What is lumbosacral instability?

Lumbosacral or lumbar segmental instability (LSI) is a name to describe a specific problem in the spine. It’s one of several subgroups of patients who have low back pain.

The actual problem is one of too much motion between two vertebrae. Mechanical overload is blamed for the loss of stiffness that occurs. Using the spine over and over with too much force can cause LSI.

Researchers have found one way to treat LSI is with spinal stabilization exercises. These exercises train the muscles to contract in ways that increase spinal stability.

When muscles on both sides of the vertebrae contract at the same time it’s called cocontraction. Exercises to promote patterns of cocontraction seem to help stabilize the spine and reduce pain for patients with LSI.

I’ve been having some back and leg pain the last few months. It almost seems like the leg pain is more disabling than the back pain. Is this typical?

The spine and hips do work together in many everyday activities. We know for sure that low back pain can decrease the ability to bend forward. Back pain with leg pain suggests abnormal tension on the sciatic nerve.

Anyone with leg pain of this type has increased tissue stiffness and decreased ability to stretch the hamstring muscle. This limitation will certainly affect other movements.

A recent study done at the University of Sydney in Australia confirmed all these findings. They used a 3-D, real-time motion device to study hip and spine movements. Results for subjects without back pain were compared to subjects with back pain and subjects with back and leg pain.

Just as you’ve noticed, the people with back and leg pain had a more difficult time. Movements such as standing up from sitting or sitting down from standing took longer. This suggests speed of motion is affected by back and leg pain. A lack of coordination of movements was also suspected.

Future studies hope to find ways to restore the normal muscle movement and coordination between the spine and hips.

I had spine surgery and woke up with a surprising new symptom: numbness along the front and sides of both thighs. The surgeon told me not to worry about it. She said it would be gone in less than a week and it was. What was it caused by?

You may have had a common post-operative condition called meralgia paresthetica. It’s caused by pressure on the lateral femoral cutaneous nerve (LFCN).

If you had surgery from the back you were likely face down during the operation. The surgeon may have used a special table or frame to support your body. Four posts support the chest and pelvis.

The hips are bent slightly and the abdomen is unsupported. It’s important to avoid pressure on the belly. Pressure on major blood vessels in the abdomen could cause bleeding.

However, in this position pressure on the LFCN can cause temporary impairment. Numbness or altered sensation can last anywhere from one week to two months. Once the pressure is removed the nerve recovers completely.

I’ve been having some back pain for the last three weeks. I can’t remember doing anything to bring it on. I notice in my Pilates class when I’m lying down I get a shooting pain down my left leg whenever I lift it up past a certain point. Is this what people refer to as sciatica?

People often use the term ‘sciatica’ to mean pain in the buttock and down the leg. The term actually refers to inflammation of the sciatic nerve. This nerve passes through the buttock and then travels down the leg.

Anything that irritates the sciatic nerve can cause pain and tenderness along the nerve pathway. The nerve can become entrapped by muscle or connective tissue. In some cases fibrous scar tissue inside the nerve sheath keeps the nerve from moving smoothly, thus causing pain.

Low back pain with leg pain may be more of an indication of pressure on the spinal nerve as it exits the spinal canal. When the leg is lifted off the floor, the back and/or leg pain occurs. This is called a positive straight leg raise.

A positive straight leg raise can be caused by anything pressing on the nerve. That could be a bulging disc, a bone spur, arthritic changes in the spine, or a tumor.

It might be a good idea to have your symptoms checked out. Early treatment can make a big difference for many conditions. Preventing chronic back pain is always important.

The MRIs of my spine and my symptoms tell the doctor I have a herniated disc with cauda equina syndrome. I’ve been advised to have surgery right away. Do you agree with this idea?

Cauda equina syndrome refers to the symptoms that occur when there’s pressure on the nerve roots below the level of the conus medullaris.

The spinal cord ends near the first lumbar vertebra. As it tapers to a point, it forms the conus medullaris. The bundle of nerve roots just below the conus medullaris is the cauda equina.

Cauda equina syndrome is caused by narrowing of the spinal canal. The result is pressure or compression on the nerve roots below the level where the spinal cord ends.

Cauda equina syndrome is usually a medical emergency. Surgical decompression is advised within 48 hours. The bone (lamina) is removed and then the disc is taken out to remove the pressure pushing against the spinal nerves. The goal is to reduce the chances of permanent neurologic injury.

I am trying to figure out what’s causing my pain. It’s either something in my low back or sacroiliac joint. The pain is on the right side right over the dimple in my low back area. Would an X-ray help show problems with my sacroiliac joint?

X-rays can show narrowing of the sacroiliac (SI) joint. This joint is subject to arthritis just like any other synovial joint. Narrowing of the joint space points to age-related degenerative changes.

The problem with these findings is that such changes can be seen in any patient over 30 years old. Such changes aren’t always linked to arthritis. Patients can have severe arthritic changes and have no pain. Others have no changes and severe pain.

X-rays can also show bone spurs, osteoporosis, or other changes in the bone itself. It can’t always show infection, inflammation, or instability. Doctors rely on other imaging and clinical tests to rule out more serious causes of SI pain.

I’ve been to four doctors for my low back pain that doesn’t go away. Nobody can find anything wrong. I’m not making up this pain, believe me. Why can’t they tell what’s wrong with me?

You’re not alone in your frustration about having back pain without a known cause. It makes sense to think that back pain comes from some abnormality in the spine or soft tissues around it. But in many cases no structural pathology can be found.

New studies are starting to show that back pain patients can be broken down into groups. The groups are based on age of the patients and type or location of pain.

One subgroup has been identified called lumbar segmental instability. In this group there is a loss of spinal stiffness. Too much motion occurs between the vertebrae. The patient may even describe a feeling or sensation of “instability catch.” This occurs when one vertebra slides too much against the vertebra above or below it.

Once researchers can put back pain patients in groups then proper treatment can be found.

I saw a chiropractor and a physical therapist for back pain this month. They both did this funky test pressing against my backbone several times. What does this tell them?

You may be describing a test for mobility or movement of the spinal segments. Were you lying face down on a mat or table? If so, then the test is called a posterior-anterior glide or mobility test.

The test is done using the pad of the palm on the little finger side. The examiner applies a gentle “spring-like” pressure down through the spinous process. The vertebrae at several levels are tested up and down the spine. This helps the examiner feel what’s normal for you.

The idea is to look for too much or too little motion. Treatment is based on whether the patient needs more or less motion at each level.

I just found out I have a collapsed disc at L45. What are my chances for a good result with surgery with a collapsed disc?

This may depend on how you define “good result” and what kind of surgery you’re planning.

A common operation for this type of problem is the anterior lumbar interbody fusion (ALIF). The remaining disc material is removed from between the two vertebrae. Two fusion cages are then inserted into the disc space.

The goal is to restore the normal disc space. You won’t have normal spinal motion at that segment because it will be fused. But reduced motion and restored space will result in pain relief in 80 to 86 percent of all cases.

In fact a recent study from the Virginia Spine Institute showed that patients with the worst collapsed discs had the best results when measured by pain relief.

My surgeon has explained what an anterior interbody fusion is but I’m not sure I really get it. Could you help put it into laymen’s terms?

In the simplest terms, an anterior lumbar interbody fusion (ALIF) is a spinal fusion. Two vertebral bones are fused together to stop motion at that segment.

Anterior means the operation is done from the front of the body. This helps prevent damage and scarring to the muscles, nerves, and blood vessels of the spine.

The disc material is removed from between the two lumbar vertebrae. Then a special device called a fusion cage is inserted into the space between the two vertebrae (interbody). As they are placed into the disc space, the space opens up even more.

The cages are usually threaded and made of titanium. There’s an open space inside the cage to put bone chips. This helps with the fusion process.

They may be tapered at one end to help keep a slight arch in the bone. This mimics the normal position of the disc and vertebral bones on either side.

My husband had a spinal fusion six months ago. Three of the lumbar spine were fused together. The X-ray report says there is a “nonunion” at L34. What does that mean exactly?

Nonunion means it didn’t fuse at one level. The X-ray probably showed a gap between the bones where the graft didn’t form solid, fused bone.

If dynamic X-rays are taken of the spine moving then motion would be seen at that level. With a successful fusion there should be no sign of movement between the two vertebral bones.

The spine may still be stable if the fusion is solid at the other two levels. Bone healing can take up to a year to complete. Your husband should make sure he goes to his follow-up visits. The final outcome may not be known until 12 months.

I went to a pain clinic for help with back and leg pain from a disc problem. The therapist says the goal is to “centralize the pain.” She explained the idea to me, but I didn’t get it. What does it mean again?

Centralization and peripheralization of pain are ideas from Robin McKenzie, a physical therapist who specializes in neck and back care. Pain from a disc pressing on the spinal nerve can cause back pain that goes into the buttock and down the leg.

By performing specific motions the pressure can be taken off the nerve. The pain “retreats” or moves away from the foot and leg and occurs just in the low back area.

Peripheralization of pain means the pain gets worse and goes from the back into the buttocks and down the leg. Or if there already was buttock and leg pain, it gets worse. The goal is to avoid peripheralization and to centralize the pain. This is a sign that the disc is moving in the right direction toward healing.

The therapist will help you find movements that centralize pain. These will become the exercises you’ll do throughout the day. She will also help you notice which movements peripheralize pain. You’ll want to avoid those positions and motions.

I am having low back pain that isn’t easy to diagnose. The doctor thinks it’s a disc problem but the MRI and CT scan were “normal.” The next test is a provocative discography. I’d really like to avoid more expensive tests. Is there anything else that might help?

There is a series of noninvasive tests called the McKenzie assessment that can be done by a physical therapist trained in this technique. There are eight basic movements the therapist will guide you through to find out what makes the pain better or worse. Making the pain better is called centralization.

A recent study showed that centralization of pain can predict when a discography would be positive. In other words, the McKenzie assessment can predict pain originating from a problem disc. The therapist can then give you a treatment program specifically for your type of disc pain.

This same study showed that the test results aren’t accurate with patients who are extremely distressed or severely disabled. Discography may be the only option for these patients. You can always try the McKenzie program and see if it works. If you don’t get better, your doctor may consider the discography as the next step.

My mother has had back pain off and on for 10 years or more. Her pain and disability is getting worse over time. Is this normal?

Some say “normal” is only a setting on your dryer. In the case of chronic back pain some people learn to manage their symptoms over time. Others become more and more distressed and disabled.

Scientists aren’t sure why this is so. Are there genetic factors? Do some people have a different “hard wiring” so-to-speak for pain? Are there certain psychosocial reasons why one person recovers while another gets worse? There’s no doubt that psychologic and emotional factors play a part.

Studies show that for the 10 percent of back pain patients who develop chronic pain, distress and disability is common.

I’ve had one disc operation so far for a herniated disc. I’m worried about this happening again. How often does this happen?

The best way to treat disc herniation to prevent recurrence still remains a mystery. Some studies show no difference after 10 years with or without surgery. Recurrence of this problem is reportedly as high as 50 percent.

This means that you have a 50-50 chance of disc herniation. Most likely, it will happen again at the same level and same side as the first herniation. Some doctors advise removing the entire disc to prevent this from occurring.

A new method of disc removal may help change this. It’s called microdiscectomy. A needle is guided by X-ray imaging into the disc space. The complete disc is removed. Sometimes, the vertebrae are fused together at that level to prevent motion. Studies to report the success of this operation are just beginning to be published.

My doctor has scheduled me for a microdiscectomy of the lumbar spine. How is this operation done?

The patient is asleep on the stomach. A small opening is made and a needle is guided into the disc space from the opposite side of the back. This approach avoids bleeding under the skin or into the muscles.

X-ray imaging called fluoroscopy is used to make sure the needle is in the right place. The doctor uses a microscope to move soft tissue and the nerve root out of the way. The disc material is removed, the needle is pulled out, and the back carefully closed up.

I had a spinal fusion at the L45 level. It didn’t heal and the X-ray shows no fusion. Why did this happen?

Failure of a fusion to heal occurs in as many as 35 percent of all patients. When movement occurs after a fusion, it’s called pseudoarthrosis or “false joint.”

There are many possible reasons why a solid spinal fusion doesn’t occur. Type of bone graft material used and number of previous operations are two factors. Others include whether screws, plates, or rods are used to hold the bone during healing and number of levels fused.

Patients who are smokers, overweight, or have diabetes are at greater risk for nonhealing bone. Some drugs, such as steroids or non-steroidal antiinflammatories delay healing.

Research to improve spinal bone fusion is ongoing. Improved surgery has already helped decrease the rate of pseudoarthrosis. Studies using electrical current to improve bone growth report some success.

I’m still having back pain after a lumbar fusion. The X-ray shows a solid fusion. What could be causing this?

No one knows the reason for this. There are some ideas, based on current research. Fusion does put increased pressure on the disc material between the vertebrae.

Over time, increased intradiscal pressure (IDP) may affect the life and health of the disc. The disc may start to break down, releasing chemicals that irritate the nearby spinal nerves.

It’s also possible that mechanical factors within the fused disc are the cause of continued pain in patients with a lumbar fusion. More studies are needed before we know the answer to this question.

My father just had a nerve block for sciatica. Isn’t this a risky treatment?

Nerve blocks are a common treatment for nerve pain caused by radiculopathy. Radiculopathy is defined as any disease involving a spinal nerve root. Sciatica is one form of radiculopathy.

Nerve injections do have some risks. The numbing agent can spread to other spinal levels giving false information. This can misdirect treatment.

More seriously, paralysis and death can occur if the steroid is injected into the blood vessels to the spinal cord. Some doctors have changed the way they do this procedure. Safer and more accurate methods of steroid injection are being studied.

As part of a return-to-work evaluation, I was recently tested for back strength. I was afraid of hurting myself again. I don’t think I gave my best effort. Will this affect the results?

This depends on the kind of test used to measure back strength. A special piece of equipment called a dynamometer can be used to measure ratios.

A range of test scores is used to account for fear, pain, or muscle stiffness during testing. This range is called the acceptance zone. Physical therapists who take these measurements know about these factors and take them into consideration during the evaluation.