What Is Foraminal Stenosis?

The intervertebral foramen is composed of the invertebral incision of the vertebra and the upper vertebra of the next vertebra. It provides holes for nerves and blood vessels to enter the spine. It is a segmental spinal nerve that exits the spinal canal, and supplies soft tissue and bone structure in the spinal canal. The portal of the blood vessels and nerve branches into the spinal canal.

Intervertebral foramen

Exam practical terms explained: It is surrounded by the upper and lower notches of adjacent vertebrae, and spinal nerves and blood vessels pass through.

It is the channel through which the spinal nerve root leaves the spinal cord. The upper and lower walls are notches of the pedicle; the front side is the lateral edge of the vertebral body, the intervertebral disc and the posterior longitudinal ligament; the rear is the joint capsule of the facet joint and part of the yellow ligament. Nerves through the intervertebral foramen are surrounded by honeycomb tissue and small blood vessels. The distance from the time when the nerve root leaves the dural sac to the intervertebral foramen is collectively called "nerve root canal". Its lateral portion is the intervertebral foramen and its medial portion is the lateral recess. The anterior wall of the lateral crypt is the posterolateral of the vertebral body and the fibrous ring, the outer wall is the medial side of the arch root, the inner side is epidural fat and the cauda equina capsule, and the posterior wall is the side of the superior articular process and the ligamentum flavum. The lateral crypts continue down into the foraminal foramen. Spinal stenosis is generally divided into congenital (primary) and acquired (native)

Intervertebral foramen

(Secondary) caused by two factors, in fact these two factors are interconnected and affect each other. The lumbar spinal canal was oval when born. However, with the development of the human body, load bearing, degenerative changes and various overloads, it has promoted its development in the direction of increasing mechanical strength. Waist to adulthood; The waists 4 to 5 are mostly triangular or shamrock-shaped and make the lumbosacral joints bear 60% to 75% of flexion and flexion. waist. ,waist. It is 15% to 20%. Although the spinal canal has increased mechanical strength, the sagittal diameter decreases. In addition, bone hyperplasia and hypertrophy of the small joints. Or the upper joint process is too long and the degeneration of the intervertebral joints is not only shortened the sagittal diameter of the spinal canal, the volume is significantly reduced, and the nerve root canal is correspondingly thin and short. Due to the reduction of the effective volume in the tube, the cauda equina and the nerve root are in a critical state. Any pathological and physiological factors that can increase the pressure in the tube, such as bone spurs, relaxation and hypertrophy of the articular capsule and the ligamentum flavum, hyperplasia of the lamina and articular processes. Degeneration of fiber loops and other changes. Increases the degree of stenosis, which directly compresses or stimulates the cauda equina and spinal nerve roots to cause lumbar spinal stenosis. According to the site and degree of spinal stenosis, it can be divided into central type, lateral recess type (root type) and mixed type. Central spinal stenosis is more common with congenital cartilage dysplasia and degenerative changes. The anteroposterior diameter and width of the spinal canal are narrow, and the sagittal diameter of the spinal canal is less than 10-12 mm. Mainly manifested as cauda equina neurogenic intermittent claudication. The lateral crypt stenosis (root canal) and intervertebral foraminal stenosis are mostly osteophyte hyperplasia or hypertrophy of the posterior outer edge of the pyramid, the sagittal diameter of the lateral crypt is less than 4mm; narrow. Mainly manifested as root neuralgia. Mixed spinal stenosis, which is a mixture of the two factors in the two types mentioned above, has both intermittent claudication and root neuralgia.