FAQ Category: Lumbar Spine

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.

Surgeons have tried to improve spinal fusion over the last 10 years. The goal is to reduce problems and improve fusion results. Using extra hardware helps stabilize the spine while it’s healing.

You were lucky to have a good result. Many patients with bone graft fusions ended up with a failed fusion. Motion at the fusion site caused problems with spinal instability and back pain.

A bone graft is still used today. Bone removed during the operation is shaved or ground up and placed inside the cage. Bone grows around the cage giving a good, solid fusion. At the same time the cage holds the bones apart like the disc used to do.

Overall results are better in the short- and long-run. Now researchers are trying smaller incisions for spinal surgery. The goal is less damage to the soft tissues and nerves.

Anterior lumbar interbody fusion or ALIF is used most often when patients have a single degenerative disc. The damaged disc is removed. Bone graft with or without implanted cages is used to fuse the two vertebrae together.

Some patients are surprised that they aren’t pain free right away. Most patients obtain pain relief in the first six weeks. They continue to get better during the first six months.

Studies show a success rate for ALIF between 73 and 86 percent. Success is defined as a solid fusion with pain relief. It doesn’t always mean the patient got complete pain reduction.

A group of physical therapists from around the U.S. have been working on this problem. They would like to find a way to predict who can get better doing stabilization exercises (SEs). They are also looking for clues to predict who won’t get better.

So far they’ve found four factors related to success with SEs. they call this the Prediction Rule of Success. They’ve also found a group of factors they call the Prediction Rule of Failure. Here’s what they are:

Factors Predicting Success

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.