Lumbar Disc Herniation
Lower back problems can occur for many different reasons. The terms ruptured disc and slipped disc seem to be used more commonly in the last few decades. People often assume that everyone who has back pain has a ruptured disc. However, a true herniated nucleus pulposus (the official medical name for this problem) is not very common. Most problems that cause pain in the back are not due to a herniated disc.
The intervertebral discs are the cushions that act as shock absorbers between each of the vertebra in your spine. There is a disc between each vertebra. Each disc has a strong outer ring of fibers called the annulus, and a soft, jelly-like center called the nucleus pulposus.
The annulus is the disc’s outer layer and the strongest area of the disc. The annulus is actually a strong ligament that connects each vertebra together. The mushy nucleus of the disc serves as the main shock absorber.
A herniated disc occurs when the intervertebral disc’s outer fibers (the annulus) are damaged and the soft inner material of the nucleus pulposus ruptures out of its normal space. If the annulus tears near the spinal canal, the nucleus pulposus material can push into the spinal canal.
Usually a true herniated nucleus pulposus is most common in young and middle-aged adults. In older folks, the degenerative changes that occur in the spine with aging actually make it less likely for them to develop a true herniated disc.
Discs can rupture suddenly because of too much pressure all at once on a disc. For example, falling from a ladder and landing in a sitting position can cause a great amount of force across the spine. If the force is strong enough, either a vertebra can fracture or break, or a disc can rupture. Bendingover places a great amount of force on the discs between each vertebra. If you bend and try to lift something that is too heavy, the force can cause a disc to rupture.
Discs can also rupture from a small amount of force – usually due to weakening of the annulus fibers of the disc from repeated injuries that add up over time. As the annulus weakens, at some point you may lift something or bend in such a way that you cause too much pressure across the disc. The weakened disc ruptures while you are doing something that five years earlier would not have caused a problem. Such is the aging process of the spine.
A herniated disc causes problems in two ways.
First, the material that has ruptured into the spinal canal from the nucleus pulposus can cause pressure on the nerves in the spinal canal. There is also some evidence that the nucleus pulposus material causes a chemical irritation of the nerve roots. Both the pressure on the nerve root and the chemical irritation can lead to problems with how the nerve root works. The combination of the two can cause pain, weakness, and/or numbness in the area of the body that the nerve usually goes.
The symptoms of a true herniated disc may not include back pain at all! The symptoms of a herniated disc come from pressure on, and irritation of, the nerves. However, many people do have back pain because they have other problems in their back when the disc ruptures. The symptoms of a herniated disc usually include:
Pain that travels into one or both legs.
Numbness or tingling in areas of one or both legs.
Muscle weakness in certain muscles of one or both legs.
Loss of the reflexes in one or both legs.
Where these symptoms occur depends on which nerve(s) has been affected in the lumbar spine.
Therefore, the location of the symptoms helps determine your diagnosis. Knowing where the pain is perceived gives your doctor a better idea of which disc has probably ruptured.
Diagnosis of problem and a physical examination. The main questions your doctor will be interested in are:
Did you have an injury?
Where is the pain?
Do you have any numbness? Where?
Do you have any weakness? Where?
Have you had this problem or something like it before?
Have you had any weight loss, fevers, or illnesses recently?
Finally, your doctor will be interested in knowing if you have problems when you have to urinate or have a bowel movement. This is important to make sure there is no pressure from the herniated disc on the nerves that go to the bowels and bladder. If you do, this may be an emergency, and require immediate surgery.
Your doctor may suggest taking X-rays of your lower back. Regular X-rays will not show a herniated disc, but they will give your doctor an idea of how much wear and tear is present in the spine and may show other causes of your problem.
The most common test done today to diagnose a herniated disc is the MRI scan. This test is painless and very accurate. As far as we know, it does not have any side effects. It has almost completely replaced other tests, such as the myelogram and CAT scan, as the best test to do (after X-rays) if a herniated disc is suspected.
Just because a disc has herniated does not necessarily mean that you will need to undergo surgery. In the majority of cases, a herniated disc will probably not require surgery. Treatment of a herniated disc depends on the symptoms.
It also depends on whether the symptoms are getting steadily worse – or whether they are getting better. If the symptoms are getting steadily worse, your doctor may be more likely to suggest surgery. If the symptoms are getting better, he may suggest watching and waiting to see if the symptoms go away. Many people, who initially have problems due to a herniated disc, find that they completely resolve over several weeks or months.
Observation: You may not need any treatment other than watching to make sure that the problem does not progress. If the pain is bearable and there is no progression of weakness or numbness, your doctor may just suggest watching and waiting.
Rest: If the pain is more severe, you may need to take a few days off from work and decrease your activity for a while. After several days, you should begin to mobilize yourself. Begin a gentle walking program and increase the distance you walk each day.
Pain medications:Depending on the severity of your pain, different approaches can be used to help control your pain with medications.
Epidural Steroid Injection (ESI): The ESI is usually reserved for more severe pain due to a herniated disc.
It is not usually suggested unless surgery is fast becoming an option to try to reduce your pain.
Laminotomy and Discectomy
he traditional way of treating the herniated disc with surgery is to perform a laminotomy and discectomy. The term laminotomy means “make an opening in the lamina”, and the term discectomy means “remove the disc”.
Recently, improvements have been made in the tools available to the spinal surgeon for performing a laminotomy and discectomy. The procedure is essentially the same as the traditional way of removing a ruptured disc; however, it requires a much smaller incision. The advantage of this procedure over the traditional approach is that there is less damage to the normal parts of the spine during the operation. You may also recover faster.
After surgery, your doctor will probably suggest that you see a physical therapist before you start an exercise routine. Exercise is vital to recovery and to maintaining a healthy spine. Consider it part of long-term health management and risk reduction. Regular exercise is the most basic way to combat back problems. You need to make sure the exercises you choose are effective and safe for your particular case.
- Low back pain is a common complaint, with an estimated 70-85% of the adult population reported to experience this problem at some point during their lifetime.
- While the source of back pain – including pain radiating down from the back into the buttocks and lower extremities – can be difficult to diagnose, there are a number of signs and symptoms that indicate the presence of lumbar spine stenosis, literally, a narrowing of the spinal canal in the lower portion of the back.
- These symptoms are generally associated with a fatigue or discomfort felt in the buttocks, thighs, and legs bilaterally (on both sides of the body).
This fatigue is made worse by walking or standing and is often relieved by sitting to rest. Patients often complain of decreased ability to walk distances secondary to their fatigue or discomfort.
MRI (sagittal view) of normal spine
- Viewed from the side, the spine appears as alternating layers of vertebrae (bones that form a ring-like structure) and disks (soft spongy structures that provide cushioning between the vertebrae and contribute to mobility).
- Together, the vertebrae and disks form a column and a passageway through which the spinal cord (which houses a bundle of nerves) passes from the brain to the base of the spine.
- Viewed on a cross-section, one sees a more complex structure, which can be regarded as approximating that of a house.
Diagram of “House” analogy.
Most frequently, narrowing or stenosis within that structure may occur as the culmination of:
- a herniated disk, in which the foundation or basement of this “house” comes up to constrict the space .
- the development of arthritis, in which swelling occurs at the joints (usually where the “walls” of the “house” meet the “roof”), or
- as the result of the formation of bone spurs or osteophytes.
MRI (sagittal view) of lumbar spinal stenosis
- Trauma to the spine can also result in stenosis.
- In addition to the bony structures described above, there are soft tissues present in the spine, including ligaments and fat. Inflammation of these tissues can contribute to the problem.
Illustration of cross-section of spine.
In addition to a narrowing in the central canal of the spine, patients may have narrowing in the foramen, an opening (much like the window of the “house” that has been described) through which nerve roots extend on either side of the spine.
Finally, narrowing may occur in the lateral recess of the spine. Patients with stenosis may have any one or more affected areas.
Illustration of spine vertebra
Some people have congenital stenosis, a distinct condition from that which is discussed here.
- In these individuals, the “walls” of the “house” are abnormally short at birth and through development, thereby bringing pressure to bear on the spinal cord.
Pain and other symptoms of this condition are usually manifest by the time the individual reaches young adulthood.
The primary symptom of stenosis at any site is pain and fatigue resulting from pressure on the spinal cord or nerves.
People with stenosis of the central canal report pain that waxes and wanes, usually in the lower back, lower extremities, or the buttocks, that is worsened by walking or extension of the spine, and relieved when they sit to rest or when they lean forward.
While the actual site of stenosis is in the spine itself, pressure on the nerves is responsible for the referred pain in the buttocks or legs.
The pain from foraminal or lateral recess stenosis can mimic that of sciatica or disc herniations.
Unfortunately, stenosis is a degenerative and chronic disease. In more advanced cases, patients may develop cauda equina syndrome.
Named for the appearance of the nerve roots (which extend out at the base of the spine in a group of strands resembling a horses tail), this condition is characterized by urinary or bowel incontinence; saddle anesthesia, numbness or tingling at the inner parts of thighs near the genitals; and motor weakness.
To diagnose stenosis, the orthopedic surgeon takes a detailed history and conducts a physical examination and evaluates images obtained through either magnetic resonance imaging (MRI) or computed tomography (CT) with a myelogram.
In the latter procedure, a contrast material is injected into the affected area to show an outline of the nerve or nerves that are affected as well as the structures that are pressing on them.
The orthopaedic surgeon rules out the presence of vascular caudication, a condition that involves poor arterial circulation and shares some symptoms in common with stenosis of the lumbar spine.
He or she also does a thorough evaluation to determine whether other orthopedic conditions are present, such as osteoarthritis of the hip, that may be causing stenosis-like symptoms, or may also require treatment along with stenosis.
Treatment for lumbar spine stenosis begins with conservative measures which may include physical therapy to correct the forward-leaning posture many people with stenosis adopt in order to alleviate pressure on the nerves, use of anti-inflammatory medications, and the application of ice, heat, ultrasound or electrical stimulation to the affected area.
While the space within the spine cannot be expanded by these means, reducing inflammation, and thereby decreasing the pressure on the nerves, can offer pain relief.
Braces are not typically used to treat stenosis unless instability is present.
Older patients who are not surgical candidates may benefit from injections; however, advanced age alone is not a contraindication to surgery.
If these measures do not provide adequate relief, patients may be given a steroid (a potent anti-inflammatory agent) injection directly into the inflamed area to see if that relieves pressure.
Images obtained by MRI or CT myelogram guide the placement of these injections.
Response to this treatment is variable. Sometimes pain relief is significant and long lasting.
Other patients derive only transient pain relief, and may or may not respond to a repeat injection.
In order to minimize the side effects that can accompany treatment with steroids, no more than three injections be given in the course of a year.
Individuals who experience transient pain relief may be candidates for surgical intervention, since this response confirms that stenosis is at least part of the patient’s problem.
Surgery is only considered after other treatment options have been exhausted.
As with non-surgical treatment, the goal of surgical intervention is to remove the pressure on the nerves of the spinal cord and to restore mobility that has been lost owing to pain and fatigue.
Usually this is achieved by doing a decompressive laminectomy (removal of that portion of the vertebra that forms the “roof” of the house-like structure of the spine.)
In addition, the orthopaedic surgeon may remove any bone spurs that are present, as well as any soft tissue that is putting pressure on the spinal cord.
In doing so, the space through which the spinal cord passes is “opened up” and the pressure on the nerves is eliminated.
Although in some cases, the disease is focal, that is, affecting just one or two levels of the spine, sometimes it is more widespread, extending the entire length of the lumbar spine to the sacrum.
Depending on the extent of the area affected, patients may require fusion of the vertebrae in order to maintain stability of the spine after the laminectomy is performed.
Patients who undergo decompressive surgery usually remain in the hospital for a period of 3 to 5 days.
Physical therapy is initiated as soon as possible with an early focus on walking, followed by a program of strengthening and stabilizing for the muscles around the spine.
The patient must avoid any back bending, twisting, and lifting for about three months following surgery.
Overall, the success rate for surgical treatment of stenosis is about 85%, with varying degrees of improvement achieved among cases.
“Even if we can’t get the patient back to all the physical activities he or she once enjoyed, we can often get them back to performing activities of daily living, without discomfort.
In addition to offering pain relief, treatment of stenosis confers a psychological benefit as mobility is restored.
There are two common options in an outpatient lumbar discectomy—microdiscectomy and endoscopic (or percutaneous) discectomy.
A microdiscectomy is generally considered the gold standard for removing the herniated portion of a disc that is pressing on a nerve, as the procedure has a long history and many spine surgeons have extensive expertise in this approach.
While technically an open surgery, a microdiscectomy uses minimally invasive techniques and can be done with a relatively small incision and minimal tissue damage or disruption.
Indications for Microdiscectomy
If a patient’s leg pain due to a disc herniation is going to get better, it will generally do so within about six to twelve weeks of the onset of pain. As long as the pain is tolerable and the patient can function adequately, it is usually advisable to postpone surgery for a short period of time to see if the pain will resolve with non-surgical treatment alone.
If the leg pain is severe, however, it is also reasonable to consider surgery sooner. For example, if despite nonsurgical treatment the patient is experiencing pain so severe that it is difficult to sleep, go to work, or perform everyday activities, surgery may be considered before six weeks.
These are typical reasons for recommending a microdiscectomy:
- Leg pain has been experienced for at least six weeks
- An MRI scan or other test shows a herniated disc
- Leg pain (sciatica) is the patient’s main symptom, rather than simply lower back pain
- Nonsurgical treatments such as oral steroids, NSAIDs, and physical therapy have not brought sufficient pain relief.
The results of surgery are somewhat less favorable after three to six months have passed since the onset of symptoms, so doctors usually advise people not to postpone surgery for an extended period (beyond three to six months).
A microdiscectomy is generally considered a minimally invasive surgery, as there is minimal disruption of the tissues and structures in the lower back.
Traditional Microdiscectomy Surgery Step-By-Step
A microdiscectomy is performed through the back, so the patient lies face down on the operating table for the surgery. General anesthesia is used, and the procedure usually takes about one to two hours.
These steps are typical:
A microdiscectomy is performed through a 1 to 1½-inch incision in the midline of the low back.
First, the back muscles (erector spinae) are lifted off the bony arch (lamina) of the spine and moved to the side. Since these back muscles run vertically, they are held to the side with a retractor during the surgery; they do not need to be cut.
- The surgeon is then able to enter the spine by removing a membrane over the nerve roots (ligamentum flavum).
- Operating glasses (loupes) or an operating microscope allow the surgeon to clearly visualize the nerve root.
- In some cases, a small portion of the inside facet joint is removed both to facilitate access to the nerve root and to relieve any pressure or pinching on the nerve.
- The surgeon may make a small opening in the bony lamina (called a laminotomy) if needed to access the operative site.
- The nerve root is gently moved to the side.
- The surgeon uses small instruments to go under the nerve root and remove the fragments of disc material that have extruded out of the disc.
- The muscles are moved back into place.
- The surgical incision is closed and steri-strips are placed over the incision to help hold the skin in place to heal.
In a microdiscectomy, only the small portion of the disc that has herniated—or leaked out of the disc—is removed; the majority of the disc is left as is.
Importantly, since almost all the joints, ligaments and muscles are left intact, a microdiscectomy does not change the mechanical structure of the patient’s lower spine (lumbar spine).
After the Surgery
Patients typically stay in the surgery center or hospital for a few hours after surgery before being released to return home. Depending on the patient’s condition, one overnight stay in the hospital may be recommended.
Following the operation, patients may return to a relatively normal level of activities quickly. Patients are typically encouraged to walk within a few hours of the surgery.
The surgeon will provide home care instructions, typically including medications, activity restrictions, a follow-up care appointment, and other information.
A widely performed surgery, microdiscectomy is considered to have relatively high rates of success, especially in relieving patients’ leg pain (sciatica). Patients are usually able to return to a normal level of activity fairly quickly.
Microdiscectomy Success Rates
The success rate for microdiscectomy spine surgery is generally high, with one extensive medical study showing good or excellent results overall for 84% of people who have the procedure.
The medical literature also points to some benefits for surgery, when compared with nonsurgical treatment, though the difference lessens over time in certain cases. One large study found that people who had surgery for a lumbar herniated disc had greater improvement in symptoms for up to two years than those who did not have surgery.(Abraham P, Rennert RC, Martin JR, et al. The role of surgery for treatment of low back pain: insights from the randomized controlled Spine Patient Outcomes Research Trials. Surg Neurol Int. 2016;7:38.).
Recurrence of a Disc Herniation
Estimates vary, but between 1% and 20% of people who have a microdiscectomy will have another disc herniation at some point.
An additional disc herniation may occur directly after back surgery or many years later, although they are most common in the first three months after surgery. If the disc does herniate again, a revision microdiscectomy will generally be just as successful as the first operation. However, after a recurrence, the patient is at a higher risk of further recurrences.
For patients with multiple herniated disc recurrences, a spinal fusion may be recommended to prevent further recurrences. Removing the entire disc and fusing the level is the most common way to assure that no further herniated discs can occur.
Following microdiscectomy spine surgery, an exercise program of stretching, strengthening, and aerobic conditioning is recommended to help prevent recurrence of back pain or disc herniation.
Microdiscectomy Potential Risks and Complications
As with any form of spine surgery, there are several risks and complications associated with a microdiscectomy.
A dural tear (cerebrospinal fluid leak) occurs in about 1% to 7% of microdiscectomy surgeries. The leak does not change the results of surgery, but the patient may be asked to lie down for one to two days after surgery to allow the leak to seal.
- Your pain can come back.
- Your disc can re-herniate.
- Not all of your disc material may have been removed during your procedure.
- Your spinal cord, nerves, and blood vessels can be injured.
The good news is that many patients have significant pain relief from a microdiscectomy and can quickly return to their normal lives, generally in less than 2 weeks. However, your doctor will advise you on how quickly you can return to exercise and your other daily activities.
A successful microdiscectomy should accomplish what a traditional open discectomy accomplishes—but with a faster, less painful recovery.