DEGENERATIVE DISC "DISEASE"
"Degenerative Disc Disease" is a LOOSELY APPLIED TERM for changes seen on NEUROIMAGING STUDIES and MAY OR MAY NOT ACTUALLY BE A "DISEASE". MRI evidence has identified some Vertebral Body changes that suggest an "inflammatory" process in SOME PATIENTS.
For the majority of individuals, this is a normal process of "aging" (when used in relationship to the Disc and the various joints of the Spinal Column). While it is accurate to state that the process begins fairly early, the rate at which it progresses depends on a number of factors, some of which can be influenced by "life style" and habits. Others are less amenable to an individual's control.
signs of wear and tear develop in the individual vertebrae.
Imagine a moist bath sponge. If you press it hard then as soon as you let go it immediately returns to its former shape. It is elastic and flexible. Put a heavy stone on the sponge and let it dry in the sun, the sponge is a) pressed flat and stiff and b) no longer springs back into its original shape. It is hard, porous and its shape can no longer be changed. A similar thing happens to your intervertebral discs throughout life as with the sponge.
Damaged intervertebral discs are a phenomenon of wear and tear. The ageing process starts as soon as as a human being is able to walk. Even in 4 year olds age-related changes to the intervertebral discs can be detected.
What is meant by damage to intervertebral discs?
Damaged intervertebral discs are a phenomenon of wear and tear. As soon as a human being stands upright and walks, the intervertebral discs forfeit a little of their original perfection each day.
Intervertebral discs consist of a firm external outer layer known as the annulus fibrosus. This annulus fibrosus [fibrous ring] is filled with a jelly-like substance and a firm nucleus. Over time the discs constantly lose fluidity and forfeit elasticity and flexibility. So when put under pressure they are pressed together more forcefully – and are no longer able to return to their original shape. Overall the discs lose height.
The disc slowly dries out and the over time the fibrous ring develops fissures. These develop predominantly in the posterior part adjoining the spinal canal through which the nerve paths travel. Parts of the soft, jelly-like contents of the disc may escape into these fissures. The disc changes shape and bulges out towards the spinal canal. If the external layer tears completely and a hole develops in the fibrous ring, the jelly-like contents as well as the firm nucleus escape into the spinal canal – the classic prolapsed disc. Then nerves in the spinal canal threaten to become compressed. In this case patients complain about symptoms of paralysis. Then a doctor must be consulted immediately.
The most frequent consequence of damage to intervertebral discs is not a slipped disc but painful wear and tear (arthritis) on the surfaces of the vertebrae. Because of the defective 'shock absorbers' the vertebrae have to clearly take more pressure and are exposed to greater stress. In addition they can also become inflamed because of constant overloading.
Back pain from wear and tear.
In our youth the discs bulge with fluid and act as excellent buffers between the spinal vertebrae. They divert pressure and protect the vertebral bones from wear and tear. Because of the intervertebral discs the vertebrae sit stably on each other and are held together as if by chewing gum. At the same time the vertebrae can move easily without rubbing painfully against each other.
Over time discs lose fluidity and elasticity. So when put under pressure they are pressed together more forcefully – and are no longer able to return to their original shape. Overall the discs lose height and like everything that dries out a disc too can develop slight cracks and become damaged. Those affected then complain about severe back pain.
What factors lead to intervertebral disc degeneration?
Damaged intervertebral discs are a phenomenon of wear and tear. Like everything that is used on a daily basis, over time there are signs of overuse. In principle the signs of wear and tear begin as soon as a human being can stand on two legs and starts to walk. So even in 4-year old children the beginnings of age-related changes can be observed in the discs. Damage to intervertebral discs is a genetically pre-programmed condition and generally runs in the family.
Heavy lifting makes demands on the spinal column and accelerates wear and tear.
Being overweight, sedentary work and a lack of abdominal and back muscles can considerably hasten wear and tear. Likewise heavy strain or frequent poor postures. This is what we observe in our patients: For instance long-distance drivers or builders strain their backs particularly severely or nursery nurses in the Kindergarten frequently stoop and so have poor posture. Many also lift heavy objects incorrectly or carry weights that are too heavy, something which can trigger an acute prolapsed disc.
Pregnant women also have a greater risk of damaging their discs. During pregnancy the body's centre of gravity is displaced forwards. This puts more weight and pressure on the spine in the posterior region of the back. In addition the intervertebral discs store more water and lose stability because of hormonal changes.
Patients with congenital deformations of the spine or deformations caused by accidents also show accelerated signs of wear and tear. By constantly incorrectly putting weight on the spine the discs in affected people are more heavily loaded and also constantly deformed and put under immoderate strain.
Certain types of sport are also considered sports that can be dangerous to the back. Among others we include:
FACTORS INFLUENCING THIS PROCESS
Genetics or inherited factors (with the exception of certain very rare diseases) probably do not play any significant factor for the average patient. Humans, by virtue of their bipedal (walking on two lower extremities) nature, subject their Spines to forces on a daily, relentless basis that combine to accelerate a natural aging process. It is important to recognize that this affects all of the joints of the Spine as well as the Discs. The lower two Lumbar levels (Fourth and Fifth Lumbar, L4-5; Fifth Lumbar and First Sacral, L-5, S-1) assume a disproportionate weight-bearing burden by virtue of their location in the mechanism and function of the Spine. This "daily trauma" is, to a large extent, unavoidable. Other uncontrollable factors that further accelerate this process include congenital abnormalities of the Spine (defects in the bone and/or muscular parts of the Spine that we are born with) or developmental defects of these structures (those diseases which develop after birth — such as progressive abnormal curvatures called Scoliosis).
For each person there are many more factors affecting the "aging" or progressive "degenerative" process, that we can control, which are influenced by daily activities and life styles. Obesity and "over-weight" conditions add an unnecessary weight-bearing requirement. Heavy lifting and repetitive bending (particularly when standing up and leaning over at the waist to lift something) are two factors that are frequent contributors in all societies that require or encourage heavy work. Athletes or individuals who pursue certain sports activities add another dimension of accelerated Disc and Joint deterioration because of the added repetitive trauma to these structures. Whether it is in a weight lifter, jogger, football player, golfer or tennis enthusiast, each pursuit exacts some price with respect to the Spine and Discs.
None of this should be misconstrued by the reader as suggesting that these activities are either dangerous or undesirable. GOOD PHYSICAL CONDITIONING HELPS TO ASSURE GENERAL WELLNESS and is very desirable from the point of view of slowing the progressive degenerative processes that the Spine is inevitably subject to. IT IS merely a QUESTION OF DEGREE. We all must recognize that WE PAY A PRICE FOR THE THINGS WE DO. The Spine and its components are among those parts of the body where added "wear and tear" frequently results in an accelerated degenerative condition that ultimately may cause that part to fail to continue to function adequately.
The Primary Complaint of most patients is "Low Back Pain" without leg pain.
What are the symptoms of intervertebral disc damages?
Severe back pain and sometimes even feelings of numbness in arms or legs – these symptoms bring patients with intervertebral disc problems to us. What in colloquial language is described as „lumbago“ also describes the symptoms of an acute onset of pain resulting from intervertebral disc damage.
Lumbago is a sudden onset of pain as a result of a damaged intervertebral disc. Those affected complain about severe back pain.
If the pain emanates directly from the intervertebral disc it usually increases when standing or sitting – if more pressure is caused by a static load on the spine and therefore on the intervertebral discs. If those suffering from damaged intervertebral discs lean forward or rotate their upper body in a circular motion to relieve their back, this movement too can be very painful. Coughing and sneezing increase lower back pain.
If damaged discs press on the nerve paths running through the spinal canal, pain frequently radiates down the neck and arms or legs and feet. Sensations of numbness along with restricted function in the affected areas are also frequently observed with compressed nerves. Patients' arms and fingers are frequently getting numb.
If the pain also radiates from the vertebral joints then the affected person experiences a different kind of pain. In this case back pain increases when sitting or standing and especially when bending backwards. Sitting slightly bent forward on the other hand seems to give relief. Circular movements or a sideways tilt of the upper body are painful. If the spine of the affected person is tapped along its length, this also causes pain.
Patients with damaged intervertebral discs frequently show signs of painful and extremely tense back musculature because the spinal column is unstable. Tension in the neck region can radiate into the back of the head and produce symptoms of headaches. Sometimes damaged intervertebral discs in the cervical spine trigger headaches rather than backache. So it is not unusual for patients with severe headaches at the back of the head to have the cause diagnosed as damaged intervertebral discs.
The diagnosis is confirmed with the identification of some characteristic appearances best seen on Neuroimaging studies.
A. MRI Scan demonstrates the "dehydration" of the Disc and "decrease" of the Disc space height. The Lumbar Facet Joints demonstrate some degree of Hypertrophy (thickening) as does the underlying Ligamentum Flavum (Yellow Ligament).
Dr. Michael T. Modic described some MRI appearances that are considered characteristic of "Degenerative Disc Disease" (See Figure 2). These MRI changes are believed to reflect "fibrovascular replacement" of the normal bone marrow of the Vertebral Bodies. However, scientific publications have demonstrated similar appearances in various parts of Vertebral Bodies subjected to trauma and abnormal stress.
Professor Modic has stated in an EDITORIAL (published in the Journal of Neurosurgery: Spine Volume 6, pages 150-151, February 2007) that "the altered signal intensity detected by MR imaging is not, in and of itself, the causal process, but rather a reflection of the causal process that I believe is some type of biomechanical stress or instability."
He cautions that it is "premature given our current state of knowledge" to conclude "that the presence of Type 1 marrow changes in a patient with low-back symptoms is an indication that some type of stabilization or fusion procedure is needed."
B. CT Scan does not permit evaluation of the Disc Space other than to assess the intervertebral distance ("Disc Space collapse"). However, it provides better information about the Vertebral Bone and particularly of the Lumbar Facets.
DEGENERATIVE DISCS DO NOT, IN AND OF THEMSELVES, REQUIRE TREATMENT. WHILE THERE ARE METHODS TO DEMONSTRATE THAT THE DISC HAS BEEN "DAMAGED", THAT FACT ALONE DOES NOT JUSTIFY, IN OUR OPINION, ANY FORM OF SURGICAL MANIPULATION OR INTERVENTION.
A. Spinal Fusion
There are a number of ways to "Fuse" (permanently immobilize) one or more Disc Spaces.
B. "Artificial Disc"
That the Disc itself is subject to progressive degenerative changes, with or without the influence of the "accelerating" factors, is undeniable. Some joints in extremities can be successfully replaced (knees, hips, and finger) although there is a limit as to how long replacement joint materials will last.
"Artificial Disc Replacement" is being recommended by some of our more aggressive colleagues, as a primary surgical option for patients with Degenerative Disc "Disease" and/or Herniated Disc. THIS IS A HIGHLY CONTROVERSIAL AREA with proponents using SEVERAL DIFFERENT TYPES OF THESE ENTITIES WHICH ONLY RELATIVELY RECENTLY HAVE BEEN APPROVED BY THE FDA AS MECHANICAL DEVICES SUITABLE FOR HUMAN IMPLANTATION. THE CONCEPTS FOR THE UTILIZATION OF THESE DEVICES ARE STILL BEING EVALUATED.
Unfortunately this is one operation THAT CANNOT BE REVISED WITHOUT SIGNIFICANT RISK TO LIFE AND NEUROLOGICAL FUNCTION should complications ensue from the primary procedure. Currently there is no long term patient data on how long the synthetic materials or the various designs will hold up to the daily forces exerted on them with various postures. "Bench testing" in the form of machines made to duplicate human motion suggests that there is a reasonable longevity to these products. However, it is clear that in cases of replacement of other joints, such as knees or hips, there are real limitations to how long these artificial joints will last (frequently no more than 10 years.)
Surgical intervention in patients who suffer Neurological Symptoms from a herniated lumbar disc and/or surgically significant degenerative arthritis of adjacent joints become indicated in those patients where a serious trial of conservative treatment has failed; where neurological deficits are initially so severe that further delay will probably result in major permanent neurological deficit; where the neurological deficit is advancing (worsening) despite the conservative treatment or where nerve root compression, from narrowing (stenosis) of the spinal canal or nerve root exit area (neural foramen) is causing severe symptoms of Cauda Equina Claudication (see Lumbar Spine Information – Part 1.)
The presence of the symptom of Back Pain (by itself and not accompanied by any mechanical physical signs of nerve root compression, neurological involvement of the particular nerve root[s] or structural spinal instability) is rarely a valid indication for surgery. Recognizing that no reasonable person would wish to undergo an unnecessary operation, it is, therefore, important for patients with back pain to understand this concept if those who are not going to benefit from surgery are to avoid it.
The following information reflects our philosophy and collective experience, relating to the treatment of thousands of patients with these problems over the many years of our active involvement in Neurological Surgery.
Major advances in the field of NEUROIMAGING have improved the ability of neuro-radiologists and neuroimaging techniques to provide us with much more accurate information about the actual pathological situation affecting the spinal column, spinal canal and nerve root(s). CT (Computed Tomography) scan (also called CAT Scan-Computerized Axial Tomography) is one of these techniques. It should be recognized that this x-ray examination is subject to technical limitations and that not all CT scan machines or the people who run them or the radiologists who attempt to interpret the studies are as accurate as we would want them to be. In the event that a CT scan is supervised by a Neuroradiologist and interpreted by him (or her), then the chance for error has been reduced. The CT scan is "NON-INVASIVE" (no needles are used to penetrate the spinal canal). The effects of the expected aging process frequently produce changes that become evident on CT scan. A "degenerative disc," "disc space narrowing," "degenerative arthritis with bone spur formation," "narrowing of the spinal canal" (the medical term is "stenosis") and "bulging" (of one or more discs) are among the diagnostic impressions frequently reported by radiologists who review and interpret these studies. The patient must be prepared to realize that many, if not all, of these "conditions" are the result of the progressive changes of the aging process and may very well NOT respond to any form of surgery and SHOULD NOT be operated upon in the absence of an accompanying clear-cut neurological indication. (There are rare exceptions to this.) What the foregoing should mean to the informed patient is the following: "The mere presence, on the CT scan, of a bulging disc (or discs) coupled with other 'pathological' situations does not mean (in and of itself) that surgery should be done now or later."
MRI (Magnetic Resonance Imaging) has evolved as the single best Neuroimaging technique for the initial evaluation of the lumbar spine. It can be excellent for evaluating the spinal cord and some disc anatomy but does not give as detailed information about bone anatomy compared to CT. Often times when this information is placed in the context of a reliable neurological examination, the MRI derived information is sufficient for us to make an accurate assessment and to make a definitive surgical recommendation. In other words, the newer MRI technology has advanced to a point that it is frequently the sole source of "Neuroimaging" required for many patients. MRI scanning can also be of considerable help when evaluating certain post-operative conditions.
There appears to be a trend toward elucidating new "diseases" of the spine as more sophisticated and refined imaging methods become available, the result of which is that some of our very aggressive surgical colleagues have identified newer indications for surgical intervention. One of these "new diseases", for example, is called the "black disc". This appearance, seen on MRI (Magnetic Resonance Imaging) scans, is a normal phenomenon of diminished water content (dehydration) of the disc related to the natural process of aging and use. Depending on the extent of one's life-long physical activity (at work and/or with sports activities) and as we get older, our discs are subjected to more or less "wear and tear". This process results in some internal changes. The disc, which has a "rubbery" consistency under age 20, becomes less viscous, more dehydrated and more like "crab meat" as we age. The image of these changes appears on the MRI scan as "black". We wish to caution patients against assuming that something horrible is happening to their bodies or that this necessarily requires surgical treatment. We want to point out that this is, in most people, an entirely "natural" process of living and rarely is indicative of a "disease" process. In our opinion this is not a problem that should require surgical intervention in the absence of other more significant problems such as instability of the spine or neurological signs and symptoms.
For a number of reasons neither the CT nor the MRI scans may reveal enough of the structural situation of the spine for the surgeon to make a decision about the precise pathological anatomy upon which treatment alternatives and recommendations would be made. In this case the surgeon may request that a "MYELOGRAM" be done. This x-ray examination, conducted by a Neuroradiologist, involves the placement of a needle into the spinal canal. (The skin and underlying tissues are anesthetized with locally injected anesthetic agents.) A special dye substance is injected through the needle into a particular place in the spinal canal (subarachnoid space) where it mixes with the Cerebrospinal Fluid (CSF), and the pattern of the flow of the dye is watched on a special x-ray screen (called "fluoroscopy") similar to a television. In the event that a "mass lesion" is present in the spinal canal, Myelography can frequently outline its anatomical configuration. "Mass lesions" are any abnormal conditions in the spinal canal, which take up space and therefore, displace the nerve roots from their usual position. Herniated Disc, Bone Spurs, Synovial Cysts or Spinal Tumors (which are rare and most frequently completely benign) are examples of "mass lesions." Once again, this test is subject to some technical limitations, and the quality and accuracy of the study depends on these and the technicians as well as the radiologists performing and interpreting the study. Once the dye injection has been successfully accomplished and appropriate routine x-rays have been taken, the patient will be placed in the CT scanner. This phase of the study (known as "post-myelographic CT scan") is the most helpful imaging concept currently available. IT GIVES THE MOST PRECISE ANATOMICAL DETAIL OF THE BONE ANATOMY AND THE EFFECT OF STRUCTURAL PATHOLOGICAL CONDITIONS ON THE SPINAL CORD/NERVE ROOTS.
In the majority of patients who suffer from a herniated lumbar disc, Myelography is not required. Usually the CT or MRI scan gives sufficient information. Myelography is invasive; and although the risks of adverse reactions to the patient are very low, there are definite risks. An unnecessary myelogram is not in the patient's best interest.
There are some other forms of examination that are occasionally utilized. "Discography" and "Disco-CT Scan" (injecting a dye into the disc) is a painful procedure that has very limited indications and even more limited usefulness in helping to make clinical decisions. We strongly disapprove of this test and do not use it.
Diagnostic Nerve Blocks (injecting anesthetic agents near a nerve root or a facet joint) is being done with increasing frequency by some doctors. Unfortunately these procedures offer little to nothing diagnostically or therapeutically for patients with nerve root problems that are the result of herniated discs and/or spinal canal narrowing.
Electromyography (EMG) is an electrical test that is sufficiently reliable only in the hands of very capable Neurologists or Physical Medicine & Rehabilitation specialists. Tiny needles, inserted through the skin, measure very small electrical currents from nerves and the affected muscles. The test can provide some useful neurophysiologic information if properly done. The problem with the test is the wide variation of reproducible findings, which may render poor results making the examination unreliable. The degree of training and the extreme care, which the doctor brings to the test and utilizes in interpreting the results, are critical. This test is not necessary for most patients who are candidates for surgery. For others it may provide important information concerning fairly subtle neurological involvement.
Before undergoing any treatment, particularly an operation, it is reasonable to try to understand what will happen to patients if no treatment is undertaken.
Equally important is what will happen to patients who FAILED conservative treatment (patients suffering Lumbar Radiculopathy [injury to nerve roots] as a result of herniated or extruded discs with or without a component of spinal or foramenal stenosis or spinal stenosis and/or foramenal stenosis without the herniated disc) and a definitive operation is not done.
Several statements can be made about the "projected natural history." These are:
First, most Herniated Disc patients improve with a vigorous attempt at conservative therapy (initially with strict and complete bed rest) since the injury that resulted in a herniated disc is usually one where the Posterior Longitudinal Ligament and most of the Annulus Fibrosus remain intact (both are structures critical to holding a disc in place.)
Second, the degree to which patients subsequently remain free of symptoms depends on the extent of their initial injury (particularly to the capsule and ligament confining the disc) and the time that they allow, in the months following injury, for these structures to heal adequately.
Third, in the event that a nerve root is injured, the patient experiences pain and varying degrees of neurological deficit (such as tingling, numbness and muscle weakness).
Fourth, those patients who decide against surgery will continue to experience the pain for a fairly long time; however, the pain will eventually disappear once the nerve root dies. This could take weeks but more likely months to years.
Fifth, when the nerve dies the patient will be numb in the leg/and or foot region supplied by that nerve root. The muscles that receive their signals from the nerve will no longer work resulting in permanent paralysis. The degree to which this happens is variable in humans partly because of other nerve roots partially supplying similar regions and muscles. Nevertheless, it is unreasonable to expect, in these cases, to regrow a nerve supply to a paralyzed muscle.
Sixth, it is exceptionally rare for an "Extruded Disc" (one that has torn completely through the Annulus Fibrosus and the Posterior Longitudinal Ligament) to ever recede into its former "normal" position.
Seventh, when an extruded disc is not removed, more disc material could herniate through the already compromised Annulus Fibrosus and Posterior Longitudinal Ligament, placing more nerve roots at risk for serious injury.
The surgical procedures available for patients with herniated lumbar intervertebral discs and spinal and/or foramenal stenosis (narrowing of these spinal bone passages due to problems that are congenital and/or secondary to degenerative arthritis) have been utilized for many years. They are among the oldest operations ever performed on the nervous system. Modern trends have introduced some major advances. These are particularly related to the use of micro-neurosurgical techniques and specially designed instruments. In recent years we have introduced the more advanced techniques of Minimally Invasive Microendoscopic Surgery to spine surgery.
As a general rule patients who undergo these operations require a general anesthetic. Fortunately, modern anesthetic techniques have reduced the associated risk to life to a tiny fraction. The anesthesiologist will discuss the matters relating to the anesthetic and will be pleased to answer any questions that you may have.
There are certain basic surgical concepts to be understood before recognizing which particular procedure is chosen for a patient. Although degenerative changes affect more than one disc, it is unusual for more than one disc to require surgical attention at any particular time. Extruded discs (discs that have either broken through the confining capsule and ligament or have so damaged the ligament and disc capsule that they are no longer capable of holding disc material in place) are only rarely found to have come from more than one level. Removal of degenerative discs that have not frankly herniated as a "prevention measure" is not appropriate except in very isolated cases. The primary purpose of these operations is to relieve the pressure on the nerve root(s).
In the case of an extruded disc, the primary surgical purpose is to remove the fragment of disc that has escaped its confining capsule and ligament and relieve pressure upon the nerve root(s) and/or spinal cord. A secondary but equally important aim of surgery is to try to reduce the risks of recurrence of the problem. In most patients with an extruded disc, an attempt is made to remove as much remaining disc as possible from the disc space itself. This is in addition to removing the extruded fragment(s). In order for a herniation to have occurred, the confining capsule and ligament must have been severely damaged. Frequently there is a fairly large hole in these structures. Other fragments of disc could subsequently herniate from this disc space since the structures that help to prevent this (the capsule and ligament) have been damaged irreparably. Although it is not possible to remove every last fragment of disc from within the disc space, no matter how vigorous an attempt is made, the remaining disc is usually tenaciously bound to the bone of the vertebral body. While many surgeons restrict their operation for lumbar disc herniation to the removal of the herniated fragment(s), the reader should understand our rationale for removing as much disc material as possible in order to prevent the significant risk of recurrent herniation.
In many patients compression of the nerve root results from a combination of pathological conditions of which the herniated disc is one. Where bony spinal canal and neural foramen narrowing are also factors, it is important to remove the overlying bone which, then, allows for complete "decompression" of the involved nerve root(s). This is an essential part of the definitive operative management of these clinical problems.
Once the majority of the Intervertebral Disc has been removed scar tissue will eventually fill in the space from which the disc is excised. It is never as effective as the original disc was. However the scar can be sufficiently effective in subsequent "spine mechanics" provided proper healing occurs. In a similar way, the tear in the Posterior Longitudinal Ligament (which cannot be repaired surgically) will ultimately heal through scar formation. For both structures - the disc space and the Posterior Longitudinal Ligament - it will take three (3) months for the scar formation to be "firm" and six (6) months for it to become "solid". Allowing time for proper healing and limiting some activities in the early postoperative period are important factors contributing to the long-term success of these procedures.
The most frequent operations performed for these diseases involve an avenue of approach from the back (posterior). All of these techniques involve the removal of part or the entire "roof" (the "Lamina") of the spinal canal in the affected area. Removal of the lamina from both sides is a "LAMINECTOMY." Removal of the lamina from only one side is a "HEMILAMINECTOMY."
The most common operation involves removing only a thumbnail-size piece of bone from the lamina in order to gain access to the spinal canal where the herniated disc fragment is lying against the nerve root. This procedure is called a "LAMINOTOMY" (or opening in the lamina). The bony canal through which the nerve root travels as it leaves the spinal canal is called the "neural foramen". It is almost always desirable, and frequently necessary, to remove part of the roof of this foramen in order to decompress (relieve pressure on) the nerve root. This is called a "FORAMINOTOMY."
In the event that a bone spur is the culprit causing the nerve root compression, it may be possible to remove it. This is usually the case if the spur originates from the Facet Joint lying directly behind the nerve root. However, if the bone spur comes from the front of the spinal canal, it may not be possible to safely remove all or any of the spur. The decompression of the spinal canal and the affected neural foramen is most frequently very successful in treating the symptoms and signs of this problem. While it is quite evident that not all the bone spur is removed and that it could continue to enlarge, it is actually unlikely to cause any further major difficulties provided an adequate decompression has been accomplished.
Most patients undergo these operations to relieve the pressure being exerted on the Nerve Roots. They already have some Neurological Deficit(s). The older the patient is at the time of operation, the longer they have had the Neurological Deficit and the more severe it is, the less likely they are to recover. Whatever Neurological Deficit persists one year after operation, is likely to be permanent.
MINIMALLY INVASIVE MICROENDOSCOPIC SPINE SURGERY
There are now two technical options available with which to perform the surgery. The Minimally Invasive Microendoscopic Surgery approach involves a very short incision just off the midline to the side of the main problem. Rather than stripping muscle from the bone of the spine, as is done in the case of the more traditional (and very effective) Microsurgical Operation, this newer technique separates the muscle fibres using a specially designed small tubular retractor (called a "Port"). These "Paravertebral muscles", which run vertically on the side of the Spinous Process and Lamina, would customarily be removed from and then held in a retracted position from the bone of the spine in the more traditional Microsurgical approach. In both surgical methods a bone window is fashioned in the Lamina. It is through this opening that we gain access into the spinal canal. The nerve roots are protected by a "leather-like" covering (the dura mater). Once this is identified, the interior of the spinal canal is inspected. Frequently, the nerve root is tightly stretched over the extruded disc fragment(s) and/or bone spur. It must be protected and gently mobilized and perhaps moved a short distance in order to allow access to the mass inside the spinal canal. The extruded disc is then removed. In the event that the hole in the ligament and disc capsule (created as a result of the disc breaking through these confining structures) is not large enough to permit easy placement of instruments used to retrieve the remaining disc material from the disc space, then the hole is enlarged. After the remaining disc has been removed, the tissues are allowed to regain their former positions.
In the Minimally Invasive Microendoscopic Surgery the large back muscles, the fibres of which were spread apart by the special tubular retractor, fall back together. (In the more traditional technique these muscles would be scraped and separated from the bone and then must be re-approximated with strong suture material.) The skin incision is then closed in both types of surgery. In our cases, this is accomplished with "hidden" sutures.
Most patients who undergo these operations awaken from surgery essentially free of the severe pain that they had previously endured. Patients generally report that the pain from the incision in the back is not nearly as bothersome as that which they experienced preoperatively. The majority of patients are mobilized out of bed when they are awake and alert. It takes approximately three to four hours to completely recover from the effects of the anesthetic. It is important to get out of bed early unless you have been instructed otherwise. You will be asked to avoid taking excessive narcotic analgesic (pain reliever) in the early postoperative period in order to allow you to be mobilized. Narcotics make people sleepy which would preclude our staff from allowing you to be out of bed. The discomfort from the incision is rarely seriously painful. Actually once you are out of bed and walking, the pain is usually lessened even further.
Patients, who undergo a "laminectomy" procedure, should recognize that this more extensive operation (compared to a "laminotomy" for a herniated disc) may result in more discomfort, more analgesic medication and a longer stay in hospital. These will be discussed on an individual basis with the patient involved.
BILATERAL LAMINENECTOMY/UNILATERAL APPROACH
Bilateral Decompressive Laminectomy with Bilateral Foramenotomies using a unilateral (one-sided) approach is now possible, in many patients, using Minimally Invasive Microendoscopic Surgery. This highly advanced and technically demanding operation constitutes a major technical advance in the treatment of many patients with spinal stenosis as a component of their clinical problem. Minimally Invasive Microendoscopic procedures allow us to effectively remove and "decompress" BOTH sides (bilateral) of the spine using a ONE-SIDED (unilateral) APPROACH. This is a significant change compared with the more traditional operation which requires the stripping of paravertebral muscle from bone on both sides of the spinal column. In this Minimally Invasive UNILATERAL operation the paravertebral muscles are less affected resulting in significantly diminished post-operative pain. This technique is not always possible in all cases. Where it might apply, your surgeon will discuss it with you. (This advanced procedure is also utilized for the Minimally Invasive Microendoscopic management of certain spinal cord tumors.)
In patients suffering "Cauda Equina Claudication" (pain in the legs while walking) due to "Spinal Stenosis" (narrowing of the spinal canal-usually resulting from severe degenerative arthritis with or without "Spondylolisthesis" [see pages 13 & 14]) the option of Minimally Invasive Microendoscopic techniques offers a considerable advantage compared with standard Microsurgical operations. Multi-level decompression procedures are usually accomplished using a multiple "port" technique. In our practice experience we have used up to three (3) ports in order to effectively "decompress" Lumbar Spinal Stenosis at up to four (4) levels.
Additionally, we have recognized that the majority of patients undergoing a two (2) or three (3) level Minimally Invasive Bilateral Laminectomy using a Unilateral Approach, are able to and are desirous of leaving the hospital on the same day as surgery. This means that the operations are done through our "Day Surgery" facility.
INTERSPINOUS PROCESS DECOMPRESSIVE SYSTEM
Interspinous Process Decompression System is a relatively new Minimally Invasive procedure that is used to relieve symptoms of lumbar spinal stenosis, a narrowing of the passages for the spinal cord and nerves. There are several implantable devices, either made from titanium and/or other materials, that are designed to be placed between the "Spinous processes" (the thin projections from the back of the spinal bones to which muscle and ligaments are attached) of the symptomatic levels of the lower (lumbar) spine in order to limit extension of the spine in the affected area. X STOP® is one such device that has achieved FDA approval (others include the "DIAM device"; the "Coflex"; the "Wallis", the "Spire" etc.) The primary goal for this therapy is to relieve some or all of the symptoms of lumbar spinal stenosis and may improve a patient's ability to function. However, this does result in a larger, wider spinal canal as would occur with a "Laminectomy".
The implant is indicated for treatment of patients aged 50 or older suffering from pain or cramping in the legs (neurogenic intermittent claudication) secondary to a confirmed diagnosis of lumbar spinal stenosis. The use of this device is indicated for those patients with moderately impaired physical function who experience relief in flexion from their symptoms of leg/buttock/groin pain, with or without back pain, and have undergone a regimen of at least 6 months of nonoperative treatment. The devices may be implanted at one or two lumbar levels.
This new technology also has the potential for use as "fixation" or "stabilizing" procedure when combined with other Minimally Invasive techniques such as in older patients with a mild form (Grade 1) spondylolisthesis and spinal stenosis. In this case a Minimally Invasive Decompressive Laminectomy may be combined with the insertion of the Interspinous Decompression System in order to assist in maintaining "stability" of the spine. This device should not be used in patients with:
There are some additional "alternative" procedures to the operations described previously that are reviewed briefly for the reader's interest. This list is not a complete compilation of all the techniques available but it is reasonably comprehensive for most individuals who are learning about this subject.
In addition to the recognized risk of injury to the nerve root(s) due to the insertion of the needle, the enzyme can digest the disc material as well as nervous system tissue (nerve roots) if it is placed on the root(s). This complication results in a possible permanent paralysis of the lower extremities, bowel and bladder. Chemonucleolysis may be more expensive if hospitalization is longer and can only be used once in a patient's life because of the risk of death from an allergic reaction.
These last four procedures (Chemonucleolysis, Percutaneous Discectomy, IDET and Coblation) are incapable of managing a case with an extruded disc (one where the disc has actually escaped the confines of the encircling disc capsule and the Posterior Longitudinal Ligament) or those patients with bone spurs (osteophytes) that are compressing the nerve root(s) either from anteriorly or posteriorly.
While the indications for all four of these "alternative treatments" are similar, the long-term follow-up on a large number of patients does not reflect favorably on any of the procedures. In our opinion, most of the patients who are being chosen for these "alternatives" (by the procedures' advocates) would do better by receiving appropriate "conservative" or non-operative care. In those patients who have failed a serious trail of appropriate physical therapy, Minimally Invasive microsurgical techniques are more likely to offer a higher level of long-term relief.
"ANTERIOR LUMBAR INTERBODY FUSION"
"Anterior Lumbar Interbody Fusion" operations are done to remove the disc from the front (anterior) and then insert some form of device that ultimately will result in bone growing from one vertebral body to the next. This is commonly used for disc disease in the neck. However, it is a much more difficult operation through the abdomen. It is also associated with a significant risk of impotence in males. There are some very specific indications for this operation, but rarely do they include a herniated disc in the lumbar region, particularly if it is in a patient who has never been operated upon for a previously herniated disc.
"ARTIFICIAL DISC REPLACEMENT"
"Artificial Disc Replacement" is being recommended by some of our more aggressive colleagues, as a primary surgical option for patients with degenerative disc disease and/or herniated disc. This is a highly controversial area with protagonists using several different types of devices. Although the U.S. FDA (Federal Drug Administration) approved some of these mechanical devices for use in humans, the concepts are still in experimental stages. Unfortunately this is one operation that cannot be revised without significant risk to life and neurological function should complications ensue from the primary procedure. Currently there is no long term patient data on how long the synthetic materials or the various designs will hold up to the daily forces exerted on them with various postures. "Bench testing", in the form of machines made to duplicate human motion, suggests that there is a reasonable longevity to these products. However, it is clear that in cases of replacement of other joints, such as knees or hips, there are real limitations to how long these artificial joints will last (frequently no more than 10 years.) The utilization of such devices in the lumbar spine should be reserved for only those patients who have no other options. This is one area where a second or third opinion would be strongly advised.
One such device, the Charité disc, has been the subject of a large number of medical malpractice claims relating to their structural failure and the adverse consequences suffered by patients. The issue surrounding the variety of results seen after surgery coupled with the very limited scientific studies upon which the FDA approved this device, has caused some considerable concern. The disk was first approved in Europe, largely based on a highly limited study conducted there on 53 back pain patients. That study came to the conclusion that, "Proof that long-term results with the disk are at least as good as fusion results is still missing." This study offered the longest perspective of any to date, with a follow-up of 17 years.
A second European study of 107 back pain patients, with minimum follow-up of 10 years, concluded that the outcomes seen with the disc compared favorably with those typically seen with spinal fusion surgery. In the USA, the FDA based its approval on results from a study that found that back pain patients who received the disk did no worse than those who underwent spinal fusion. Follow-up in that study lasted for only 2 years.
We strongly urge anyone who has been advised to undergo this operation to do more research into the subject and obtain additional consultation.
Spinal manipulation, whether it is done by a chiropractor, osteopathic physician, orthopedic or neurological surgeon is absolutely contraindicated in the presence of an extruded disc or serious neurological injury to the nerve root(s) or where degenerative arthritis and bone spurs are factors producing the neurological deficit(s).
Spinal fusion, of any variety, is rarely ever indicated in patients who have never previously undergone operation for a herniated disc. The major indication, for any form of spinal fusion, should be instability of the spine. Fortunately this is not common among the majority of patients with herniated lumbar disc disease. In the event that there is the additional problem of instability in a particular patient, the surgeon will discuss the alternatives. The conditions discussed in subsequent paragraphs are among those where a "fusion" may be warranted, including our use of Minimally Invasive techniques.
Spinal fusion as a primary treatment for "back pain" and "degenerative arthritis" is commonly performed. This author strongly disapproves of this overuse of "fusion" procedures in the absence of demonstrated spinal "instability" and/or multiple recurrent herniated discs at that single level. We, again, urge anyone who has been advised to consider this operation to seek additional consultation.
In patients with the condition known as "Spondylolisthesis" (slippage of one vertebra upon another) the indication for a "fusion" procedure is usually quite clear. This clinical problem may be the result of a progressive degenerative change in the joints of the vertebrae (facet joints), a traumatic disruption of these joints or of a congenital structural defect. This term is almost exclusively reserved for spinal alignment problems of the lumbar spine resulting from a failure of "normal" bone structures to maintain the anatomical alignment of the spine. This means that one vertebra (or occasionally two vertebrae) "slips" forward (or backwards) relative to each other. The degree of slippage is referred to as either Stage 1 (minor slip of less than a 1/3 of the vertebral body distance); Stage 2 (slippage of a distance of 1/3 to 2/3 of a vertebral body) or Stage 3 (slippage of greater than 2/3 of the vertebral body distance.) There are some additional "slippage" problems which include dislocation of the vertebral body to one side (or "laterally" - called "Lateral Listhesis") which makes surgical correction even more complicated.
In patients with a "Congenital" form of Spondylolisthesis, the condition usually becomes apparent in the late teenage years to the 30's. The "congenital" problem responsible for this is a defect (failure to form) a small bridging vertebral bone element called the "pars interarticularis". This means that one or both facet joints of one of the vertebra have failed to connect to the remainder of its vertebra resulting in instability.
Most cases of Spondylolisthesis due to "Degenerative Arthritis" become apparent in the patient's life during or after the late 50's. In these cases the facet joints have suffered advanced deterioration and now are incapable of holding the patient's vertebrae in normal alignment. This Degenerative Arthritis (Osteoarthritis) "deterioration" is due to "trauma" occurring over the lifetime of that particular patient and usually results from a combination of factors such as obesity, activity in sports, weight lifting, heavy work activities, etc.
"Traumatic" Spondylolisthesis is the least common form of this entity. Fractures of one or both facet joints of a lumbar vertebra may result in this slippage.
These anatomical "misalignments" frequently cause compression of the neural elements (nerve roots either within the spinal canal and/or as they exit the spinal canal through the neural foramena.) This may injure those roots to produce a neurological injury (weakness and/or sensory impairment in the lower extremities) which is usually mild in the beginning. In unusually advanced case, patients may suffer impairment of bowel and/or bladder function in addition to weakness of the muscles of the legs and loss of sensory function in the lower extremities and perineum.
Pain and/or neurological deficit(s) frequently bring this condition to the patient's awareness. The degree of pain varies from one person to the next. Some, with advanced degrees of slippage (Stage 2), may not have had pain in previous years despite the fact that there was instability for many years when their condition was only a Stage 1 variety. Others have minor degrees of slippage and suffer considerable pain.
The fundamental concepts of the surgical treatment for Spondylolisthesis involves establishing and maintaining structural stability while relieving pressure on the affected nerves of the spinal column. In many cases we are able to re-establish the precise anatomical integrity of spinal vertebral alignment. For most cases with this condition, the surgeon can reduce the degree of slippage without restoring "perfect" alignment and still obtain a very satisfactory long term clinical result. The degree of the patient's original slippage and certain anatomical features peculiar to that patient may reduce the probability to achieve a complete anatomical reduction of the slippage.
In most of these cases some form of "fusion" operation is required. This usually means placing a device between the vertebral bodies that were previously in misalignment. The goal will be for bone to grow from one vertebral body to the adjacent one in order to maintain long-term stability. Additional structural stability is established with the incorporation of some other form of "fixation" device(s) such as pedicle screws and rods, interspinous fixation device and/or posterior (or postero-lateral) bone fusion. All of this is meant to demonstrate that there are several modern stabilization/fusion methods available. These alternatives will be discussed on an individual basis as indicated.
Of particular interest now is the introduction of Minimally Invasive Spinal Fusion techniques. This has some significant advantages with operations done through very small incisions since there is less "surgical trauma" to local tissues compared to more traditional (or "open") techniques. Patients undergoing Minimally Invasive Lumbar Spine Fusion are usually walking around the hospital ward within 4 hours of surgery and are generally discharged from hospital the morning following surgery.
All surgical procedures carry with them some element of risk. For lumbar laminectomy, foramenotomy, and discectomy, there are the general risks of any operation carried out under general anesthesia as well as risks specific for this operation. As a general rule, the degree of risk for any surgical misadventure or complication relating to these operations is very small. The risk to life is essentially that of the general anaesthetic. This actual risk is a tiny fraction on the order of 1/1000 of 1%.
The risk of injury to structures in the area of operation is present in any operation. Modern Micro-Neurosurgical and Minimally Invasive Microendoscopic techniques have helped to reduce these risks to very small fractions. The likelihood of paralysis of bowel and/or bladder function, paralysis of one or both lower extremities or impotence in males is remote. Likewise the risk to hemorrhage, infection, failure to relieve pain and/or the worsening or recurrence of the pain is small provided the patient adheres to the advice about postoperative care. It is possible that the neurological deficit, already present at the time of operation, will either worsen or fail to improve. In most cases it does improve quite quickly. As a general rule, whatever neurological deficit (sensory and/or motor function impairment) is still present one year after surgery, is probably permanent. The more advanced the neurological deficit is at the time of surgery, the longer it will take to improve and the less likely it is to completely recover. This does not mean that a patient with advanced neurological deficit cannot hope to improve; however, it is possible that some degree of neurological injury and disability will persist (sometimes it is only a small patch of numbness while in others a slight amount of weakness in the muscles that lift the top of the foot while walking.) Alternatively the numbness and weakness could be quite bothersome and limit many activities.
Although all operations are carried out with considerable caution, the sharp edge of bone or an instrument could inadvertently cut the Dura Mater (the tissue covering the nerve roots within the spinal canal.) This is an uncommon occurrence which, when recognized, usually only requires one small suture to close it. However, in the event where the small tear is not recognized or occurs at a later date, a postoperative leakage of cerebrospinal fluid (CSF) can occur requiring another operation to close the leak. The surgical incidence of this complication is reported to be 2%. Our experience is lower. It is important to understand that straining in the early post-operative weeks could also result in a tear of the dura mater (since straining could force the dura mater to bulge through the Decompressive bone opening in the spine which then tears as it rubs against the bone) and subsequent CSF leak One post-operative rule to follow is
One of the exceptionally rare complications reported in medical literature is an injury to the large blood vessels (and adjacent structures) in the abdominal cavity. This could occur if an instrument that is being used to remove disc material from the disk space is inadvertently pushed into the abdominal cavity. This would usually require an emergency repair of the hemorrhaging vessels within the abdominal cavity. Fortunately we have never personally experienced this serious problem.
Another potential serious complication is the postoperative occurrence of Arachnoiditis. The arachnoid is a thin filamentous membrane that lies inside the dura mater adjacent to the nerve roots. On rare occasion the arachnoid may react to injury (which may be from the trauma of the ruptured disc itself and/or Myelography as well as operation) by developing scar tissue inside the dura mater around the nerve roots. It is a very painful and potentially disabling condition. (Please see our "Arachnoiditis" Monograph, available in this website relating to our treatment experience with this difficult problem.)
For patients undergoing Lumbar Fusion Operations there are some additional risks such as the dislocation of the fusion device that was placed within the disc space. This unfortunate event could result in compression and injury to the nerve root(s) lying behind this dislocated device. This must be an uncommon experience and fortunately one which we have not ever had in any of our patients. It would, most likely, require another operation to correct the situation. Pedicle screws (that are used as part of some "fusion" operations) may injure nerve roots, become "loose" or require removal and replacement if suboptimally positioned. Rarely do the rods (that are placed as part of the "pedicle screw" implantation system) ever break. In the unlikely circumstance where this occurs, re-operation to remove or re-position the hardware may be required.
The postoperative care for individuals undergoing lumbar laminectomy/laminotomy and discectomy consists of very important steps towards as complete recovery as possible for the particular patient. Although most patients may go home on the same day of surgery, some remain overnight and are discharged from the hospital the following morning. There are circumstances, which may delay this. If you wish to take advantage of the "Same Day Discharge" opportunity, it is important to be sure that you are walking satisfactorily. After the first efforts at walking in the room, the nursing staff will assist you to walk in the hallways.
For those patients who undergo operation for the removal of a herniated intervertebral disc, it is important to LIMIT THE AMOUNT OF TIME for sitting (except for necessary bathroom functions) in the first couple of post-operative days. In the very early post-operative period, the preferred body positions are standing or lying down. When you leave the hospital it is preferred that you walk out. When being driven home (or to your hotel), try to do so in a reclining position (such as in the back seat of a large car or in a reclining passenger seat).
For those patients who undergo a Minimally Invasive "decompressive" laminectomy procedure (without removal of a herniated disc) and/or implantation of a Minimally Invasive Interspinous Decompression Device and those who undergo Minimally Invasive Lumbar Fusion procedures, you may begin sitting as soon as you find it comfortable to do so. In these situations we advise the patient to sit only in a straight-back chair, such as a kitchen or dining room chair. Please avoid recliners, sofas or "soft-back" chairs. Post-operatively you will, initially, want to sit for short periods of time and then increase it a little each day. For example, begin sitting for short meals. Then progressively increase the length of time that you sit and the frequency of sitting during the day. In unusual cases you will receive further instruction either at the time of discharge or at the time of your first office visit with the surgeon.
For patients undergoing a more extensive operation, such as a multiple-level laminectomy for decompression of a narrowed (stenotic) spinal canal, they must anticipate more postoperative discomfort and, perhaps, a longer postoperative hospital stay compared to those undergoing a more limited procedure for a single-level herniated disc. Nevertheless, early mobilization is just as important, if not more important. There are some other significant differences in postoperative care, including wound care that will be discussed with you as needed.
Please try to be aware of any activities or body positions, which produce pain since pain is your body's attempt to warn you of potentially harmful circumstances. Where you experience increasing pain, stop the activity and/or alter your body position. It is best to lie down for a while.
Walking will be your major form of exercise for several months. After the first day at home you may begin to walk out of doors (provided the weather is reasonable and there are no hills to negotiate). Set a reasonable schedule for pace and distance recognizing that as a general rule: "IF IT HURTS - DON'T DO IT!" A reasonable walking schedule should be developed and adhered to. Generally we find that most patients can walk at least one (1) mile per day at four (4) weeks postoperative and up to two (2) to four (4) miles per day after 6-8 weeks postoperative.
Avoid bending, stooping, lifting, pushing and pulling activities particularly in the first 2-3 postoperative months. Only lift that which can be easily accomplished with one arm. Do not lift anything with an outstretched arm. It takes time for tissues to heal. You can only cause delay in healing or interfere with the process with these activities.
Avoid aspirin and aspirin-containing compounds as well as ibuprofen containing drugs (Motrin, Medipren, Nuprin, Advil) since all of these interfere with the blood's clotting mechanism. Take as little pain medicine as possible. Tylenol (acetaminophen) or similar non-aspirin containing drugs should be all that are necessary. It is better to lie down when you have some pain than to take pain medicine to blunt the pain that is occurring from an activity that you are continuing to pursue. In the event that you need more potent analgesic medication, your physician will make the appropriate recommendations before you leave the hospital.
A general and well-balanced diet will provide the necessary nutrition to promote healing. We suggest that there be an added amount of protein intake to your diet during the post-operative months since protein is a primary source for the building blocks of repair of tissue.
You will have a list of other activities and personal hygiene given to you at the time of discharge from the hospital. Please make sure you understand what is expected and ask for clarifications. Your cooperation and strict adherence will help us to help you. It is very important to allow your body to heal itself to the maximum extent possible before stressing the operative site. Once you return to the office for follow-up visits you will receive further instructions as your recovery progresses and your condition warrants.
For those patients who come to us from other countries (or cities that are at some distance from Dallas), we will make special arrangements to contact you by telephone to discuss the progress of your care. In some instances, we will work with your local physician as required. In all cases, we will provide your local physician with the information that is relevant to your treatment. At a minimum, this will include the Operative Report and the Discharge Summary, both of which provide the technical details of the care that was provided to you.
Supplementary information, including diagrams, neuroimaging studies and examples of operations for these conditions can be found on our website as well as other venues.