FAQ Category: Lumbar Spine

Spine fusion is usually done as a last resort when conservative (nonoperative) care fails to reduce painful back and/or leg symptoms from degenerative disc disease or chronic disc herniations. Usually, the surgeon removes the disc and either puts a special device in that space (called an interbody spacer) or fills the hole with bone graft material.

Even with the interbody spacer, bone graft material is inserted in and around the area to help foster bone growth and subsequent fusion. Whenever bone graft is used, there are several different choices. There are two kinds of human bone graft: allograft (bone from a donor bank) or autograft (bone taken from the patient’s pelvis). A third choice is the use of rhBMP-2 bone substitute. rhBMP-2 stands for recombinant human bone morphogenetic protein type 2, so you can see why they shortened it to rhBMP-2. This protein stimulates the body’s natural production of bone.

As you said, there are pros and cons with each one. Bone graft from a bone bank doesn’t always take. Sometimes the body recognizes it as a foreign substance and sets up an immune response against it. But it does eliminate the need for an extra incision and harvesting of bone that is required with an autograft. Donor site pain, infection, and poor wound healing are often the biggest problems following a lumbar fusion with autograft.

Bone substitutes are not without their own issues. Studies have reported up to a 35 per cent complication rate using a bone substitute in lumbar fusions. Complications include screws coming loose or placed in the wrong position, interbody cage movement called migration, and infection. Sometimes pockets of blood form called hematomas or too much bone forms, a condition called heterotopic ossification. There can also be enough disturbance in the area of the spinal nerves that results in persistent nerve pain.

Leg pain from nerve irritation is called radiculitis. It is a common complication and one that is more likely when rhBMP-2 is used without a special agent called <Duraseal. Duraseal is a water tight sealant that keeps the bone substitute from leaking into the spinal canal or around the nerve roots where it could act as an irritant. Without the Duraseal, there is also a risk of bone formation in the spinal canal, which could put pressure on the spinal cord causing pain and dysfunction.

When it’s all said and done, both ways of accomplishing fusion are safe and effective but not without potential complications. Your surgeon may have some preferences in the choice based on experience and perhaps some individual factors in your case. Be sure and find out what his or her recommendations might be.

The transforaminal lumbar interbody fusion (TLIF) technique is used to avoid the problems that come with entering the spine from the front (anterior approach. Transforaminal means the surgeon gains access to the spine from the back and side. This allows the surgeon to avoid the major blood vessels present in the front (e.g., aorta, vena cava). The surgeon makes a posterolateral incision from the back and side and removes one of the facet (spinal) joints so the disc can be taken out.

Interbody describes how the fusion is circumferential (all the way around and from front-to-back). Once the disc is removed, the two vertebrae are distracted or pulled apart gently and a special device called an interbody spacer is slid into the disc space. The spacer helps restore normal disc height, which in turn, takes pressure off the spinal nerve roots as they leave the spinal cord and pass through the opening formed by the vertebral bones.

As you know, any time the area around the spinal cord and/or spinal nerves is disrupted, problems can occur. Irritation of the nerve tissue or pressure on the nerve tissue can set up an unrelenting pain response. Irritation or pressure can develop as a result of bleeding into the area, infection, or too much bone growth. The added bone is needed for the fusion but if it extends into the space for the spinal cord or spinal nerves, the same problems with persistent pain can develop.

Further surgery may be needed to remove anything from around the nerves. There’s no guarantee that the pain will go away. For some people, it does but for others, the pain signals aren’t as easily turned off once they get started. And scientists have yet to identify individual factors that might predict which way a person will respond.

The sciatic nerve is a large nerve that starts in the low back and goes down the back of the leg from hip to foot. As it travels through the buttocks area, it passes out of the pelvis through the a hole called the greater sciatic foramen. Pressure on the nerve in the lumbar spine area can cause pain called sciatica that travels from the buttock down the leg.

Nerve compression often comes from disc disease, especially disc protrusion. A disc herniation may also put pressure against a spinal nerve. True sciatic nerve pain from disc protrusion or herniation radiates down the leg past the knee, even going as far as the foot sometimes.

The basic flip test is done in the sitting position with the patient’s legs dangling off the edge of the table. The examiner holds under the patient’s heel and straightens the knee as far as it will go without putting so much tension on the nerve that it causes shooting pain down the leg. This position and movement place tension on the sciatic nerve. If it is compromised in any way, the test will be painful.

The flip test was first described 50 years ago as being positive when the patient fell backwards (flipped back) or had to brace him or herself to keep from falling backwards as the leg was straightened. A recent study of this test showed that various reactions can be interpreted as a positive flip test. For example, some patients may place their hands beside or behind the buttocks; others lean the trunk back 10 to 20 degrees. Some merely roll the pelvis back slightly. All of these reactions are in response to tension being placed on the sciatic nerve.

You have just described the supine straight leg raise test and the sitting straight leg raise test. Both put tension on the sciatic nerve and test to see if the nerve is being compressed or pinched as a cause of your pain. The sitting straight leg raise test is also known asthe flip test because some people back when tension on the nerve starts to cause pain.

Changing position by leaning back, bracing the hands on the table behind you, or tipping the pelvis under also takes pressure off the nerve. Although the original test was described as positive for sciatic nerve compression when the person flipped back, more recent tests show that the response may be more sublte as just described. In one study of patients with known disc herniation compressing the sciatic nerve, the sitting leg raise test was negative more often than positive.

As a result of that study, it’s been recommended that the sitting leg raise test should just be used to confirm the results of the supine straight leg raise.It’s only really valid when the supine straight leg raise test is positive in the first 45 degrees of leg lift. That’s when the sitting leg raise is the most reliable test to confirm the presence of sciatic nerve tension.

The fact that your sitting leg raise test was negative may have occurred because you shifted your trunk or pelvis to offset the tension. The examiner may not have seen that or recognized those compensatory movements as a positive response. If you had remained upright in the starting position throughout the test, the pain might have been reproduced (thus giving you a positive test).

You may be referring to the recent report from the Stanford Discography Project that showed some potential adverse effects of this test. It turns out that when the dye is injected into the disc, the tiny puncture wound damages the disc enough to cause future problems. Over time (seven to 10 years), the disc loses height and vitality. The risk of disc degeneration and herniation goes up. Maybe that won’t matter if you end up having that disc removed anyway. But often the discography is done on two or three vertebral levels trying to find the exact location of the problem.

It’s possible discography could be used effectively and safely with certain subgroups of patients but that hasn’t been investigated or discovered as yet. For now, it’s clear that the role of discography is being questioned and some further answers are needed. The Stanford Discography Project hopes to answer some of those questions in the not-too-distant future.

The fact that your surgeon is up-to-date on this information is a good sign. Previous studies questioning the use of discography have been ignored by too many people. This new evidence that discography has a potential role in future disc degeneration should be taken seriously. You may not be out of options yet. The next step is to meet with your surgeon and find out what are your diagnostic and treatment choices.

Discography is a provocative test that is done by injecting a dye into one or more discs suspected of causing painful back and/or leg symptoms. Damaged discs are chemically sensitive and react to the dye. The test reproduces the patient’s back pain right away — if the disc is causing the problem and if the right disc was injected.

There have been some questions raised about the validity and reliability of discography. And some recent research has shown a significant adverse effect of discography: disc degeneration and herniation after the procedure. But no one is quite ready to throw the baby out with the bathwater as the saying goes.

It’s one thing to say that a test doesn’t really show what you are looking for. No harm is done in that. It’s something else to show that the test has negative side effects. When the benefit of the test outweighs the risks, then patients and surgeons may agree to use it. But when the risks are far greater than the positive effects, then it’s time to rethink the process.

Many patients like you have already had the procedure — sometimes more than once. The involved disc was identified and removed. The painful symptoms are gone. You may have resumed your former or desired level of activity and all is well. Given the results of these studies, patients may be advised to stay in close communication with their surgeon to watch for future problems. But most of the patients in the study mentioned didn’t have any symptoms of disc problems, despite the MRI evidence that there was disc degeneration and herniation.

It’s too soon to jump to conclusions. Time and more study will reveal all.

It’s true that not everyone is comfortable in a pool of water — especially if it’s over your head and you are struggling to stay afloat. But in the right setting, it could be very reminiscent of being in the womb — calm and relaxing.

Warm water that supports your weight because of its buoyance takes a load off your joints — literally. At the same time, with aquatic therapy, it’s possible to work on improving balance, coordination, motion, and strength without fear of reinjury or increased symptoms afterwards. That’s because you control the amount of resistance by altering the speed with which you move and the height of the water.

Find a program that is conducted in a pool of water that is waist-to-chest deep. Avoid situations where you have to be in the deep end. If you are feeling panicked and can’t relax, aquatic therapy may not be for you. Remember to breath slowly and consistently. Holding the breath only increases a sense of panic and anxiety.

Let the instructor know of your concerns. A little extra support and enouragement from that individual can go a long way in helping you adjust. Give aquatic therapy a try — under the right circumstances, you may be pleasantly surprised at what you can accomplish!

Water-based exercise has many potential advantages over land-based exercise programs. The warmth and buoyancy combined with elimination of gravity eases joint pain and improves range-of-motion. And because the water gives resistance to movement, you can vary how much or how little resistance there is by standing in shallow versus deeper water and/or by moving slower or faster through the water.

But giving up core training for an aquatic program may not be the best approach. Both have specific advantages and accomplish different things. Core training is especially important for anyone with spinal instability. Strengthening the abdominal and trunk muscles helps provide support and stiffness for a spine that is too loose or lax.

You may be able to reproduce core training in the water but it’s best to have an expert help get you started. Physical therapists offer aquatic therapy for patients with all kinds of problems, not just low back pain. Another advantage of aquatic-based exercise is that it can give you the aerobic component that’s not possible on land if your spine isn’t strong enough or stable enough for that type of exercise.

Would it be possible to do a little cross-training? Perhaps you could alternate days and still get in 3 to 4 days of each type of exercise over a week’s time. In any case, don’t just stop doing one set of exercises and launch into a different type. Give your body a chance to respond and react to the new program. Monitor your symptoms. If they get worse, slowly reintroduce the core exercises you’ve been doing. If you get better, then perhaps you were on to something that works well for you!

Spinal stenosis refers to narrowing of the spinal canal or the intervertebral foramina of the lumbar spine. The spinal cord travels down the spinal canal, so anything that narrows that space can compress the cord. The spinal nerve roots exit the spinal cord through an opening in the vertebral bones called the intervertebral foramina.

There are many anatomical changes that can result in pressure or compression on the spinal cord or nerve roots. Most of these have to do with degenerative processes linked to aging. For example, osteophyte (bone spurs) can form around the facet (spinal) joints, thereby covering up the foramina (hole) where the nerve roots exit.

The discs narrow and may even bulge. Loss of disc height compresses the facet joints together. The joints rub together and start to hypertrophy (build up tissue around them to protect them). These changes can also narrow the foraminal openings where the spinal nerve roots leave the spinal cord.

At the same time, the major ligament down the back of the spinal cord (inside the spinal canal) called the ligamentum flavum starts to thicken. There’s just enough room in the normal, healthy spinal canal for the spinal cord and the ligament. A ligament that’s larger than normal adds to the pressure on the spinal cord.

The first place to start is with conservative (nonoperative) care. This is the most appropriate approach for patients with mild to moderate symptoms. Since the progression of stenosis is usually slow, there’s time to try conservative care. There’s no need to rush into surgery, especially for older adults who have other health concerns.

Pain relief and improved function in daily activities are the main goals of treatment. These are accomplished by activity modification and rest when necessary to keep symptoms from getting worse. Patients are advised NOT to stay in bed for long periods of time. Staying active without aggravating the symptoms is the way to go. The best way to do this is to avoid heavy lifting or movements that increase the symptoms (e.g., back extension).

Physical therapy can help patients recover faster with less long-term disability. The therapist will teach your wife how to do a series of flexion exercises. She will also be given a program for cardiovascular fitness and both flexibility and strengthening exercises. A total program of this type can increase the area inside the spinal canal and help improve blood supply to the spinal cord. Weight loss is an added benefit to any consistent exercise program. The therapist will also provide instructions regarding posture and conserving energy during daily activities.

If your wife’s symptoms persist after six to 12 weeks of conservative care, then surgery might be a possibility. There are some other alternative ways to treat this problem. Your physician will know how to advise you based on the results of tests, X-rays and other imaging studies, and response to nonoperative treatment.

According to the North American Spine Society (NASS), spinal stenosis describes a clinical syndrome of buttock or leg pain. These symptoms may occur with or without back pain. It is a condition in which the nerves in the spinal canal are closed in, or compressed.

The spinal canal is the hollow tube formed by the bones of the spinal column. Anything that causes this bony tube to shrink can squeeze the nerves inside. As a result of many years of wear and tear on the parts of the spine, the tissues nearest the spinal canal sometimes press against the nerves. This helps explain why lumbar spinal stenosis (stenosis of the low back) is a common cause of back problems in adults over 55 years old.

The diagnosis is made on the basis of the patient history, signs and symptoms, and clinical findings. The physician may perform some specific tests to pinpoint the problem but imaging studies are used to confirm the diagnosis.

Other tests may be ordered such as myelography, a type of radiographic examination that uses a contrast medium (dye) to detect pathology of the spinal cord. It helps show the extent of the stenosis. CT scans are better for seeing the surrounding bone and to look for bone spurs. Myelography and CT scans are also used for patients who can’t have an MRI because of a pacemaker or spinal stimulator.

These additional tests help in determining the best treatment for you. Surgery may be needed and the anatomical details that are provided by these tests will be important for the surgeon. Although conservative (nonoperative) care is always advocated first, if a person fails to respond to it, then surgery may be needed.

Sometimes imaging studies provide a baseline picture of what’s happening inside the spine. The physician can monitor the patient and use repeat images to tell if the condition is getting worse over time. That’s important because if surgery is going to help, it must be done within the first few years before the disease progresses too far.

Pain is a very complex event in the body. And chronic pain (pain that lasts past the usual time for healing) is an even more confounding mystery. Many, many scientists are studying ways to define it, describe it, diagnose the cause, and find ways to treat it fast and effectively. So far, there are no magic bullets.

It seems that besides the physiologic and biologic basis for pain, other factors enter in to the pain experience. Social factors, emotions, personality, and the psychologic make-up of the person all enter into the formula that results in pain.

As you may have experienced, managing pain often becomes a matter of trial-and-error looking for the right answer for each patient. What we really need is an evidence-based approach. One researcher has taken this idea a step in the right direction. Dr. J. Scholz, a neurologist and professor of anesthesia at Harvard Medical School has developed a test to diagnose neuropathic (nerve-related) pain from non-neuropathic pain.

The test is called the Standardized Evaluation of Pain or StEP. It is a highly sensitive and specific test for telling the difference between neuropathic and non-neuropathic pain. patients are asked a series of six interview questions and given 10 simple physical tests. From this tool, it is possible to accurately assess patients’ pain.

That’s helpful because treatment can be directed more specifically if the underlying cause can be determined. The target of therapy should not just be masking pain but should go right to the active mechanism causing the pain and put a stop to it.

But to answer your question, we are far from being able to do one simple test and know for certain what’s causing a person’s pain and how to deal with it most effectively. This new tool is a step in the right direction. It will ultimately help pain experts predict what patient responses will be to specific treatments. Choosing a treatment right from the start that has a high chance of success is the ultimate goal in pain management.

Some new and important discoveries are being made about low back pain. For example, it used to be said over and over that eight out of 10 people would suffer a bout of back pain at least once in their lifetime. That’s still true. But the next part of the story may not be so true.

Based on the best evidence available, doctors have been advised to tell their patients that with a short period of rest followed by as much activity as tolerated, the pain would go away in one to two weeks. That’s still true, too — but not for everyone. In fact, some recent studies have reported that three out of every four back pain patients still have back pain three to 12 months later.

A closer look helps explain some of these statistics. Advanced imaging and neurophysiologic and precision diagnostic techniques have shown scientists that spine pain can come from more than one place. Pain could be from the muscles, ligaments, discs, joints, or a combination of two or more of those places.

If your injury damaged more than one area of the spine and possibly even several different types of soft tissues, recovery may be much slower and require more time and attention than a simple muscle strain. Since each one of these areas requires a slightly different approach, one treatment method may not be effective. In fact, that probably explains why there are so many different ways to treat chronic low back pain. Some are nonoperative while others involve complex and challenging surgeries.

If you have not been back for a medical evaluation since your original injury, it would be a good idea to have some additional testing done to find out what’s going on. The more closely your problem can be identified, the better the chances are for a successful recovery. Treatment must be matched as closely as possible to the underlying anatomical and biomechanical problems.

There are a few things to consider in a case like this. The first is whether or not your back pain is mechanical rather than the result of a serious health problem such as cancer or heart disease. If your physician has cleared you to return to work when you feel ready, then perhaps it is time to ease back into the job.

And that’s the second consideration. Do you feel ready to just jump back to your previous level of work? Can you handle the work load? A recent study from the Netherlands showed that older adults do well getting back on-the-job if there is a series of steps to modify or grade the required activities. It’s likely that folks in this age category (over 44 years old for that particular study) had a good idea of what it takes to get better and they were willing to do it.

Surprisingly, it wasn’t the level of pain, gender (male versus female), or the workload (heavy manual labor) that made a difference in whether or not the employee could successfully return to work sooner than later.

If your physician approves the return-to-work status and you feel ready, the next step is to talk with your employer about any special arrangements you may need (if any). Good luck!

It is entirely possible that you might experience nonspecific low back pain at some point in your life. It’s estimated that eight out of every 10 adults will report this problem to their physicians. But the prognosis is good. If there’s no fracture, tumor, infection, or other serious problem, most people are back up and on their feet quickly.

But a small number of people do go on to develop chronic pain and disability. They may be off work for several weeks or more. Research is focused on finding ways to prevent back pain. One way to do this is to study groups of people who have low back pain and see if there are any common features to help predict those who might be at risk.

A second approach is to identify subgroups of patients who seem to respond well to a particular type of treatment. Studies have already shown that age, gender, and poor function are predictive of longer use of sick leave. On the flip side, another study has shown that previous use of sick leave is a positive factor in response to work modification as a means of returning to work sooner.

There’s no reason not to be prepared for various health issues and concers. But you are probably right that preparing for something just because it has happened to other people may not be necessary.

There’s no doubt that smaller incisions during spine surgery (called minimally invasive spine surgery or MISS) has many advantages. Besides the tiny scar left behind, patients experience less tissue trauma. There is faster recovery of muscle strength when muscles don’t have to be cut away and reattached at the end of the operation.

Some studies show less blood loss with MISS, shorter hospital stays, and lower costs as a result. With fluoroscopy for viewing the spine, accuracy is improved when placing tiny screws in the vertebrae through these small incisions.

Why isn’t it done more often? There are several reasons. Not every hospital can afford to invest in the surgical tools necessary for this type of procedure. With each specialty area, new technology is available but very expensive. There are laser tools for cancer surgeries, computer-based CT and MRI scans, fluoroscopes (real-time X-rays) for orthopedic surgeries, and so on. From a business point-of-view, they purchase the equipment that will be used the most.

Surgeons must take the time to get trained in these newer techniques. Of course, each surgeon will have his or her own transition time learning how to do surgery with minimally invasive methods. Patient safety and good results are always on the surgeon’s mind.

It does take time and practice to learn any new skill or surgical technique. If there isn’t a large number of people in the area who will need the particular minimally invasive surgery needed, then the surgeon is less likely to seek out that training.

There’s been a lot of talk about stem cell research. Many scientists are convinced that the results of aging-related degeneration of the spine can be altered with stem cells. For example, the breakdown of disc material between the vertebral bones could be repaired by regenerating discs with stem cells.

But until that’s really available, other researchers continue to study alternative methods to replace the intervertebral discs. As you know, artificial disc replacement is now available. And just as you suspected, efforts are also underway to just replace the center portion of the disc called the nucleus pulposus.

Advanced technology now allows the surgeon to remove the damaged or degenerated nucleus pulposus and insert an implant in its place. The implant (prosthesis) is designed to bear the load through the spine at that level and prevent further collapse of the affected vertebral segments. The hope is that the remaining disc will be protected and remain strong over time.

Nucleus pulposus biotechnology has already gone through several generations of pulposus replacements. Replacement materials for the nucleus come in two basic types. There are mechanical metal or carbon devices that are inserted into the space left by removal of the pulposus. And there are injectable elastomers that fill up the nucleus pulposus cavity and harden after they have been squirted into place.

Studies so far have been encouraging. A large proportion of the small number of patients studied experienced pain reduction, decreased use of narcotic drugs for pain, and improved function. Complication rates have been low. And the discs have been shown to withstand 10 million cycles of fatigue when tested biomechanically using cadavers (vertebral segments preserved for study after death).

Most of the studies done so far have been completed by the companies that designed and developed the implants. Before these can be adopted for regular use, tests must advance from cadavers to animals to clinical trials with humans — first by the disc replacement industry and then by outside, independent agents. The race is on to find a way to slow or reverse disc degeneration eliminating the need for nucleus (partial) or disc (complete) replacement.

Advanced technology now allows the surgeon to remove the damaged or degenerated nucleus pulposus and insert an implant in its place. Usually the entire disc is removed and replaced. But efforts to replace just the central nucleus of the disc are being investigated.

They are having some success but there are two commonly encountered complications: extrusion and subsidence. Extrusion can occur when a liquid gel is used to create the new nucleus. Once injected, the materials can shoot past or ooze out of the inner space for the nucleus.

The tiny hole made in order to inject the material into the disc center leaves an opening for a quick exit of the same material. The hole must be closed to keep extrusion from happening. Finding the right material to make the patch, seal the hole, or develop an effective suture to close the open edges is part of today’s research efforts.

The second potential problem mentioned (subsidence) refers to the fact that the new nucleus sinks down into the annulus (outer fibrous covering around the nucleus). Then the whole disc can sink into the endplates. Endplates are fibrous cartilage located between the disc and the vertebral bones. Researchers are tinkering with the shape and size of the implant to help stop this problem. By measuring the stress or load placed on the endplates, they have been able to see higher stress at the center of the endplate. This information has guided them in reshaping the implant.

Right now scientists are still working with various liquids that flow smoothly and then self-cure (harden after injection) into one piece. This process is called polymerization. The process requires careful temperature control to move the liquid at body temperature and shift from a liquid to a gel without clumping or swelling while still conforming to the shape and size of each patient’s disc space.

Different materials are being tested. For example, silk and elastin proteins are being tested as an implantable liquid that cross-links with collagen within 90 seconds of injection. The advantage of that feature is that it restores the disc strength and biomechanics right away. The next test will be to see if it can hold up under the many, many fatigue cycles placed on it by the average adult.

In other laboratories, a different approach is being investigated. Preshrunk forms are inserted into the disc center and rehydrated as the implant sucks up nearby fluid, swelling to fill the cavity. The fully hydrated implant transfers load from the disc to the vertebral endplates.

With each new type of material developed, there are individual problems that crop up. It’s possible that by the time a material is ready for market, stem cell research or gene therapy will have advanced enough to prevent disc problems from happening in the first place. Tissue reengineering may ultimately replace disc replacement technology.

The X-stop is an interspinous spacer which means it is placed between two spinous processes and holds them apart. Those are the bumps you feel along your back. They are knobs of bone that extend out from the vertebral bodies.

By using a device like this, spinal motion into extension (bending backward) is limited. Without extension, there’s less chance of pressure on the spinal cord. For conditions like spinal stenosis (narrowing of the spinal canal), the X-stop seems like a good idea.

The X-stop can be inserted under local anesthesia. The ligaments around the spine are saved from being cut. The device slips right through a slit made in the ligament. So, everyone agrees the X-stop is easy to use. But does it work? That’s the question!

Right now, there isn’t enough evidence from high-quality designs to answer that question. Early, short-term results show a positive benefit (pain reduction, improved function) in more than three-fourths of the patients. Safety is always a concern but complications such as infection, fracture, increased pain, or implant movement or breakage have been very low so far.

There’s no data on larger groups of patients or on the long-term results. Recently, two neurosurgeons from New York reviewed the latest findings on these devices. They commented on the poor quality of some of the research that has been done. They say that the study design was questionable for many of the studies. The authors strongly urge random controlled trials to find out when these devices should be used and with whom.

Your best bet is to make an appointment for your mother with her doctor to investigate possible treatment choices for her condition. There are effective treatments for people with spinal stenosis. She should be able to get some relief from the pain at least and maybe even some improved motion.

There is an interspinous spacer on the market for the treatment of back pain from spinal stenosis that may eventually be approved for use with scoliosis (curvature of the spine). Interspinous means the spacers are placed between two spinous processes. Those are the bumps you feel along your back. They are knobs of bone that extend out from the vertebral bodies.

Spinal stenosis is a narrowing of the spinal canal, the opening formed by the vertebral arches. This is where the spinal cord travels from the brain to the base of the spine. Lumbar spinal stenosis is a common problem in older adults (age over 65). Low back pain and/or leg pain/discomfort are the first signs of this problem.

Placing this device between the spinous processes keeps the spine from bending backwards. Right now, only one spacer has been approved by the Food and Drug Administration. That’s the X-Stop. Its primary use is with spinal stenosis. Three others are being studied with the intent to seek FDA approval.

They are the Interspinous U (also called Coflex, the DIAM, and the Wallis system. The Interspinous U may have more uses than just spinal stenosis. The manufacturer says that it holds the spine stable in both flexion and extension and may be helpful with scoliosis. Right now, it has only been approved for investigational studies in humans.

It may be a while before effective products are ready to help stabilize scoliosis in adults without the major surgery needed to insert rods alongside the spine. But check with your surgeon and let him or her know of your interest. There may be something else that could help you in the interim.

There are many different ways to treat low back pain. When surgery is needed, there are different options as well. Spinal fusion may be necessary in the case of degenerative disc disease, tumor, infection, deformity, or spinal instability. Just like everything else, fusions can be done in different ways with different approaches.

Interbody fusion is a common method of performing spinal fusion. Interbody refers to the fact that after removing the disc, the surgeon inserts a metal cage, spacer, or bone graft material in the empty space between the two vertebrae. Bone graft material is packed in and around the area to help the fusion process along.

Even with interbody fusion, there are different ways to approach the spine. The surgeon may come in from the front of the body. This is called the anterior approach. Surgery from the back of the spine is a posterior approach. Sometimes a posterolateral approach is used — angled between the back and the side. No matter which method is used, the goal is always the same: to restore the disc height and vertebral segment spacing and restore spine stability as close to normal as possible.

Each approach has its advantages and disadvantages. There is even a new way of doing this surgery called extreme lateral interbody fusion (XLIF). It sounds like this might have been the type of surgery you viewed in the office. The surgeon goes through the side with only disruption of the psoas (hip) muscle. There are no major organs to avoid (as with the anterior approach). There’s no need to strip away large groups of muscles or cut through nerves (as with the posterior or posterolateral approach).

Special X-ray techniques such as fluoroscopy and real-time electromyography (EMG) are used to guide the surgeon and monitor the patient. Using these tools, the surgeon can move safely through the body to the spine avoiding the abdominal contents and without damaging vital nerves, blood vessels, and soft tissues.

The most difficult part of the operation is to move through the psoas muscle without disrupting the lumbar nerve plexus. That’s where EMG comes in handy. The tool used for the XLIF has a tiny EMG electrode on the tip giving the surgeon continuous feedback on the location of the psoas muscle. The fluoroscope is used once again after the disc material has been removed to put the spacer in place and to pack it with bone graft material.

XLIF was developed in response to some of the problems that occur with other types of fusion procedures. The XLIF is less invasive with a smaller incision, less disruption and damage to the soft tissues, decreased blood loss, and provides a faster recovery.

With the ability to gain access to the disc space without stripping away the muscles, there is a hope that future problems with adjacent segment degeneration can be prevented. Adjacent segment degeneration refers to the breakdown of the next vertebral segment as a result of a transfer of load from the fused site to the next mobile segment.

Studies done so far with the XLIF report good results. There’s been no question about the safety and effectiveness of XLIF for interbody fusion. They have even used it with multilevel fusions in patients with other problems like scoliosis. But the studies are limited and with only a few patients. Larger, randomized controlled trials comparing XLIF to other fusion operations are still needed before this approach will be widely adopted.