Lumbar disc herniation is one of the more common diseases, mainly because of the lumbar intervertebral disc parts (nucleus pulposus, annulus fibrosus and cartilage plate), especially the nucleus pulposus, there are varying degrees of degenerative changes, in the role of external factors, the intervertebral disc’s annulus fibrosus is ruptured, and the nucleus pulposus protrudes from the rupture place (or out) in the posterior or vertebral canal, leading to the adjacent spinal nerve roots to suffer from irritation or compression, thus generating lumbar pain As a result, a series of clinical symptoms such as lumbar pain, numbness and pain in one or both lower limbs are produced. Lumbar intervertebral disc herniation with lumbar 4-5, lumbar 5-sacral 1 the highest incidence rate, accounting for about 95%. 1, etiology (a) the basic etiology 1, lumbar intervertebral disc degenerative changes are the basic factors The degeneration of the nucleus pulposus is mainly manifested as a decrease in water content, and can be caused by water loss of vertebral joint instability, loosening, and other small-scale pathological changes; degeneration of the annulus fibrosus is mainly manifested as a reduction in the degree of toughness. 2.Injury Long-term repeated external forces cause slight damage, aggravating the degree of degeneration. 3.Weakness of the intervertebral disc’s own anatomical factors The intervertebral disc gradually lacks blood circulation after adulthood and has poor repair ability. On the basis of the above factors, some kind of triggering factors that can lead to a sudden increase in the pressure on the intervertebral disc may cause the less elastic nucleus pulposus to pass through the annulus fibrosus that has become less tough, resulting in herniation of the nucleus pulposus. 4.Genetic factors, lumbar disc herniation has been reported to be familial, and the incidence of this disease is low in people of color. Lumbosacral congenital anomalies include lumbar sacralization, sacral lumbarization, hemivertebral deformity, small joint deformity and asymmetry of articular eminence, etc. The above factors can make the lower lumbar vertebra bear the burden of the lumbar spine. The above factors can make the lower lumbar vertebrae bear the stress change, thus constituting the intervertebral disc pressure rise and easy to degenerate and injury. (ii) Triggering factors On the basis of degenerative changes in the intervertebral discs, certain factors that can induce a sudden rise in intervertebral pressure can lead to herniation of the nucleus pulposus. Common triggering factors include increased abdominal pressure, lumbar posture, sudden weight bearing, pregnancy, cold and moisture, etc. Clinical classification and pathology From the pathological changes and CT, MRI performance, combined with treatment methods can be divided into the following types. The fibrous ring is partially ruptured while the surface layer is still intact. At this time, the nucleus pulposus is limitedly elevated to the spinal canal due to pressure, but the surface is smooth. This type can be relieved or cured by conservative treatment. 2. Prolapsed type: Fiber ring is completely ruptured, and the nucleus pulposus protrudes into the spinal canal, which is only covered by the posterior longitudinal ligament or a layer of fibrous membrane, with an uneven or cauliflower-like surface, which often requires surgical treatment. 3. Prolapse free type: The ruptured and protruded intervertebral disc tissue or fragments are detached into the spinal canal or completely free. This type can not only cause nerve root symptoms, but also easily lead to cauda equina symptoms, non-surgical treatment is often ineffective. Schmorl’s node: The nucleus pulposus enters into the cancellous bone of the vertebral body through the fissure of the cartilage of the upper and lower endplates. Generally, it only causes lumbar pain without radicular symptoms, and most of the time, it does not require surgical treatment. Clinical manifestations (a) Clinical symptoms 1. Lumbago is the first symptom that appears in most patients, with an incidence rate of about 91%. As the outer layer of the fiber ring and the posterior longitudinal ligament are stimulated by the nucleus pulposus, the lower lumbar pain is produced by the sinus nerve, sometimes accompanied by hip pain. 2, lower extremity radiating pain Although high lumbar disc herniation (lumbar 2 ~ 3, lumbar 3 ~ 4) can cause femoral neuralgia, but the clinical rare, less than 5%. The vast majority of patients are lumbar 4 ~ 5, lumbar 5 ~ sacral 1 interspace herniation, manifested as sciatica. Typical sciatica is a radiating pain from the lower lumbar region to the buttocks, the back of the thighs, the lateral calf and up to the foot, and the pain is exacerbated by increased abdominal pressure such as sneezing and coughing. The radiating pain is mostly on one side of the limb, and only very few people with central or paracentral herniated nucleus pulposus show symptoms in both lower limbs. There are three reasons for sciatica: ① the ruptured intervertebral disc produces chemical stimulation and autoimmune reaction so that chemical inflammation occurs in the nerve root; ② the protruding nucleus pulposus compresses or stretches the nerve root that has been inflamed, so that the venous return of it is blocked, which further aggravates the oedema and makes it sensitive to the pain; ③ the compressed nerve root ischemia. The above three factors are interrelated and mutually aggravating. 3, cauda equina symptoms to the posterior protruding nucleus pulposus or prolapse, free intervertebral disc tissue compression of the cauda equina, its main manifestations for bowel obstruction, perineum and perianal sensory abnormalities. In severe cases, symptoms such as uncontrolled urination and defecation and incomplete paralysis of both lower limbs may occur, which are rare clinically. (B) Signs of lumbar disc herniation 1. General signs (1) Lumbar scoliosis is a postural compensatory deformity for pain relief. Depending on the relationship between the herniated nucleus pulposus and the nerve root, the spine bends to the healthy side or to the affected side. If the herniated nucleus pulposus is located on the inner side of the spinal nerve root, bending the spine to the affected side can reduce the tension of the spinal nerve root, so the lumbar spine bends to the affected side; on the contrary, if the herniated material is located on the outer side of the spinal nerve root, the lumbar spine bends more to the healthy side. (2) Restriction of lumbar activities Most patients have different degrees of restriction of lumbar activities, which is especially obvious in the acute stage, among which the restriction of anterior flexion is the most obvious, because anterior flexion can further promote the nucleus pulposus to move backward, and increase the pull on the compressed nerve root. (3) Pressure, percussion and spasm of the sacrospinous muscles The sites of pressure and percussion basically coincide with the diseased intervertebral space, and 80% to 90% of the cases are positive. Knocking pain is obvious at the spinous process, which is caused by knocking and vibrating the lesion. Pressure points are mainly located in the 1cm of the paravertebral region, and radiating pain along the sciatic nerve may occur. About 1/3 of patients have lumbar sacrospinal muscle spasm. 2.Special signs (1)Straight leg raising test and strengthening test The patient lies on the back, extends the knee, and passively raises the affected limb. In normal people, the nerve root has a sliding degree of 4mm, and the lower limb is elevated to 60°～70° before feeling the discomfort of N fossa. In patients with lumbar disc herniation, nerve root compression or adhesion reduces or disappears the sliding degree, and sciatica can be seen when the limb is elevated to 60° or less, which is known as a positive straight-leg elevation test. In positive patients, slowly lowering the height of the affected limb, to be radiating pain disappears, then passive flexion of the affected ankle joint, once again induced radiating pain is called positive strengthening test. Sometimes, because of the large nucleus pulposus, elevating the healthy side of the lower limb can also pull the dura mater to induce the affected sciatic nerve to produce radiating pain. (2) Femoral nerve pulling test: The patient is placed in the prone position, and the knee joint of the affected limb is completely straightened. The examiner will straighten the lower limb elevated, so that the hip joint is in the hyperextension position, when hyperextension to a certain degree of pain in the femoral nerve distribution area in front of the thigh, it is positive. This test is mainly used to examine patients with lumbar 2-3 and lumbar 3-4 herniated intervertebral discs. 3.Neurological manifestations (1) Sensory impairment Depending on the location of the affected spinal nerve root, the sensory abnormality of the innervated area may occur. The positive rate is more than 80%. In the early stage, skin sensation allergy is often manifested, and numbness, tingling and hypesthesia gradually appear. Because of the involvement of nerve roots to a single section of unilateral, so the range of sensory impairment is small; but if the cauda equina is involved (central type and central paracentral type), the range of sensory impairment is more extensive. (2) Decrease in muscle strength 70%～75% of patients have decreased muscle strength, lumbar 5 nerve root involvement, ankle and toe dorsal extension decreased, sacral 1 nerve root involvement, toe and foot plantar flexion decreased. (3) Reflex changes are also one of the typical signs of this disease. Involvement of lumbar 4 nerve roots may cause knee-jerk reflex disorder, which is active in the early stage and then rapidly becomes hyporeflexia, while damage to lumbar 5 nerve roots has no effect on the reflexes. The Achilles tendon reflex is impaired in sacral 1 nerve root involvement. Reflex changes are of greater significance to the localization of the affected nerves. X-ray film of lumbar spine can not directly react to the existence of disc herniation, but sometimes the X-ray film can see the narrowing of the intervertebral space, vertebral body edge hyperplasia and other degenerative changes, which is a kind of indirect hint, and some patients can have spinal deviation and scoliosis. In addition, X-ray film can find out whether there are tuberculosis, tumors and other bone diseases, which has important significance in differential diagnosis. 2.CT examination can clearly show the location, size and shape of the herniated disc and the displacement of the nerve root and dural sac, meanwhile, it can also show the hypertrophy of the vertebral plate and ligamentum flavum, hyperplasia and hypertrophy of the small joints, and stenosis of the vertebral canal and lateral fossa, which is of great diagnostic value for this disease and has been commonly used. 3.Magnetic resonance imaging (MRI) MRI has no radioactive damage and is of great significance to the diagnosis of lumbar disc herniation, which can comprehensively observe whether the lumbar discs are diseased or not, and through the sagittal images at different levels and the transverse images of the involved discs, it can clearly show the morphology of the discs protruding and their relationship with the dural sacs and the nerve roots and other peripheral tissues, and it can also identify the existence of other space-occupying lesions in the vertebral canal. In addition, it can identify the presence of other space-occupying lesions in the spinal canal. However, it is not as good as CT examination in showing whether the herniated disc is calcified or not. Electrophysiologic tests (electromyography, nerve conduction velocity and evoked potentials) can help determine the extent of nerve damage and observe the effect of treatment. Laboratory tests are mainly used to exclude some diseases and play the role of differential diagnosis. Diagnosis The diagnosis of typical cases, combined with history, physical examination and imaging, is generally not difficult, especially in today’s CT and MRI technology is widely used. If there are only CT and MRI manifestations without clinical symptoms, the disease should not be diagnosed. 6. Treatment 1. Non-surgical treatment Most patients with lumbar disc herniation can be relieved or cured by non-surgical treatment. The principle of treatment is not to return the degenerated and protruded intervertebral disc tissue to its original position, but to change the relative position of the intervertebral disc tissue and the compressed nerve root or partially retract it, to reduce the pressure on the nerve root, to loosen the adhesion of the nerve root, to eliminate the inflammation of the nerve root, so as to relieve the symptoms. Non-surgical treatment is mainly suitable for: ① young, first attack or short duration of the disease; ② mild symptoms, symptoms can be relieved by themselves after rest; ③ no obvious stenosis of the spinal canal in the imaging examination. (1) Absolute bed rest When the first attack occurs, it should be strictly bed rest, emphasizing that neither bowel movement nor urination should be out of bed or sitting up. After 3 weeks of bed rest, you can get up and move around under the protection of wearing a waist cuff, and do not do any bending over to hold things within 3 months. This method is simple and effective, but more difficult to adhere to. After relief, the lumbar back muscle exercise should be strengthened to reduce the chance of recurrence. (2) Traction therapy The use of pelvic traction can increase the width of the intervertebral space, reduce the internal pressure of the intervertebral disc, the herniated portion of the intervertebral disc is retracted, and reduce the irritation and compression on the nerve root, which needs to be carried out under the guidance of a professional doctor. (3) Physiotherapy and massage can relieve muscle spasm and reduce the pressure within the intervertebral disc, but note that violent massage can lead to aggravation of the condition, and caution should be taken. (4) Corticosteroid epidural injection Corticosteroid is a long-acting anti-inflammatory agent that can reduce inflammation and adhesion around the nerve root. Generally, long-acting corticosteroid preparation + 2% lidocaine is used for epidural injection, once a week, 3 times for a course of treatment, and another course of treatment can be used after 2-4 weeks. (5) Nucleus pulposus chemical dissolution method Using collagenase or papain, injected into the intervertebral disc or between the dura mater and the protruding nucleus pulposus, to selectively dissolve the nucleus pulposus and annulus fibrosus without damaging the nerve root, in order to reduce the pressure in the intervertebral disc or make the protruding nucleus pulposus smaller so as to relieve the symptoms. However, this method has the risk of allergic reaction. 2. Percutaneous Nucleotomy / Nucleus Pulposus Laser Gasification By entering the intervertebral space under X-ray surveillance with special instruments, part of the nucleus pulposus is crushed and suctioned out or gasified by laser, so as to reduce the pressure in the intervertebral disc to alleviate the symptoms, which is suitable for patients with bulging or mild herniation, and is not suitable for patients with combined lateral saphenous stenosis or those with significant herniation or those whose nucleus pulposus has already been dislodged into the vertebral canal. 3, surgical treatment (1) indications for surgery ① history of more than three months, strict conservative treatment is ineffective or conservative treatment is effective, but often recurring and severe pain; ② the first attack, but the pain is severe, especially in the lower limbs, the patient is difficult to move and sleep, in a forced position; ③ combined with the cauda equina nerve compression manifestations; ④ the emergence of a single nerve root paralysis, accompanied by muscular atrophy, muscle weakness; ⑤ combined with the spinal canal stenosis. ⑤ Combined with spinal canal stenosis. (2) Surgical method: Partial removal of the vertebral plate and synchondrosis through back incision, or discectomy through the intervertebral plate space. For central herniated disc, after laminectomy, extradural or intradural discectomy is performed. In combination with lumbar instability and lumbar spinal stenosis, spinal fusion is required at the same time. In recent years, minimally invasive surgical techniques such as microdiscectomy, microendoscopic discectomy, and percutaneous intervertebral foraminoscopic discectomy have reduced surgical damage and achieved good results. 7.Prevention Lumbar disc herniation is caused by accumulation of injuries on the basis of degeneration, and accumulation of injuries will aggravate the degeneration of intervertebral discs, therefore, the focus of prevention is to reduce accumulation of injuries. Normally, you should have a good sitting posture, and the bed should not be too soft when you sleep. Long-term ambulatory workers need to pay attention to the height of the table and chair, and change the posture on a regular basis. Occupational work requires frequent bending movements, should regularly stretch, chest activities, and the use of a wide belt. Should strengthen the lumbar back muscle training, increase the intrinsic stability of the spine, the long-term use of waist circumference, especially need to pay attention to the lumbar back muscle exercise, in order to prevent disuse of muscle atrophy brought about by the adverse consequences. If you need to bend down to get something, it is best to use hip flexion, knee flexion squatting mode, to reduce the pressure on the lumbar intervertebral disc posterior.