Many people are very worried and even fearful when they see their lumbar or cervical spine MRI report: “bulging disc, dural sac compression”, and many people think they must be “sick” or finally find the “cause”, often very anxious to know how to treat. In fact, bulging disc is not a disease, I wrote an article on my website specifically on this issue “bulging disc is not a disease”, so far is also my website to read the most hits in an article, and get everyone’s approval and praise, here again I would like to introduce you to the relevant knowledge in this regard, in order to eliminate everyone I would like to give you some more information on this topic to eliminate the fear of dural sac compression. The intervertebral disc is the basis of spinal motion, and it completes the basic motion of the spine with the two posterior synovial joints. The lower part of the upper vertebral body and the upper part of the next vertebral body are dense, forming a dense bone plate called the end plate, which forms the upper and lower ends of the intervertebral disc. The structure between the two endplates is called the intervertebral disc, and the disc is surrounded by a very strong fibrous ring, shaped like a car tire, which is attached to the endplates above and below. The annulus fibrosus occupies almost one-half of the outer radius of the intervertebral disc. The middle part is the nucleus pulposus, which is jelly-like and is enclosed in a confined cavity formed by the annulus fibrosus and the upper and lower endplates. The function of the intervertebral disc is to carry pressure, which is transmitted from the lower endplate of the upper vertebra to the upper endplate of the lower vertebra, and the intervertebral disc acts as a cushion for the pressure, and the nucleus pulposus is a jelly-like substance that distributes the pressure evenly on the endplate and the fibrous ring, which is elastic and makes the pressure cushioned, just like a car tire. The intervertebral disc can be imaginatively compared to the human body’s “shock absorption system”. As we age, the functions of various organs or systems in the human body are declining, and the degeneration of the intervertebral disc is the basis of spinal degeneration and the initiating factor of spinal degeneration. This change is uniform and consistent, resulting in a narrowing of the intervertebral space. This change is uniform and results in narrowing of the intervertebral space. Thus, the MRI shows that the signal of the nucleus pulposus is reduced and the annulus fibrosus is relaxed and expands around, while the CT and X-ray shows that the intervertebral height is reduced and the disc expands uniformly around, and the expulsion is an early manifestation of disc degeneration. Second, the structure and function of the spinal canal The spinal canal is made up of the vertebral body and the posterior part of the intervertebral disc, the vertebral arch and the yellow ligament around the spine, the most basic unit of the spine is the vertebrae or called vertebral segments, each vertebra includes the front cylindrical structure of the vertebral body and the back of the arch-shaped structure of the vertebral arch and other accessories, the vertebral body and the back of the intervertebral disc and the vertebral arch to form the vertebral foramen, the vertebrae are connected up and down, the front by the intervertebral disc connected to the adjacent two vertebral bodies, the back by the The vertebrae are connected up and down, the anterior part is connected by the intervertebral disc to the two adjacent vertebral bodies, and the posterior part is connected by the yellow ligament to the two adjacent vertebral arches, thus forming a relatively closed vertebral canal, which houses the spinal cord and the cauda equina in the lumbar spine. In this way, the spinal cord and cauda equina are like water in which they are immersed, protected by the dura mater and the strong spinal canal, so that they are not easily damaged even by external forces. When the disc degenerates, it bulges out evenly all around, and the backward bulge affects the spinal canal, causing compression of the dural sac. But is dural sac compression always a disease? To answer this question, let me use an analogy. An iron barrel with a strong plastic bag shaped like the barrel and a plastic bag filled with water in which a relatively small soft and fragile object, such as a block of tofu, is immersed, and the tofu can drift in the water to a certain extent. Now we see the iron barrel as the spinal canal, the plastic bag compared to the dura mater, the tofu compared to the nerve and spinal cord, when the iron barrel slightly deformed (like a bulging disc) first compress the plastic bag (i.e., dural sac), this is not necessarily tofu (spinal cord or nerve) compression, only the iron barrel seriously deformed (such as a serious herniated disc or trauma resulting in vertebral fracture) will be further by compressing the plastic bag (dural sac) Compression of the tofu (spinal cord or nerves) and damage to the tofu (spinal cord or nerves) is caused. From this, we can conclude that “damage to the spinal cord or nerves can only be caused by excessive compression of the dural sac to further compress the spinal cord or nerves”. Based on this conclusion, we can say that simple dural sac compression does not necessarily cause symptoms and does not necessarily lead to a diagnosis of the disease, so who makes the judgment? Of course an experienced and professional orthopedic spine doctor makes the final judgment. Judgment is based on: first, medical history; second, physical examination; and third, impact performance. Only when all three bases have the same consistent performance can a correct diagnosis be made. Finally, I would like to say that dural sac compression can only cause disease when it is quite severe, so there is no need to be overly alarmed by the presence of “dural sac compression” in the examination report.