Lumbar Herniated Disc

Overview

Low back pain is a common complaint, affecting around 80% of the population at some point in their lives. The most prevalent cause of low back pain is intervertebral degeneration, which leads to lumbar disc herniation and degenerative disc disease.

 

What Are Herniated Discs?

A herniated disc (also known as a bulged, slid, or ruptured disc) is a piece of the disc nucleus that has pushed through a tear or rupture in the annulus into the spinal canal. Discs that herniate are frequently at an early stage of degeneration. The space in the spinal canal is insufficient for the spinal nerve and the displaced herniated disc fragment. Because of this displacement, the disc pushes on spinal nerves, causing discomfort that can be severe.

Herniated discs can occur anywhere along the spine. Herniated discs most commonly occur in the lower back (lumbar spine), although they can also develop in the neck (cervical spine). The location of pain is determined by which section of the spine is afflicted.

 

Anatomy of the Spinal Column

To better comprehend how a herniated disc arises, basic knowledge of spine anatomy and, more particularly, the sections of the spine involved is beneficial. The intervertebral discs are the cushions between each vertebra in your spine that function as shock absorbers. Each vertebra has one disc between them. Each disc contains a tough outer ring of fibers known as the annulus and a soft, jelly-like interior known as the nucleus pulposus.

The lumbar spine is made up of five vertebrae and intervertebral discs that form a lordotic curvature. The gap where the spinal nerves leave is formed by the intervertebral discs and the laminae, pedicles, and articular processes of surrounding vertebrae. The intervertebral discs are made up of three parts: an inner nucleus pulposus (NP), an outer annulus fibrosus (AF), and cartilaginous endplates that connect the disc to the vertebrae.

The nucleus pulposus is a gel-like substance made up of around 80% water and the balance of type 2 collagen and proteoglycans. The bigger aggrecan, which is important for holding water within the nucleus pulposus, is among the proteoglycans. It also contains versican, which binds to hyaluronic acid. This hydrophilic matrix is responsible for the intervertebral disc's height.

The nucleus pulposus is surrounded by a ring-shaped tissue called the annulus fibrosus. It is composed of highly organized fibrous connective tissue composed of 15 to 25 stacked sheets of mainly collagen lamellae interspersed with proteoglycans, glycoproteins, elastic fiber, and connective tissue cells that release these extracellular matrix products. The inner annulus fibrosus is largely formed of type 2 collagen, whereas the outer annulus fibrosus is mostly made of type 1 collagen.

A herniated disc develops when the outer fibers (the annulus) of the intervertebral disc are destroyed and the soft interior material of the nucleus pulposus ruptures out of its usual space. The nucleus pulposus material can press into the spinal canal if the annulus rips near the spinal canal.

 

Lumbar Herniated Disc Risk Factors

Herniated discs can develop in children, but it is uncommon. Young and middle-aged people are more likely to have a genuine herniated nucleus pulposus. The degenerative changes that occur in the spine as people age actually make them less likely to suffer a real herniated disc.

Discs can rupture quickly if too much pressure is applied to them all at once. Falling from a ladder and landing in a sitting position, for example, can produce a significant amount of stress across the spine. If the force is great enough, either a vertebra or a disc might fracture or shatter. Bending over puts a lot of pressure on the discs between the vertebrae. Bending and attempting to move something too heavy might cause a disc to burst.

Discs can also rupture with a modest amount of force, which is mainly due to weakening of the annulus fibers of the disc from repetitive traumas that accumulate over time. As the annulus weakens, you may raise or bend in such a way that you put too much pressure across the disc. The weakening disc ruptures when you are performing something that would not have been an issue five years ago. This is the natural aging process of the spine.

A herniated disc produces complications in two ways. For starters, the material that has ruptured into the spinal canal from the nucleus pulposus might put pressure on the spinal canal's nerves. There is additional evidence that the substance in the nucleus pulposus causes chemical irritation of the nerve roots. Both pressure on the nerve root and chemical irritation can cause issues with how the nerve root functions. The two together can produce discomfort, weakness, and/or numbness in the portion of the body where the nerve normally travels. 

 

How a Disc Herniates?

Lumbar disc herniation is caused by several changes in the intervertebral disc, including decreased water retention in the nucleus pulposus, an increased type 1 collagen ratio in the nucleus pulposus and inner annulus fibrosus, collagen and extracellular material destruction, and an increase in the activity of degrading systems such as matrix metalloproteinase expression, apoptosis, and inflammatory pathways. As a result, the projecting nucleus pulposus on the departing nerve causes a local increase in inflammatory chemokines and mechanical compression.

Localized back pain is produced by the pressure placed by the herniated disc on the longitudinal ligament and the irritation generated by the local inflammation. Lumbar radicular pain occurs when disc material presses on or touches the thecal sac or lumbar nerve roots, causing ischemia and inflammation. The annulus fibrosus is sensitive to herniation because it is thinner on the posterolateral side and lacks support from the posterior longitudinal ligament. A posterolateral herniation is more likely to result in nerve root compression due to the close proximity to the nerve root.

The narrowing of the space available for the thecal sac in LDH is caused by several factors, including disc protrusion through an intact annulus fibrosus, nucleus pulposus extrusion through the annulus fibrosus while maintaining disc space continuity, or obliteration of disc space continuity and sequestration of free fragments.

 

Lumbar Herniated Disc Symptoms

In order to evaluate a patient with suspected lumbar disc herniation, a complete history and physical examination are required. The following are the primary signs and symptoms:

• Radicular pain
• Low back pain
• Sensory abnormalities at the lumbosacral nerve roots distribution
• Weakness at the lumbosacral nerve roots distribution
• Limited trunk flexion
• Pain exacerbation with straining, coughing, and sneezing
• Pain intensified in a seated position, as the pressure applied to the nerve root is increased by approximately 40%

Questions concerning the severity of the pain and its influence on the patient's activity must be included in the history. It is critical to understand the mechanism of harm. The doctor must inquire about current or previous therapies, urine or fecal incontinence, saddle anesthetic, a history of cancer, inflammatory disorders, systemic infection, immunosuppression, and medication usage. Fever, night sweats, unexplained weight loss, lack of appetite, acute pain, and vertebral body point discomfort should all be checked as red flag indicators of an underlying infection, inflammatory illness, or cancer.

If the lumbar disc herniation is producing radiculopathy, a comprehensive neurological examination might assist to pinpoint the amount of herniation. A thorough understanding of the architecture of nerve roots and lumbar disc herniations would allow for an accurate assessment of the clinical signs associated with this illness. The radiculopathy caused by LDH differs depending on the type of herniation and the level at which the herniation occurred.

A cremasteric reflex is used to examine the outflow of the L1 nerve root at the L1-L2 foramina (male). A herniated disc generates discomfort when it is compressed, and sensory loss in the inguinal area seldom causes weakness in hip flexion.

The L2-L3 and L3-L4 foramina are where the L2 and L3 nerve roots escape. Sneezing, coughing, or straightening of the legs aggravates the symptoms.

The L4 nerve root exits through the L4-L5 foramina. A patellar reflex is used to test L4. A herniated disc produces back discomfort that spreads into the anterior thigh and medial side of the leg, as well as sensory loss in the same distribution, weakness in hip flexion and adduction, weakness in knee extension, and a reduced patellar reflex. 

The L5 nerve root exits through the L5-S1 foramina. When a herniated disc compresses the spine, it causes back discomfort that spreads into the buttock, lateral thigh, lateral calf, dorsum of the foot, and great toe. The web area between the big toe and second toe, the dorsum of the foot, and the lateral calf all have sensory loss. Hip abduction, knee flexion, foot dorsiflexion, big toe dorsiflexion, foot inversion, and eversion are all weak. Patients have a reduced semitendinosus/semimembranosus reflex. Walking on the heels is difficult due to a lack of dorsiflexion in the feet. Chronic L5 radiculopathy can induce atrophy of the anterior leg's extensor digitorum brevis and tibialis anterior.

The Achilles reflex detects the outflow of the S1 nerve root at the S1-S2 foramina. When a herniated disc compresses it, it causes sacral or buttock discomfort that spreads into the posterolateral thigh, calf, plantar or lateral foot, or perineum. The calf, lateral, or plantar portion of the foot has sensory loss. There is a lack of strength in foot plantar flexion, hip extension, and knee flexion. Inability to tiptoe walk is caused by a lack of plantar flexion in the foot. It may also result in urine and fecal incontinence, as well as sexual dysfunction.

The crossing straight leg test, which is identical to the straight leg lift test but is performed on the asymptomatic limb, is another maneuver. When the patient reports pain in the symptomatic leg and the asymptomatic leg is at a 40-degree angle, the crossing straight leg test is deemed positive, indicating a central disc herniation with significant nerve root irritation.

 

How a Lumbar Herniated Disc is Diagnosed?

Without therapy, 85 to 90% of individuals with an acute herniated disc receive resolution of symptoms within 6 to 12 weeks. Patients who do not have radiculopathy get an improvement in even less time. The advise is to avoid ordering imaging scans during this period due to the high occurrence of disc herniation in routine neuroimaging of asymptomatic persons, since the research results will not change the care.

However, if there is a clinical suspicion of serious underlying disease or neurological deterioration, further assessment and imaging are required. Patients with red flag symptoms should have imaging and laboratory testing performed. Imaging is also advised in individuals who have not responded to conventional therapy after two to three months.

 

Laboratory tests: 

Erythrocyte sedimentation rate and C-reactive protein are inflammatory indicators that are required if the etiology is suspected to be a chronic inflammatory disorder or an infectious origin. A full blood count is beneficial when an illness or cancer is suspected.

 

X-rays:

Lumbar X-ray films are the first-line imaging diagnostic used in cases of low back discomfort. The typical examination involves three views (AP, lateral, and oblique) to assess overall spine alignment, diagnose fractures, and detect degenerative or spondylotic alterations. In order to measure spinal instability, lateral flexion and extension views are important. On X-ray, narrowed intervertebral space, traction osteophytes, and compensatory scoliosis are all signs of lumbar disc herniation. If an acute fracture is discovered, a computed tomographic (CT) scan or magnetic resonance imaging (MRI) is necessary.

 

CT:

This is the most sensitive imaging technique for examining the spine's bone components. CT imaging can be used to evaluate calcified herniated discs or any disease event that might cause bone loss or disintegration. It lacks the ability to see nerve roots, rendering it inappropriate for radiculopathy diagnosis. In patients who cannot get an MRI, CT myelography is the imaging modality of choice for detecting herniated discs.

 

How a Lumbar Herniated Disc is Managed?

Just because a disc has herniated does not automatically imply that surgery is required. A herniated disc is unlikely to necessitate surgery in the majority of instances. Treatment for a herniated disc is determined by the symptoms. It also depends on whether the symptoms are gradually worsening or gradually improving. If your symptoms worsen, your doctor may be more inclined to recommend surgery. Whether the symptoms are improving, he may advise watching and waiting to see if they go away. Many patients who have herniated disc difficulties discover that they totally recover within a few weeks or months.

 

Conservative Treatment

Nonsurgical Treatment of Lumbar Disc Herniation

• After the initial injury, the doctor may recommend cold therapy and medications.
• Cold treatment reduces edema, muscular spasms, and discomfort by lowering blood flow over the first 24 to 48 hours. Never apply cold or ice directly to your skin; instead, wrap the ice pack or cold product in a towel and place it on your skin for no more than 15 minutes.
• An anti-inflammatory medication to decrease swelling, a muscle relaxant to calm spasms, and a pain reliever to relieve extreme but temporary pain may be prescribed (acute pain).
• Nonsteroidal anti-inflammatory medications (NSAIDs) can be used to relieve mild to severe pain. These operate by reducing edema as well as discomfort.
• Heat treatment may usually be used after the first 48 hours. Heat causes an increase in blood flow, which warms and relaxes soft tissues. Increased blood flow aids in the removal of irritant substances that may build in tissues as a result of muscular spasms and intervertebral disc damage. Heat, like cold, should never be applied directly to the skin; instead, cover the heat source in a thick towel for no more than 20 minutes.

 

Spinal Injection

If the leg discomfort becomes severe or if limb weakness develops, the doctor may recommend an epidural steroid injection. An epidural steroid injection delivers anti-inflammatory medicine to the area of your lumbar spine near the afflicted nerves. Before beginning this therapy, you should discuss it with your doctor and inquire about any potential adverse effects.

 

Physical Therapy

Physical treatment may be recommended by the doctor. The physical therapist receives the doctor's directions through prescription. Physical therapy consists of a variety of therapies designed to reduce pain and promote flexibility. Some options include ice and heat therapy, mild massage, stretching, and pelvic traction, but your physical therapist will collaborate with you to build the optimal treatment plan for your pain and other symptoms.

The good news is: The majority of individuals discover that their symptoms are resolved without surgery within 4 to 6 weeks.

 

Surgical Treatment of a Lumbar Herniated Disc

If non-surgical therapy does not improve symptoms, spine surgery is explored. Continuous discomfort, limb weakness, or loss of function necessitates additional investigation. A lumbar herniated disc seldom causes bowel/bladder incontinence or groin/genital numbness, which need prompt medical care.

If surgery is advised, always inquire about the procedure's goal and the expected outcomes. You must comprehend all of the facts of what is being proposed, and you should not be afraid to seek a second opinion from another spine specialist. Spine surgery is a major choice that should not be taken lightly.

A discectomy is often performed to treat nerve irritation and leg discomfort (removal of all or part of the intervertebral disc). In addition, the surgeon may need to remove a part of the bone shielding the nerve to gain access to the herniated disc. A laminotomy is the medical term for this surgery.

Fortunately, these treatments are frequently performed using less invasive methods. Minimally invasive spine surgery does not require big incisions and instead employs small incisions as well as tiny specialized equipment and devices such as a microscope and endoscope throughout the procedure.

 

Can You Prevent a Lumbar Herniated Disc?

There are various elements under your control, and to take excellent care of your spine, check your posture, don't smoke, eat well, exercise, and utilize appropriate body mechanics, especially while lifting something. All of these things will not ensure that you will never have a lumbar herniated disc, but they are generally healthy actions you may take to attempt to avoid lower back discomfort caused by a herniated disc.

 

Complications of a Herniated Disc

A herniated disc might cause difficulties even before surgery. The development of cauda equina syndrome is the most dangerous consequence of a herniated disc. This occurs when a big chunk of disc material ruptures into the spinal canal, near where the nerves controlling the intestines and bladder pass before leaving the spine. Pressure on these nerves might result in irreversible injury. If this happens, you may lose control of your bowels and bladder. This is a major issue. Fortunately, it is also uncommon. If your doctor feels this is happening, he will quickly prescribe surgery to relieve the pressure on the nerves.

 

During Surgery

During surgery, several problems might develop. Any sort of surgery has the potential of complication owing to the anaesthetic utilized. Complications that may occur with herniated disc resection include:

     1. Nerve Injury

Working around the spine's nerves is required while removing a herniated disc. These nerves may be damaged during the procedure. If this happens, the nerve affected may be permanently damaged. This can result in persistent numbness, weakness, or discomfort in the part of the leg where the nerve goes.

     2. Dural Tear

The dura mater is a waterproof bag of tissue that surrounds the spinal cord and nerves. During surgery, a rip in this covering is possible. A dural tear is not uncommon with any sort of spine surgery. If this is discovered after surgery, it is simply corrected and normally heals without incident. If the rip is not identified, it may not heal. It is possible that it will continue to leak spinal fluid. This might lead to issues later on. A spinal headache can be caused by a spinal fluid leak. A leak can also raise the risk of spinal meningitis, an infection of the spinal fluid.

 

After Surgery

Some issues do not appear till after surgery; others appear shortly; and still others may take months to appear. These are some examples:

     1. Infection

Infection is a modest danger with any surgical operation, including spine surgery. Infection might develop in the skin incision, inside the disc, or around the spinal nerves. Antibiotics may be sufficient if the infection is localized to the skin incision. If the infection extends to the spinal canal or the disc area, a second surgery to drain it may be required. Following the second surgery, antibiotics will also be required.

     2. Re-herniation

There is always the possibility (approximately 10-15%) that the same disc will herniate again. It is most likely to happen within the first six weeks of surgery, although it can happen at any moment. If this happens, you may require a second procedure.

     3. Persistent Pain

Let's face it: these procedures don't always work. You may continue to feel pain for a variety of reasons. The strain from the disc herniation might actually harm the nerves, causing them to not fully heal. You may also develop scar tissue around the nerves weeks after the operation, causing agony comparable to what you were experiencing before the surgery. Your discomfort might also be caused by other issues in your back that have not been resolved by removing the herniated disc.

     4. Degenerative Disc Disease

Any lesion to a disc might cause degeneration of the affected spinal segment. A disc that has been operated on and a section of it removed has undoubtedly been damaged. Additional back issues in the region where a disc has been removed are not certain, but they are more likely. If the discomfort from the degenerative process gets severe, a second procedure may be required. Typically, this takes several years to develop.

 

Conclusion 

A herniated disk can develop anywhere along the spine, although it most commonly happens in the lower back. It is also known as a bulging, protruding, or ruptured disk. It is one of the most prevalent causes of lower back pain and leg discomfort, sometimes known as sciatica.