I. Pathogenesis and characteristics The series of symptoms and signs caused by the rupture of the lumbar intervertebral disc fibrous ring and the herniated nucleus pulposus stimulating or compressing the nerve roots at the corresponding level is called lumbar intervertebral disc herniation. Lumbar disc herniation is a common disease. The incidence of lumbar disc herniation in adults in China is about 8%, but the onset of the disease is at the peak age of 30-50 years old. The adult intervertebral disc generally begins to degenerate after the age of 20, and the fibrous ring loses elasticity due to degeneration, producing a fissure. External forces aggravate the fissure and the nucleus pulposus protrudes. Most lumbar disc herniations occur in the lumbar 4, 5 and lumbar 5 sacral 1 intervertebral spaces, so clinically the symptoms and signs of lumbar 5 and sacral 1 nerve root involvement are most common. (1) Pay attention to the back and leg pain and the changes in back and leg pain before and after the onset of the disease, and the remission of back and leg pain, including the time of remission, factors affecting the remission, and whether medication is used, etc. (2)History pay attention to understand the factors related to lumbar trauma and strain, and whether it is combined with lumbar spinal stenosis. (2) Physical examination: In addition to comprehensive physical examination, patients with lower back pain should also have a detailed lumbar examination: (1) lumbar spine movement examination, including extension, flexion, lateral flexion and rotation; the range of motion and the degree of limitation should be recorded; (2) lumbar spine-related neurological examination, including posture, gait and appearance of both lower limbs; tactile sensation, pain, hot and cold sensation of both lower limbs and compare both sides; muscle strength and muscle tone of both sides; and deep and deep muscle tone. and muscle tone; deep and superficial reflexes and pathological reflexes and compare both sides. (3) Localization examination: for combined cauda equina injury or nerve root damage, localization is performed according to anatomical and physiological basis. (3) Imaging examination: front and side lumbar spine films, functional position films, lumbar spine CT films, lumbar spine MRI films. 4.Electrophysiological examination: electromyography of both lower limbs, nerve conduction velocity, etc. 5.Laboratory examination: blood, urine and stool routine, blood sugar, liver and kidney function, electrocardiogram, etc. The diagnosis of typical lumbar disc herniation can be accurately made based on medical history, symptoms, physical signs and imaging examinations, including X-ray, CT and MRI, including the diagnosis of lesion gap, protrusion direction, protrusion size and nerve compression. If there are only CT and MRI manifestations but no clinical manifestations, the disease should not be diagnosed. Although the diagnosis of lumbar disc herniation can be made through history, symptoms and signs, imaging examinations such as X-ray, CT and MRI are still required to exclude other diseases such as tumor and tuberculosis. X-rays are limited in their diagnostic role because they cannot show the intervertebral disc, but they can show other abnormalities such as tumors and tuberculosis, so this examination is necessary. Currently, the most effective test for lumbar disc herniation is MRI, while myelography is an invasive test and is less often used alone. 1, lumbar disc herniation is common in 25-45 years old, often with a history of lumbar sprain, and recurrent lumbar and leg pain is the basic symptom of the disease. The pain is relatively intense, radiating in the direction of the sciatic nerve travel, and the pain can be aggravated by coughing or forceful bowel movements or urination, and can be alleviated by bed rest. 2. The majority of patients have sciatica, and typical sciatica is a radiating pain from the lower back to the buttocks, the back of the thighs, the outer calves to the feet, and the pain is aggravated by increasing abdominal pressure when coughing. In the early stage, the pain may be hyperalgesia, and in the more severe cases, sensory dullness or numbness may occur. 3. Patients have lumbar back muscle spasm, lumbar stiffness, loss of physiological pronation, and lumbar lateral protrusion. Lumbar lordosis is a postural compensatory deformity for pain relief. If the nucleus pulposus protrudes on the lateral side of the nerve root, the upper body bends toward the healthy side and the lumbar convexity toward the affected side can relax the compressed nerve root; when the protruding nucleus pulposus is on the medial side of the nerve root, the upper body bends toward the affected side and the lumbar convexity toward the healthy side can relieve pain. 4.Most of the patients have different degrees of lumbar activity limitation, and the limitation in forward flexion is the most obvious, which is because the nucleus pulposus is aggravated in the forward flexion position, which increases the pressure on the nerve root. 5, straight leg elevation test and positive reinforcement test Patients with nerve root compression or adhesion to reduce or disappear the sliding degree, elevation within 60 ° can appear sciatica, known as a positive straight leg elevation test. The positive rate is about 90%. When the straight leg elevation test is positive, slowly lower the height of the affected limb and wait until the radiating pain disappears, then passively dorsiflex the ankle joint of the affected limb to pull the sciatic nerve, and if the radiating pain appears again, it is called a positive strengthening test. Sometimes, because of the large protruding nucleus pulposus, elevation of the healthy lower limb may also involve the affected side by pulling the dura and induce radiating pain in the affected sciatic nerve. A positive straight-leg elevation test on both sides suggests a possible central herniation. 6. Huge disc nucleus pulposus prolapsing or freeing can cause cauda equina compression syndrome. Clinical abnormalities in bowel and urine function, loss of calf muscle strength, sensory impairment of lower limbs and saddle area and sexual dysfunction may occur. In severe cases, both lower limbs are paralyzed and sphincter function is lost. 7. Changes in sensation, movement and reflexes in the innervated area of the affected nerve root can help determine the location of the protrusion. Neurological manifestations; ①Sensory abnormalities: in the case of lumbar 5 nerve root involvement, pain and tactile sensation in the anterolateral calf and medial foot are reduced; in the case of sacral 1 nerve root compression, pain and tactile sensation near the outer ankle and lateral foot are reduced. ②Decreased muscle strength: when the lumbar 5 nerve root is involved, the dorsal extension force of the ankle and toe is decreased; when the sacral 1 nerve root is involved, the plantarflexion force of the toe and foot is decreased. ③Abnormal reflexes: weakened or absent ankle reflex indicates sacral 1 nerve root compression; if the cauda equina nerve is compressed, it is decreased anal sphincter tone and weakened or absent anal reflex. 8.Imaging and electromyography examination (1)Lumbar spine frontal and lateral X-ray is mainly used to exclude other diseases of lumbar spine bones. (2) CT examination is of great value in assisting diagnosis and localization, and has more specialties in determining the presence of bony spinal stenosis, intervertebral foramen or extradural disc herniation. The combined application of this method and myelography can improve the diagnostic accuracy. (3) MRI has a slightly higher diagnostic accuracy than CT, and is better than CT in identifying nerve compression and spinal cord tumors, but does not show bony spinal canal structures as well as CT. (4) Myelography is invasive and has a similar diagnostic accuracy as CT and MRI, and is now less commonly used alone. (5) Electromyography has some reference value for local diagnosis and differential diagnosis. 9. The disease often needs to be differentiated from acute lumbar sprain, lumbar spinal stenosis, lumbar spinal tuberculosis, lumbar spondylolisthesis, nerve root sheath meningioma, cauda equina tumor and other diseases. Except for cases with obvious cauda equina nerve compression or nerve root damage, conservative treatment can be adopted first, with good results in most cases. Commonly used methods are as follows: (1) Bed rest: The acute stage should be strictly bed rest, including when eating and urinating and defecating, and most patients’ symptoms can be relieved after 3-4 weeks. (2) Traction: Its purpose is to increase the vertebral space, relieve its internal pressure, and partially return the herniated material. (3) Tui-na and massage: they have good effect on some early cases. (4) Brace and girth: mostly used as a temporary protective measure when getting up and moving around after the acute phase, but not suitable for long-term use. Surgery can be considered when the following conditions occur: (1) Non-surgical treatment for more than 3 months without significant relief of low back and leg pain symptoms. (2) Those with severe low back and leg pain that affects rest and sleep, and where conservative treatment is ineffective. (3)Those with obvious nerve damage and obvious weakening of muscle strength, such as foot drop, should be operated as early as possible. (4) Those with combined acute cauda equina injury should be operated urgently. Surgery is usually performed by posterior open disc nucleus pulposus removal. In recent years, minimally invasive surgical methods such as transvertebral discectomy or percutaneous laser lumbar discectomy have been used to treat mild to moderate intervertebral bulges and limited herniations with better results. Lumbar artificial nucleus pulposus or disc replacement is also feasible, and artificial disc replacement in the lumbar spine is not yet widely carried out in China, and is limited to large hospitals. For a few serious cases, half or full laminectomy is still needed. Early postoperative exercise of the lumbar and back muscles provides good surgical results. V. Prognosis Except for individual patients with obvious damage to the cauda equina nerve, the majority of patients suffering from lumbar disc herniation can be effectively treated and cured, and can keep on working.