Lumbar spine While the spinal canal (spinal spinal canal) has an oval structure, especially in the upper lumbar region, it shows a more triangular structure as you go down to the lower levels. Especially at the L5 level, the spinal cord canal is in the shape of a cloverleaf and there is a distinct nerve root canal appearance on the sides. Stenosis in the spinal canal causes compression of the dural sac, cauda fibers and nerve roots. Waist stenosis is divided into 4 groups according to its location. According to this;
1. Central spinal cord canal stenosis,
2. Nerve root canal stenosis (Lateral Recess Syndrome),
3. Nerve exit channel entrance stenosis
4. Nerve exit channel exit stenosis (Far lateral stenosis).
The spinal canal, the nerve root canal and the intervertebral foramen, all or each of them, may narrow as a result of changes in the surrounding bone and connective tissues. The narrowing may occur in the middle or on the sides, at a single level, or at multiple levels. Degenerative changes seen in the spine with advancing age are called spondylosis. Disc aging, which begins with the replacement of Type 2 collagen with Type 1 collagen and a decrease in the amount of proteoglycans, leads to thickening of the bone and connective tissue around the spinal canal, nerve root canal and intervertebral foramen. As the volume of the intervertebral disc or discs decreases, more load is placed on the spinal joint extensions, and these extensions take a more horizontal shape. The yellow ligament (ligamentum flavum) located at the back becomes thicker. The removal of the periosteum around the spinal canal and nerve root canal stimulates osteophyte formation, and osteophytes are formed as a result of endochondral ossification of the external attachment points of the annulus. Osteophytic bone extensions may cause pressure on their own or may surround the spinal canal. Osteophytes can be located in the midline, causing central stenosis, and can be located in the lateral areas, causing lateral stenosis. Normal extradural fatty tissue within the canal is replaced by a fibrous structure. The nerve root canal is located along the pedicle just before the neural foramen. It has the vertebral body in front and the upper joint extension behind it. Superior articular facet hypertrophy nerve loss It causes pressure and symptoms to occur. The anterior wall of the intervertebral foramen is formed by the intervertebral disc, the lateral wall by the facet joint and ligamentum flavum, and the posterior wall by the lamina. As a result of disc degeneration, bone structures and ligament hypertrophy, there is narrowing of the intervertebral foramen. In lumbar canal stenosis, some bone structures around the canal thicken and the joints turn inwards and downwards. As a result, the shape of the spinal canal changes and it takes on the appearance of a clover leaf. If a herniated disc is added to the problem at this stage, the stenosis will increase even more. Additionally, instability may develop in the spine and retrolissthesis, spondylolisthesis or lateral slip may develop. Ischemia of the cauda equina and nerve roots and friction neuritis may develop within the narrowed and increased pressure spinal canal and nerve root canal. This situation is an important factor in the progression of the disease. Since the narrowing process of the canal develops very slowly, in a group of patients, although the canal is very narrow, there may be no or very few neurological indicators of this stenosis. If the spinal canal is already narrow at the beginning of these developments, clinical findings and symptoms may appear at a very early age. Due to spondylotic and arthritic development, the ability of the spine to bear weight is very rare. In measurements made from the middle of the lumbar canal, a measurement between 10-13 mm is critical, and a decrease below 10 mm is an absolute sign of stenosis. Calcification in the spine and narrowing of the spinal canal, lumbar canal stenosis, often develops between the 3/4 and 4/5 vertebrae in the waist.
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