What is a Lumbar Herniated Disc?

Lumbar disc herniation is one of the more common diseases, mainly due to the various degrees of degenerative changes in the various parts of the lumbar disc (nucleus pulposus, fibrous rings and cartilage plates), especially the nucleus pulposus, under the influence of external forces. The fibrous ring of the intervertebral disc is ruptured, and the nucleus pulposus tissue protrudes (or prolapses) from the rupture to the back or in the spinal canal, causing adjacent spinal nerve roots to be stimulated or oppressed, resulting in pain in the waist, numbness and pain in one or two lower limbs Wait for a series of clinical symptoms. The incidence of lumbar disc herniation is highest in lumbar 4-5 and lumbar 5-5, accounting for about 95%.

Basic Information

Visiting department: orthopedics
Common locations: Lumbar spine

Common causes: Caused by lumbar disc disease or trauma
Common symptoms: Waist pain, numbness or pain in one or both lower limbs

Causes of lumbar disc herniation

1. Degenerative changes of the lumbar disc are the basic factors

The degeneration of the nucleus pulposus mainly manifests as a decrease in water content, and can lead to small-scale pathological changes such as vertebral instability and looseness due to dehydration; degeneration of the fibrous ring mainly manifests as a decrease in toughness.

2. damage

Repeated external forces for a long time caused slight damage and aggravated the degree of regression.

3. Weak points of intervertebral disc anatomical factors

The intervertebral disc gradually lacks blood circulation after adulthood, and its repair ability is poor. Based on the above factors, a certain inducing factor that can cause a sudden increase in pressure on the disc, that is, may cause the less elastic nucleus pulposus to pass through the fibrous ring that has become less tenacious, causing the nucleus pulposus to protrude.

4. Genetic factors

Familial onset of lumbar disc herniation has been reported.

5. Congenital lumbosacral anomalies

Including lumbar vertebralization, iliac vertebralization, hemivertebral deformity, facet joint deformity, and asymmetry of articular processes. The above factors can change the stress experienced by the lower lumbar vertebrae, which constitutes an increase in internal disc pressure and is prone to degeneration and injury.

6. Inducing factors

Based on the degenerative changes of the intervertebral disc, a certain factor that can induce a sudden increase in intervertebral space pressure can cause the nucleus pulposus to protrude. Common predisposing factors are increased abdominal pressure, waist posture, sudden weight bearing, pregnancy, cold and damp.

Clinical classification and pathology of lumbar disc herniation

From pathological changes and CT and MRI manifestations, combined with treatment methods can be classified as follows.

Bulging

The annulus fibrosus was partially ruptured, and the surface layer was still intact. At this time, the nucleus pulposus was limited to bulge into the spinal canal due to pressure, but the surface was smooth. Most of this type can be relieved or cured by conservative treatment.

2.Outstanding type

The annulus fibrosus is completely ruptured, the nucleus pulposus protrudes toward the spinal canal, and is covered only by the posterior longitudinal ligament or a layer of fibrous membrane.

3. Prolapse free type

The ruptured disc tissue or fragments are dislodged into the spinal canal or completely free. This type can not only cause nerve root symptoms, but also easily cause cauda equina symptoms. Non-surgical treatment is often ineffective.

4.Schmorl nodule

The nucleus pulposus enters the vertebral cancellous bone through the fissures in the upper and lower endplate cartilage. Generally, it only has low back pain, no nerve root symptoms, and usually does not require surgery.

Clinical manifestations of lumbar disc herniation

(A) symptoms

Back pain

It is the first symptom of most patients, with an incidence of about 91%. Because the outer layer of the fibrous ring and the posterior longitudinal ligament are stimulated by the nucleus pulposus, the sinus vertebral nerves cause lower back pain, which may sometimes be accompanied by hip pain.

2. Radiation pain in lower limbs

Although high lumbar disc herniation (lumbar 2-3, waist 3-4) can cause femoral neuralgia, it is rare in clinical practice, less than 5%. The vast majority of patients have a lumbar 4 to 5 and a lumbar 5 to sacral 1 with prominent sciatica. Typical sciatica is radiating pain from the lower back to the buttocks, the back of the thighs, the outside of the lower legs, and down to the feet. The pain can be exacerbated by increased abdominal pressure such as sneezing and coughing. The limbs with radiating pain are mostly on one side, and only a few of the central or paracentral nucleus pulposus show bilateral lower limb symptoms. There are three reasons for sciatica: chemical stimulation of the ruptured intervertebral disc and autoimmune reactions cause chemical inflammation of the nerve roots; the prominent nucleus pulposus compresses or stretches the nerve roots that have been inflamed, which hinders the venous return of veins, further Aggravating edema makes the sensitivity to pain increased; ischemia of the compressed nerve root. The above three factors are related to each other and are aggravating factors to each other.

3. Cauda equina symptoms

The nucleus pulposus or prolapse that protrudes to the rear and the free intervertebral disc tissue compresses the cauda equina, which is mainly manifested as dysuria, dysuria, and perineal and perianal abnormalities. In severe cases, symptoms such as uncontrollable bowel movements and incomplete paralysis of the lower limbs may occur, which are rare in clinical practice.

(Two) physical signs

General signs

(1) Lumbar scoliosis is a postural compensation deformity to reduce pain. The relationship between the protruding part of the nucleus pulposus and the nerve root is different, and the spine is bent to the healthy side or the affected side. If the nucleus pulposus is located inside the spinal nerve root, the spine bends to the affected side to reduce the tension of the spinal nerve root, so the lumbar spine bends to the affected side. Conversely, if the protrusion is located outside the spinal nerve root, the lumbar spine bends to the healthy side.

(2) Restricted lumbar motion Most patients have varying degrees of restricted lumbar motion, especially in the acute phase. The limitation of previous flexion is the most obvious, because the forward flexion can further promote the displacement of the nucleus pulposus and increase Pull on compressed nerve roots.

(3) The site of tenderness, palatalgia, and diaphragmatic spasm of tenderness and palatalgia is basically consistent with the diseased intervertebral space, and it is positive in 80% to 90% of cases. Pain pain is obvious at the spinous process, which is caused by tapping the vibration lesion. The tenderness point is mainly located 1cm near the vertebra, and there may be radiation pain along the sciatic nerve. About one-third of patients have spasms of the iliac spine muscles.

2. Special signs

(1) Patients with straight leg elevation test and strengthening test were supine, knees extended, and the affected limb was passively elevated. Normal human nerve roots have a 4mm sliding degree, and the lower extremities are raised to 60 ° ~ 70 ° before they feel discomfort in the popliteal fossa. In patients with lumbar disc herniation, the compression or adhesion of the nerve root reduces or disappears the slip, and sciatica can occur within 60 °, which is called a positive leg elevation test. In positive patients, slowly lowering the height of the affected limb until the radiation pain disappears, and then passively flexing the affected ankle joint to induce radiation pain again is called a positive test. Sometimes due to the large nucleus pulposus, raising the lower limb of the healthy side can also pull the dura mater to induce radiating pain in the sciatic nerve of the affected side.

(2) The femoral nerve traction test was performed in the prone position, and the knee joint of the affected limb was completely straightened. The examiner will raise the straight lower limbs so that the hip joint is in an overextended position. When the overextension reaches a certain degree, pain in the femoral nerve distribution area in front of the thigh is positive. This test is mainly used to examine patients with lumbar discs 2 to 3 and lumbar discs 3 to 4.

3. Nervous system performance

(1) Paresthesia in the innervated area of the spinal nerve roots depending on the site of the affected spine. The positive rate is over 80%. In the early stages, skin sensitization is common, and numbness, tingling, and sensation gradually develop. Because the affected nerve roots are mostly one-sided and unilateral, the range of sensory disturbance is small; however, if the cauda equina is involved (central and paracentral type), the range of sensory disturbance is wider.

(2) 70% to 75% of patients with decreased muscle strength showed muscle strength decline. When the lumbar 5 nerve root was involved, the ankle and toe dorsiflexion decreased. When the sacroiliac nerve root was involved, toe and plantar flexion decreased.

(3) The change of reflex is also one of the typical signs that the disease is prone to occur. When the lumbar 4 nerve root is involved, a knee jump reflex disorder may appear, which is active early and then quickly becomes hyporeflexia. When the lumbar 5 nerve root is damaged, it has no effect on the reflex. Achilles tendon reflex disorder when the phrenic nerve root is involved. The change in reflexes is of great significance for the localization of affected nerves.

Lumbar disc herniation

1. Plain lumbar X-ray film

Simple plain radiographs cannot directly reflect the presence of intervertebral disc herniation, but sometimes degenerative changes such as narrowing of the intervertebral space and hyperplasia of the vertebral body are sometimes seen on the radiographs, which is an indirect indication. Some patients may have spinal deflection and spinal side Convex. In addition, plain radiographs can detect the presence or absence of bone diseases such as tuberculosis and tumors, which is of important diagnostic significance.

2.CT inspection

It can clearly show the position, size, morphology, and nerve root of the disc herniation, and the displacement of the dural sac. It can also show the laminar and ligamentum ligament hypertrophy, small joint hypertrophy, spinal canal and lateral crypt narrowing. In other cases, it has great diagnostic value for this disease, and it has been widely used.

3. Magnetic resonance (MRI) examination

MRI has no radiation damage and is of great significance in the diagnosis of lumbar disc herniation. MRI can comprehensively observe whether the lumbar intervertebral disc is diseased, and clearly show the shape of the disc herniation and its relationship with the surrounding tissues such as the dural sac and nerve roots through sagittal images of different levels and cross-section images of the involved discs. In addition, it can identify the presence of other occupying lesions in the spinal canal. However, it is not as good as CT to show whether the protruded disc is calcified.

4. Other

Electrophysiological examination (electromyography, nerve conduction velocity, and evoked potential) can help determine the extent and extent of nerve damage and observe the effect of treatment. Laboratory tests are mainly used to exclude some diseases and play a role in differential diagnosis.

Diagnosis of lumbar disc herniation

The diagnosis of typical cases, combined with medical history, physical examination and imaging examination, is generally more difficult, especially today when CT and magnetic resonance technology are widely used. If there are only CT and MRI findings without clinical symptoms, the disease should not be diagnosed.

Treatment of lumbar disc herniation

Non-surgical therapy

Most patients with lumbar disc herniation can be relieved or cured by non-surgical treatment. The treatment principle is not to restore the degenerated disc tissue to its original position, but to change the relative position or partial resorption of the disc tissue and the compressed nerve root, reduce the pressure on the nerve root, loosen the adhesion of the nerve root, and eliminate the nerve root. Inflammation, thereby relieving symptoms. Non-surgical treatment is mainly applicable to: young, first-onset or short-term disease; mild symptoms, symptoms can be relieved after rest; no obvious spinal stenosis on imaging examination.

(1) In the first episode of absolute bed rest , bed rest should be strictly carried out, emphasizing that neither urine nor urination should get out of bed or sit up in order to have a better effect. After 3 weeks of rest in bed, you can wear the waist to protect yourself from getting up and do not bend or hold objects within 3 months. This method is simple and effective, but it is more difficult to adhere to. After remission, strengthen the lower back muscles to reduce the chance of recurrence.

(2) Traction treatment uses pelvic traction, which can increase the width of the intervertebral space, reduce the internal pressure of the intervertebral disc, and receive the protrusion of the intervertebral disc to reduce the stimulation and compression of nerve roots, which requires the guidance of a professional doctor.

(3) Physical therapy, massage and massage can alleviate muscle spasm and reduce the pressure in the intervertebral disc, but pay attention to violent massage and massage can lead to aggravation of the condition, and should be cautious.

(4) Supportive treatment can try to use glucosamine sulfate and chondroitin sulfate for supportive treatment. Glucosamine sulfate and chondroitin sulfate are used clinically to treat osteoarthritis in various parts of the body. These chondroprotective agents have a certain degree of anti-inflammatory and anti-chondrogenic effect. Basic research has shown that glucosamine can inhibit the production of inflammatory factors by spinal cord nucleus pulposus cells and promote the synthesis of glycosaminoglycans, the components of the disc cartilage matrix. Clinical studies have found that injecting glucosamine into the disc can significantly reduce lower back pain caused by degenerative disc disease and improve spinal function. Case reports suggest that oral glucosamine sulfate and chondroitin sulfate can reverse the degenerative changes of the disc to a certain extent.

(5) Corticosteroids Epidural injection of corticosteroids is a long-acting anti-inflammatory agent that can reduce inflammation and adhesions around nerve roots. Generally, a long-acting corticosteroid preparation + 2% lidocaine is used for epidural injection, once a week, 3 times as a course of treatment, and another course can be used after 2 to 4 weeks.

(6) Nucleus pulposus chemical dissolution method uses collagenase or papain to inject into the intervertebral disc or between the dura mater and the prominent nucleus pulposus to selectively dissolve the nucleus pulposus and the fibrous ring without damaging the nerve root to reduce the pressure in the intervertebral disc. Or make the prominent nucleus pulposus smaller to relieve symptoms. However, this method has the risk of producing an allergic reaction.

2. Percutaneous nucleus pulposcopy / nucleus pulposus laser vaporization

Enter the intervertebral space through X-ray monitoring with special equipment, suck out part of the nucleus pulposus or laser vaporize, so as to reduce the pressure in the intervertebral disc to relieve the symptoms. It is suitable for patients with bulging or slightly protruding, not suitable for the combined side Patients with narrow crypts or already prominent protrusions and those with nucleus pulposus prolapsed.

3. Surgical treatment

(1) Indications for surgery Patients with a medical history of more than three months who have failed strict conservative treatment or are effective in conservative treatment, but often relapse and have severe pain; The first episode, but the pain is severe, especially the symptoms of the lower limbs are obvious, and it is difficult for the patient to move and fall asleep , In a forced posture; combined with cauda equina compression; single nerve root paralysis, accompanied by muscle atrophy, decreased muscle strength; with spinal canal stenosis.

(2) Surgical methods: A posterior lumbar and back incision, partial laminectomy and articular process resection, or discectomy through the laminar space. Central disc herniation, after laminectomy, the epidural or intradural discectomy. Patients with lumbar spinal instability and lumbar spinal stenosis need to undergo spinal fusion at the same time.

In recent years, minimally invasive surgical techniques, such as microendoscopic discectomy, microendoscopic discectomy, and percutaneous discectomy, have reduced surgical damage and achieved good results.

Prevention of lumbar disc herniation

Lumbar disc herniation is caused by accumulated injuries on the basis of degenerative changes, which can aggravate disc degeneration, so the focus of prevention is to reduce accumulated injuries. Always have a good sitting position, the bed should not be too soft when sleeping. Long-term desk workers need to pay attention to the height of tables and chairs and change their posture regularly. Those who need to bend down frequently in professional work should regularly stretch their waists and chests, and use a wide belt. Should strengthen the back muscle training, increase the inherent stability of the spine, long-term use of waist circumference, in particular, need to pay attention to the back muscle exercise to prevent the adverse effects of atrophic muscle atrophy. If you need to bend down to take things, it is best to use hip flexion and knee flexion to reduce the pressure on the back of the lumbar disc.