the spinal cord from top to bottom, from one side or both sides, to expand the space behind the spinal cord, the pressure from the rear is naturally lifted, the pressure from the front is still there, but the spinal cord can be backward to avoid it! We can’t afford to hide! Posterior cervical spine surgery was popular for a long time when the anterior cervical spine surgery technique was skilled and the anterior instrumentation was not developed. However, there are problems with posterior surgery. First, the muscles and ligaments in the posterior cervical spine were extensively damaged, making postoperative rehabilitation difficult. Because, the muscle and ligament contact with the posterior structure of the cervical spine is closely fixed firmly, the posterior muscle ligament can only play the role of fixed maintenance of the cervical spine position and pulling movement of the cervical spine, if the vertebral plate is to be revealed, sorry, it is necessary to separate the natural adequate connection between the muscle and ligament and the bone. Second, posterior surgery mostly involves fixation and fusion to multiple segments, which has a greater impact on cervical spine mobility, and patients all have a stiff neck after surgery. Third, the principle of posterior cervical spine surgery is that the spinal cord is moved backward to avoid anterior compression, but in the process of moving the spinal cord backward, the cervical 5 nerve roots are then stretched, and some patients experience symptoms of cervical 5 nerve root injury, such as shoulder pain. Therefore, nowadays, when spine surgeons are faced with cervical spondylosis, posterior surgery is only used when it has to be used. There are also some patients with compression of the spinal cord, both front and back are very severe, and then the surgeon has to choose a combined anterior and posterior surgery. Generally, the posterior approach is done in the prone position, such as a single posterior cervical canal enlargement, and then the patient is turned over in the supine position for decompression and fixation from the anterior approach. Of course, this is not a common occurrence. To sum up, the key to cervical spine surgery is the direction of compression of the spinal cord from the front or the back, which means that the condition determines the treatment.