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The following documents attempt to explain what can cause Low Back Pain, how it is diagnosed, and describe the treatment options available. You may want to also download the animation player (zipped 208K) for Windows to view the animations. In addition, there is a fully functional demo available (zipped 1.4 meg) for download that demonstrates the stand alone commercial version of "A Patient's Guide to Low Back Pain.

• Introduction
• Anatomy
• Symptoms
• Diagnosis
• Treatment

In addition, Medical Multimedia Group invites anyone with specific questions concerning this syndrome, its diagnosis, or treatment to submit those questions for inclusion to the LBPFAQ.TXT. You will not receive a direct answer, but your question will be submitted for review and inclusion in the FAQ document. Comments by medical and non-medical folks will be added to the FAQ after review if deemed appropriate. Any physician, who actively treats patients with Low Back Pain, and would like to expand on the concepts presented in these pages, or give a differing view, is welcome to submit additional material for inclusion either to the Web Page or the FAQ.

• Frequently Asked Questions (LBPFAQ.TXT) document

This material does not constitute medical advice. It is intended for informational purposes only. NO ONE ASSOCIATED WITH MEDICAL MULTIMEDIA GROUP WILL ANSWER MEDICAL QUESTIONS VIA EMAIL. Please consult a physician for specific treatment recommendations.

Introduction

Back pain is the number one problem facing the workforce in the United States today. It is estimated that over 80 billion dollars is spent on back pain each year, and the cost is growing. Eighty percent of the population will suffer back pain at some time in their lives. These episodes usually occur during the ages of 30 to 50, the most productive period of most people's lives. Most episodes of low back pain are self limited, meaning that they will resolve no matter what the treatment is. But, a significant portion of these episodes can become chronic, meaning that they do not resolve and continue to cause pain and dysfunction indefinitely. Back pain is a common chronic problem for many people, no matter what their occupation. There is no quick fix or total cure for most back problems.

Over many years your back is subjected to repeated stress which may not result in pain at the time of injury. These repeated injuries add up, and eventually result in degeneration of the spine and low back pain. Most episodes of low back pain are at least partially the result of degenerative changes occuring in the back. There may be an acute injury associated with the individual episode, but the overall condition of the lumbar spine usually determines how fast one recovers and the risk of the condition becoming chronic. The goal of any treatment program should be to improve the current condition and to slow the progression of the degenerative process. The physician's role in the treatment of low back pain should be aimed at identifying significant problems that require immediate attention, and attempting to prevent chronic back problems by giving you the tools to prevent further injury. The goal of this presentation is to help you understand more about your back problem so that you can better make decisions and help yourself.

Anatomy

The parts of your spine and how they work

The Lumbar Spine (image 26K) is made up of the last five vertebra of the spine. The vertebrae are the bones of the spine. Their function is to provide support and protection to the spinal cord. The facet joints allow the vertebrae to be linked like a chain. They provide mobile connections between each vertebra. Like other joints in the body, the facet joints can be affected by arthritis. An intervertebral disk sits between each individual vertebra. The disk is actually a large, round ligament that connects the vertebrae. If we look at the disk in cross section, we see that it is made up of two parts. The annulus is the outer ring. It is the strongest part and is responsible for connecting the vertebrae. The nucleus pulposus is the soft, inner portion. This material is about the consistency of crabmeat and is responsible for the shock absorption properties of the spine. The nerve roots of the spine carry information between the lower extremities and the brain. They are sometimes involved with production of pain as well.

To better understand how the parts of the spine affect each other, we sometimes focus on a spinal segment (image 26K). A spinal segment is composed of: two vertebrae, the intervertebral disk between, and the two nerve roots that exit from that spinal level, one from each side. Notice how the facet joints fit together at each spinal segment. Understanding the anatomy in cross section is helpful as well.

Many of the problems that cause back pain are the result of injury and degeneration of the intervertebral disk. Degeneration is a process where wear and tear causes deterioration, like when your favorite jeans get old. The disk is subjected to different types of stress as we use our backs each day. The disk generally acts like a shock absorber. Bending over results in compression (.flc animation zipped 82K) of the disk, and also causes the disk to bulge backwards towards the spinal canal and nerves. The facet joints must also shift to allow the bending to occur.

The earliest changes that occur in the disk are tears in the annulus (image 18K) . These tears heal the same way tears in other ligaments do-by scar formation. Scar tissue is not as strong as normal tissue. Repeated episodes of injury lead to a disk that begins to degenerate. As the degeneration progresses the disk loses some of its water content. It becomes stiff and loses the ability to act as a shock absorber. The process may continue until the disk is collapsed. Bone spurs form as the body's response to this degeneration. Looking at our cross section of the spinal segment, we can watch the process of degeneration ( .flc animation zipped 392K).

The nucleus loses water content and begins to disrupt. Bony spurs form around both the disk and the facet joints. These spurs are thought to be the result of excess motion at the spinal segment. Eventually, bone spurs form around the nerves of the spine as well.

One of the most dramatic injuries to the lumbar spine is the Herniated Disk (.flc animation zipped 24K). In this injury, a tear in the annular ligament allows the nucleus pulposus to squeeze into the spinal canal. If the nerve root is compressed by the disk material, there is pain, numbness, and weakness in the areas supplied by the nerve.

Where does the pain come from in degenerative disk disease? The shift of one vertebra on another is referred to as Segmental Instability (.flc animation zipped 21K). This can result in pinching of the nerve root as it exits through the foramen. The excess motion can inflame the facet joints and cause mechanical pain from arthritis of the joints. Finally, the degenerating disk itself can become inflamed and cause mechanical pain. In the late stages of spinal degeneration, bony spurs from the degenerative process can cause a condition known as Spinal Stenosis (image 22K). The spinal canal becomes tight and presses on the nerve roots causing pain and nerve dysfunction in the legs.

Symptoms

How you perceive spine problems

Now let's use the information from the anatomy section to help understand the symptoms of low back pain.

Low back pain can be divided into two main types:

• Mechanical Type pain
• Compressive Type pain

Mechanical type back pain results from inflammation caused by irritation or injury to the disk, the facet joints, the ligaments, or the muscles of the back. A common cause of mechanical pain is disk degeneration. Mechanical type pain usually starts near the lower spine. Mechanical type pain (image 30K) may also spread to include the buttock and thigh areas. It rarely extends below the knee.

Compressive type pain (image 33K) occurs when the nerve roots that leave the spine are irritated or pinched. A common cause of compressive pain is a herniated disk. The nerves that leave the lower lumbar spine join to form the Sciatic Nerve (image 36K). This nerve provides sensation and controls the muscles of the lower leg. Pressure on the nerve roots of the lumbar spine can interfere with the normal function of the Sciatic Nerve. One of the earliest signs of pressure on a nerve root is numbness (image 30K) in the area supplied by the nerve. There is pain in the same area, usually extending below the knee to the foot. It is not unusual for the back itself to be painless. Finally, the muscles that the nerve controls may become weak and the reflexes disappear.

Spinal stenosis can also cause compressive type pain. In some people, degeneration of the spine can result in a narrowing of the spinal canal where the spinal nerves are located. This causes all of the nerves within the spinal canal to become inflamed, and fail to function properly. Numbness can involve both of the lower extremities. The numbness may become worse with activities such as walking. Pain can involve both of the lower extremities. The pain becomes worse with activities such as walking, and gets better after short periods of rest. Weakness of the muscles of both legs may also occur, and again this may get worse when activity increases.

The Cauda Equina Syndrome

WARNING!

In a very few cases, a disk herniation (image 20K) can be so big that it fills the entire spinal canal. The immediate pressure on the nerves at that level may cause paralysis of the muscles that control the bowels and bladder. If you lose control over your bowels or bladder, you should contact your physician immediately.

THIS IS AN EMERGENCY!

Diagnosis

How we look into your back problem

The first thing that must be done is to provide your doctor with a complete history of your back pain. After a history has been provided, your doctor will conduct a thorough physical exmination.

X-rays of your lower back will probably also be ordered at the initial office visit. X-rays show the bones of the lumbar spine. Most of the soft tissue structures of the spine do not show up. Still, much can be learned from the X-rays. Here we see X-rays taken of the same patient 20 years apart (image 46K), showing the degree of degeneration (image 69K) in the spinal segments during that time. X-rays are a first step in looking into any back problem and will help in deciding which other tests, if any, will be required.

There are many tests available to try and find out what is causing your low back pain.

The MRI (Magnetic Resonance Imaging) (image 59K) scan is the most common test used to evaluate the spine. The MRI scanner uses magnetic waves instead of radiation. Imagine if you could slice through the spine layer by layer and take pictures of each slice. That's exactly what the MRI scanner allows us to do. Multiple pictures of the spine are taken by the MRI scanner. This allows us to view not only the bones of the spine, but also the nerves and disks.

Slices can also be taken across the spine, giving a cross sectional view. The MRI scanner allows usto see the nerves and disk quite clearly. No special dyes or needles are necessary. Here we see a MRI cross section showing a fairly typical herniated disk side view (image 48K)and cross section view (image 40K).

The CAT Scan (Computer Assisted Tomography) (image 41K) is an X-ray test that is very similar to the MRI Scan. X-Ray slices can be taken across the spine, giving a cross sectional view. The CAT Scan shows the bones of the spine much better than the MRI Scan, and is useful when conditions that affect the bones of the spine are suspected. The CAT Scan is commonly combined with a Myelogram to give a better picture of the spinal nerves and help determine if there is pressure from Spinal Stenosis or a Herniated Disk.

A Myelogram (image 61K) is a test that involves placing dye into the spinal sac that shows up on X-Ray. Any abnormal indentation on the spinal sac may indicate that there is pressure on the nerves of the spine, such as that caused by a herniated disk.

The Discogram (image 102K) is a special test where dye is injected directly into the disk in the area of the Nucleus Pulposus. If the injection causes you to experience the same low back pain you have been complaining of, this suggests that the disk being tested is causing your pain. Plain Xrays and a CAT Scan can also be used to look at the disk, and may show whether or not the disk is ruptured.

An Electromyogram(EMG) (.flc animation zipped 81K) is a test that looks at the function of the nerve roots leaving the spine. The test is done by inserting tiny electrodes into the muscles of the lower extremity. By looking for abnormal electrical signals in the muscles, the EMG can show if a nerve is being irritated, or pinched as it leaves the spine. Think of how you test the wiring on a lamp. If you place a working bulb into the lamp, and the bulb lights up, you assume that the wiring is OK. But what if the bulb doesn't light up? You can safely assume that something is probably wrong with the wiring. Like the lamp is unplugged. Or a short circuit has occurred. By using the leg muscles like the light bulb in the lamp, the EMG is able to determine the condition of the nerves that supply those muscles, like the wiring on the lamp. If the EMG machine finds that the muscles (the light bulb) are not working properly, we can assume that the nerves (the wiring) must be getting pinched somewhere.

A Bone Scan (.flc animation zipped 60K) is used to help locate the affected area of the spine. In order to perform a Bone Scan, a radioactive chemical is injected into the bloodstream. The radioactive chemical attaches itself to areas of bone that are undergoing rapid changes for any reason. Areas of the skeleton that are undergoing rapid changes appear (image 26K)as dark areas on the film. Once the affected area is identified, other tests, such as the MRI Scan are done to look more closely at the specific area.

There are many possible causes (image 40K) of low back pain. Some of these causes are not related to degeneration of the spine. Blood tests to look for infection, or arthritis may be necessary. Problems originating in areas other than the spine may also cause back pain. These can include: aortic aneurysm, kidney problems, and stomach ulcers. These problems are just a few of the possibilities. Specific tests to rule out these possibilities may be suggested if your doctor feels that they are necessary.

Treatment

Options available to help you with your back problem.

The treatment of back pain ranges from simple reassurance that nothing is wrong to extremely delicate surgery. Each case is different and treatment must be individualized to meet the circumstances. Treatment falls into two major categories:

• Conservative treatment --- which includes exercise, medications, physical therapy, and other non-operative therapy.
• Surgical treatment --- which includes laminectomy, diskectomy, and spinal fusion in selected conditions.

Surgery is only necessary in a small number of patients. There is no one surgical procedure that is appropriate for all spine problems. If surgery is suggested for your problem, the best operation for your specific problem will be suggested.

Treatment for any back condition should involve two goals:

• To relieve the immediate problem
• To reduce the risk of re-injury

Exercise (image 40K) plays an important role in achieving both of these goals. Many studies have shown that people who exercise regularly have far fewer problems with back pain. Exercise stimulates the body's natural pain controlling hormones and actually decreases pain perception. A Physical Therapist (image 55K) may be contacted to help you with your exercise program. The Physical Therapist will also teach you about ways to prevent further back injury.

Medications (image 75K) should be used wisely!

SOME MEDICATIONS ARE HIGHLY ADDICTIVE!

NO PAIN MEDICATION WILL CONTROL CHRONIC PAIN IF USED FOR PROLONGED PERIODS.

No medication will cure back pain of degenerative origin. Medications are used to control: pain, inflammation, muscle spasm, and sleep disturbance.

If simple measures fail to control your back pain an Epidural Steroid Injection (ESI) (.flc animation zipped 21K) may be suggested. Many different problems can cause inflammation of the nerves in the lumbar spine. The epidural steroid injection involves placing a small amount of cortisone into the bony spinal canal. Cortisone is a very powerful anti-inflammatory drug that may bring the inflammation surrounding the nerves under control and ease your pain. The epidural steroid injection is not always successful. Most centers report a 40%-50% success rate. These injections are reserved for cases where all other conservative measures have failed, or as a last attempt to postpone surgery.

One of the most common surgical procedures is a diskectomy (.flc animation zipped 377K), the removal of a herniated disk to relieve pressure on a nerve root. The first step is to remove a portion of the lamina of the vertebra. The lamina is the portion of the vertebra that forms the roof over the spinal nerves. Removing a portion of the lamina creates a window into the spine. The nerves are then pulled to the side so that the herniated disk can be seen. Small instruments are then used to remove the herniated disk material. Most of the Nucleus Pulposus is removed to prevent the disk from herniating again. Once the disk material is removed, the nerves are free of pressure and irritation. The lamina and the area of the disk that is removed fill with scar tissue very rapidly.

When the major problem appears to be Spinal Stenosis the spinal canal needs to be made larger. This is usually done by performing a complete laminectomy (.flc animation zipped 405K). Remember, the lamina is the back portion of the spine and forms the roof of the spinal canal. Laminectomy means remove the lamina. Things may be clearer if we refer to the cross section view. Removing the lamina allows more room for the nerves, and enables the surgeon to remove bone spurs around the nerves. This allows more room for the nerves of the spine and reduces the irritation and inflammation on the spinal nerves. The bone does not grow back. Instead, scar tissue replaces the lamina and protects the spinal nerves.

If your back problem is the result of segmental instability, a spinal fusion (image 66K) may be suggested. A spinal fusion involves placing a bone graft between two or more vertebrae, causing the vertebrae to grow together, or fuse. The bone graft (image 31K) is usually taken from the bones of the pelvis at the time of surgery. There are two types of spinal fusions:

• Posterior fusion
• Interbody fusion

In the posterior fusion (image 31K), the bone graft is placed on the back side of the vertebrae. During the healing process the vertebrae then fuse. This creates a solid block of bone between the vertebrae. The interbody fusion (image 30K) differs by placing the bone graft between the vertebrae, where the disk has been removed. Once again, the healing process causes the vertebrae to fuse, creating a solid block of bone between the fused vertebrae. Both fusions accomplish the same thing. The vertebrae grow together, or fuse into one bone. The goal of a spinal fusion is to stop the motion from segmental instability. This reduces the mechanical back pain and impingment on the nerve root from excess motion.

Last updated 05/07/95

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