A Patient’s Guide to Anterior Lumbar Fusion with Cages

Introduction

Anterior lumbar fusion is an operation done on the front (the anterior region) of the lower spine. Fusion surgery helps two or more bones grow together into one solid bone. Fusion cages are new devices, essentially hollow screws filled with bone graft, that help the bones of the spine heal together firmly. Surgeons use this procedure when patients have symptoms from disc degeneration, disc herniation, or spinal instability.

This guide will help you understand

• why the procedure becomes necessary
• what surgeons hope to achieve
• what to expect during your recovery

Anatomy

What parts of the spine are involved?

Since the surgeon needs to reach the front of the spine, this operation is done through the abdomen. The main structures involved in this procedure are the vertebral bodies and the intervertebral discs.

The vertebral bodies are the large blocks of bone that make up the front section of each vertebra. The intervertebral discs are the cushions between each pair of vertebrae.

The fusion cages help separate the vertebral bodies, taking pressure off the spinal nerves wherethey travel from the spinal canal through openings called the neural foramen.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Rationale

What do surgeons hope to achieve?

In most cases, this procedure is used to stop symptoms from lumbar disc disease. The intervertebral discs in the spine degenerate as a natural part of aging. Daily wear and tear and certain types of vibration can also speed up degeneration in the spine. In addition, strong evidence suggests that smoking speeds up degeneration of the spine. Scientists have also found links among family members, showing that genetics plays a role in how fast these changes occur. When degeneration occurs, a problem disc begins to collapse, and the space decreases between the vertebrae.

Related Document: A Patient’s Guide to Lumbar Degenerative Disc Disease

When this happens, the opening around the spinal nerves (the neural foramen) narrows and may begin to put pressure on the nerves. The long ligaments in the spine slacken. They may even buckle and put pressure on the spinal nerves. The outer rings of the disc, the annulus, weaken and develop small cracks. The nucleus in the center of the disc presses on the weakened annulus and may actually squeeze through the annulus and press on ligaments or nerves. Fragments of the disc that press against the outer annulus and spinal nerves can be a source of pain, numbness, and weakness. Pressure on the spinal nerves can also produce problems with the bowels and bladder, requiring emergency surgery.

View animation of degeneration

A fusion operation can reduce or eliminate the pain caused by a problem disc. If the fusion is successful, the vertebrae that are fused together no longer move against one another. Instead, they move together as one unit. This prevents the disc from causing pain.

Fusion cages are also designed to separate and hold the vertebrae apart. Enlarging the space between two vertebrae widens the opening of the neural foramina, taking pressure off the spinal nerves that pass through them. Also, the extra space pulls taut the ligaments inside the spinal canal so they don’t buckle into the spinal canal.

View animation of regaining disc height

Fusion cages are most commonly made of metal, graphite, or bone. Many of these cages are shaped like cylinders. A few are rectangular in shape. They are usually threaded like a screw on the outside and hollow on the inside. The main purpose of the cage, regardless of the shape or material, is to hold the two vertebrae apart while the fusion becomes solid.

The surgeon packs the hollow center of the cage with bone. The graft is commonly taken from another part of the body, usually the top of the pelvis bone. Bone taken from another part of your own body is called an autograft. There is a risk of pain, infection, or weakness in the area where the graft is taken.

A new method to avoid this problem is with a bone graft substitute. By using gene therapy, scientists have produced bone graft substitutes called growth factors. These growth factors are natural proteins found in the human body. Genetic engineers have been able to clone proteins known as bone morphogenic proteins (BMPs). These proteins are then made available as powder, small particles, or chips. Hormones that circulate in the bloodstream act on the BMP molecules, causing them to build new bone tissue.

The growth factor that is approved for lumbar fusion with titanium cages is BMP-2. Substituting BMP-2 for an autograft eliminates the complications that go with harvesting autograft material from the patient’s own body. This allows for shorter operation times, less loss of blood during surgery, and quicker recovery times for patients. New research shows that BMP-2 is at least as good as, and maybe even better than, autograft for anterior lumbar fusion with cages.

The surgeon packs the hollow center of the fusion cages with bone graft, either in the form of an autograft or bone graft substitute. Two cages are placed side by side within the disc. The cages spread the vertebrae apart, and the threads bind the vertebrae to keep them from moving. After implanting the cages, most surgeons attach metal hardware on the vertebrae to rigidly lock them in place. This helps the bone graft heal, fusing the vertebrae together.

Once the bones fuse, they are prevented from moving against one another. This helps relieve the mechanical pain, which occurs in the moving parts of the back. Fusion also prevents additional wear and tear on the structures inside the section that was fused. By fusing the bones together, surgeons hope to reduce future problems at the spinal segment.

Preparations

How will I prepare for surgery?

The decision to proceed with surgery must be made jointly by you and your surgeon. You should understand as much about the procedure as possible. If you have concerns or questions, talk to your surgeon.

Once you decide on surgery, your surgeon may suggest a complete physical examination by your regular doctor. This exam helps ensure that you are in the best possible condition to undergo the operation.

On the day of your surgery, you will probably be admitted to the hospital early in the morning. You shouldn’t eat or drink anything after midnight the night before.

Surgical Procedure

What happens during the operation?

Traditionally, this operation requires a sizeable abdominal incision. Recently, however, surgeons have begun using a laparoscope in this operation. A laparoscope is a small television camera that lets the surgeon see inside the abdominal cavity to perform the operation. Several much smaller abdominal incisions are needed in the laparoscopic method. The smaller incisions allow patients to begin moving sooner and healing faster. However, performing anterior lumbar fusion with a laparoscope is difficult. It isn’t the right choice for all fusion surgeries.

Patients are positioned on their backs with a pad placed under the low back. They are given general anesthesia to put them to sleep. As they sleep, their breathing may be assisted with a ventilator. A ventilator is a device that controls and monitors the flow of air to the lungs.

In the traditional method, an incision is made through one side of the abdomen. Organs and blood vessels are gently moved aside to expose the front of the lumbar spine.

The problem disc is located with a fluoroscope, a special X-ray that shows images on a TV screen. The surgeon drills two large holes horizontally through the front of the disc. The fusion cages are sized to fit into the newly drilled holes. Bone graft may be taken from the top of the pelvis. The other option is for the surgeon to use a bone graft substitute. The bone graft material is packed into the hollow cages. Then the surgeon screws the cages into the holes in the disc. The threads of the cages clinch the vertebrae above and below, holding them rigidly in place. The fluoroscope is used to check the position and fit of the cages.

As mentioned earlier, the surgeon may also fix the vertebrae in place using metal screws or plates. One option is screwing a strap of metal across the front of the spine. A second method involves additional surgery through the low back. This may be done on the same day or during a later surgery. Metal plates or screws applied through the back of the spine lock the two vertebrae and prevent them from moving. This protects the graft so it can heal better and faster.

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

A drainage tube may be placed in the wound. The muscles and soft tissues are put back in place, and the skin is stitched together. The surgeon may place the patient in a rigid brace.

The threaded cages rigidly connect the vertebrae above and below. Small openings in the surface of the cages allow the bone graft inside to contact the surfaces of both vertebrae. As the new bone inside the cages heals to the nearby vertebrae, the two vertebrae become rigidly fused into one solid bone.

Complications

What might go wrong?

As with all major surgical procedures, complications can occur. Some of the most common complications following anterior lumbar fusion with cages include

• problems with anesthesia
• thrombophlebitis
• infection
• nerve damage
• blood vessel damage
• problems with the graft or hardware
• nonunion
• ongoing pain

This is not intended to be a complete list of the possible complications.

Problems with Anesthesia

Problems can arise when the anesthesia given during surgery causes a reaction with other drugs the patient is taking. In rare cases, a patient may have problems with the anesthesia itself. In addition, anesthesia can affect lung function because the lungs don’t expand as well while a person is under anesthesia. Be sure to discuss the risks and your concerns with your anesthesiologist.

Thrombophlebitis (Blood Clots)

View animation of pulmonary embolism

Thrombophlebitis, sometimes called deep venous thrombosis (DVT), can occur after any operation. It occurs when the blood in the large veins of the leg forms blood clots. This may cause the leg to swell and become warm to the touch and painful. If the blood clots in the veins break apart, they can travel to the lung, where they lodge in the capillaries and cut off the blood supply to a portion of the lung. This is called a pulmonary embolism. (Pulmonary means lung, and embolism refers to a fragment of something traveling through the vascular system.) Most surgeons take preventing DVT very seriously. There are many ways to reduce the risk of DVT, but probably the most effective is getting you moving as soon as possible. Two other commonly used preventative measures include

• pressure stockings to keep the blood in the legs moving
• medications that thin the blood and prevent blood clots from forming

Infection

Infection following spine surgery is rare but can be a very serious complication. Some infections may show up early, even before you leave the hospital. Infections on the skin’s surface usually go away with antibiotics. Deeper infections that spread into the bones and soft tissues of the spine are harder to treat. They may require additional surgery to treat the infected portion of the spine.

Nerve Damage

Any surgery that is done near the spinal canal can potentially cause injury to the spinal cord or spinal nerves. Injury can occur from bumping or cutting the nerve tissue with a surgical instrument, from swelling around the nerve, or from the formation of scar tissue. An injury to the spinal cord or spinal nerves can cause muscle weakness and a loss of sensation to the areas supplied by the nerve.

Blood Vessel Damage

The abdominal aorta (the largest artery in the body) and the large veins that accompany it run in front of the spine as they split to run to each leg. These vessels must be moved aside to perform the anterior cage procedure. Because of this, the vessels may be injured, causing bleeding. When the procedure is performed using the laparoscope, too much bleeding may require opening the abdomen with a larger incision to repair the injured vessels.

Problems with the Graft or Hardware

Fusion surgery with cages requires bone grafting. The graft is commonly taken from the top rim of the pelvis (autograft). As mentioned earlier, there is a risk of pain, infection, or weakness in the area where the graft is taken. These risks are avoided when a bone graft substitute, such as BMP-2, is used in place of an autograft.

After the cages are in place, the surgeon checks their position before completing the surgery. However, the cages may shift slightly soon after surgery to the point that they are no longer able to hold the spine stable. Abnormal or excessive loads on the spine, for example from heavy lifting or carrying or from the impact of jumping from a high surface, can cause the cages to collapse. This shifting or collapsing of the cages can cause injury to the nearby tissues. If this happens, a second surgery may be needed to replace the cages and to apply additional instrumentation to lock the spine firmly in place.

Hardware can also cause problems. Screws or pins may loosen and irritate the nearby soft tissues. Also, the metal plates can sometimes break. If this happens, the surgeon may suggest another surgery either to take out the hardware or to add more hardware to solve the problem.

Nonunion

Sometimes the bones do not fuse as planned. This is called a nonunion, or pseudarthrosis. (The term pseudarthrosis means false joint.) When more than one level of the spine is fused at one time, there is a greater chance that nonunion will occur. Fusion of more than one level means two or more consecutive discs are removed and replaced with bone graft. If the joint motion from a nonunion causes pain, you may need a second operation.

In the second procedure, the surgeon may have to replace the cages. Metal plates and screws may also be added to rigidly secure the bones so they will fuse.

Ongoing Pain

Anterior lumbar fusion with cages is a complex surgery. Not all patients get complete pain relief with this procedure. As with any surgery, you should expect some pain afterward. If the pain continues or becomes unbearable, talk to your surgeon about treatments that can help control your pain.

After Surgery

What happens after surgery?

Patients are sometimes placed in a rigid body brace after surgery. This brace may not be needed if the surgeon attached metal hardware to the spine during the surgery.

Patients usually stay in the hospital after surgery for up to one week. During this time, a physical therapist helps patients learn safe ways to move, dress, and do activities without putting extra strain on the back. Patients may be instructed to use a walker for the first day or two. Before going home, patients are shown how to control pain and avoid problems.

Patients are able to return home when their medical condition is stable. However, they are usually required to keep their activities to a minimum in order to give the graft time to heal. Patients are cautioned against bending forward, lifting, twisting, driving, and prolonged sitting for up to six weeks. Activities and exercises that cause the spine to bend back place hazardous stress on the cages and should be avoided for at least six months. Outpatient physical therapy usually begins a minimum of six weeks after the date of surgery.

Rehabilitation

What should I expect as I recover?

Rehabilitation after anterior lumbar fusion with cages can be a slow process. Many surgeons prescribe outpatient physical therapy beginning a minimum of six weeks after surgery. This delay is needed to make sure the fusion is taking. You will probably need to attend therapy sessions for two to three months, and you should expect full recovery to take up to eight months. However, therapy can usually progress faster for patients who had fusion with instrumentation.

At first, treatments help control pain and inflammation. Ice and electrical stimulation treatments are commonly used to help with these goals. Your therapist may also use massage and other hands-on techniques to ease muscle spasm and pain.

Active treatments are slowly added. These include exercises for improving heart and lung function. Short, slow walks are generally safe to start with. Swimming and use of a stairclimbing machine are helpful in the later phases of treatment. Therapists also teach specific exercises to help tone and control the muscles that stabilize the low back.

Your therapist also works with you on how to move and do activities. This form of treatment, called body mechanics, helps you develop new movement habits. This training helps you keep your back in safe positions as you go about your work and daily activities. Training includes positions you use when sitting, lying, standing, and walking. You’ll also work on safe body mechanics with lifting, carrying, pushing, and pulling.

As your condition improves, the therapist tailors your program to help prepare you to go back to work. Some patients are not able to go back to a previous job that requires strenuous tasks. Your therapist may suggest changes in job tasks that enable you to go back to your previous job or to do alternate forms of work. You’ll learn to do these tasks in new ways that keep your back safe and free of strain.

Before your therapy sessions end, your therapist will teach you ways to avoid future problems.

A Patient’s Guide to Lumbar Disc Herniation

Introduction

Although people often refer to a disc herniation as a slipped disc, the disc doesn’t actually slip out of place. Rather, the term herniation means that the material at the center of the disc has squeezed out of its normal space. This condition mainly affects people between 30 and 40 years old.

This guide will help you understand

• how the problem develops
• how doctors diagnose the condition
• what treatment options are available

Anatomy

What parts of the spine are involved?

The human spine is formed by 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to form the spinal column. The spinal column gives the body its form. It is the body’s main upright support. The section of the spine in the lower back is known as the lumbar spine.

The lumbar spine is made up of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. These five vertebrae line up to give the low back a slight inward curve. The lowest vertebra of the lumbar spine, L5, connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the two pelvic bones. Some people have an extra, or sixth, lumbar vertebra. This condition doesn’t usually cause any particular problems.

Intervertebral discs separate the vertebrae. The discs are made of connective tissue. Connective tissue is the material that holds the living cells of the body together. Most connective tissue is made of fibers of a material called collagen. These fibers help the disc withstand tension and pressure.

A disc is made of two parts. The center, called the nucleus, is spongy. It provides most of the disc’s ability to absorb shock. The nucleus is held in place by the annulus, a series of strong ligament rings surrounding it. Ligaments are connective tissues that attach bones to other bones.

Healthy discs work like shock absorbers to cushion the spine. They protect the spine against the daily pull of gravity. They also protect it during strenuous activities that put strong force on the spine, such as jumping, running, and lifting.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Causes

Why do I have this problem?

Herniation occurs when the nucleus in the center of the disc pushes out of its normal space. The nucleus presses against the annulus, causing the disc to bulge outward. Sometimes the nucleus herniates completely through the annulus and squeezes out of the disc.

Although daily activities may cause the nucleus to press against the annulus, the body is normally able to withstand this pressure. However, as the annulus ages, it tends to crack and tear. It is repaired with scar tissue. This process is known as degeneration. Over time, the annulus weakens, and the nucleus may begin to herniate (squeeze) through the damaged annulus. At first, the pressure bulges the annulus outward. Eventually, the nucleus may herniate completely through the outer ring of the disc.

Related Document: A Patient’s Guide to Lumbar Degenerative Disc Disease

Vigorous, repetitive bending, twisting, and lifting can place abnormal pressure on the shock-absorbing nucleus of the disc. If great enough, this increased pressure can injure the annulus, leading to herniation.

A lumbar disc can also become herniated during an acute (sudden) injury. Lifting with the trunk bent forward and twisted can cause a disc herniation. A disc can also herniate from a heavy impact on the spine, such as falling from a ladder and landing in a sitting position.

Herniation causes pain from a variety of sources. It can cause mechanical pain. This is pain that comes from the parts of the spine that move during activity, such as the discs and ligaments. Pain from inflammation occurs when the nucleus squeezes through the annulus. The nucleus normally does not come in contact with the body’s blood supply. However, a tear in the annulus puts the nucleus at risk for contacting this blood supply. When the nucleus herniates into the torn annulus, the nucleus and blood supply meet, causing a reaction of the chemicals inside the nucleus. This produces inflammation and pain. A disc herniation may also put pressure against a spinal nerve. Pressure on an irritated or damaged nerve can produce pain that radiates along the nerve. This is called neurogenic pain.

Symptoms

What does the condition feel like?

Many cases of lumbar disc herniation result from degenerative changes in the spine. The changes that eventually lead to a disc herniation produce symptoms gradually. At first, complaints may only be dull pain centered in the low back, pain that comes and goes over a period of a few years. Doctors think this is mainly from small tears in the annulus. Larger cracks in the annulus may spread pain into the buttocks or lower limbs.

When the disc herniates completely through the annulus, it generally causes immediate symptoms, with sharp pain that starts in one hip and shoots down part or all of the leg. Commonly, patients no longer feel their usual back pain, only leg pain. This is likely because painful tension on the annulus releases when the nucleus pushes completely through.

Disc herniations produce inflammation when the nucleus comes in contact with the body’s blood supply (mentioned earlier). The inflammation can be a source of throbbing pain in the low back and may spread into one or both hips and buttocks.

A herniated disc can press against a spinal nerve, producing symptoms of nerve compression. Nerve pain follows known patterns in the lower limbs. It can be felt on the side of the upper thigh, in the calf, or even in the foot and toes.

Pressure on the nerve can also cause sensations of pins, needles, and numbness where the nerve travels down the lower limbs. If this happens, a person’s reflexes slow. The muscles controlled by the nerve weaken, and sensation in the skin where the nerve goes is impaired.

Rarely, symptoms involve changes in bowel and bladder function. A large disc herniation that pushes straight back into the spinal canal can put pressure on the nerves that go to the bowels and bladder.

The pressure may cause low back pain, pain running down the back of both legs, and numbness or tingling between the legs in the area you would contact if you were seated on a saddle. The pressure on the nerves can cause a loss of control in the bowels or bladder. This is an emergency. If the pressure isn’t relieved, it can lead to permanent paralysis of the bowels and bladder. This condition is called cauda equina syndrome. Doctors recommend immediate surgery to remove pressure from the nerves.

Diagnosis

How do doctors diagnose the problem?

Diagnosis begins with a complete history and physical exam. Your doctor will ask questions about your symptoms and how your problem is affecting your daily activities. These will include questions about where you feel pain and whether you have numbness or weakness in your legs. Your doctor will also want to know what positions or activities make your symptoms worse or better. Doctors rely on your report of pain to get an idea which disc is causing problems and if a nerve is being squeezed.

Then the doctor examines you to determine which back movements cause pain or other symptoms. Your skin sensation, muscle strength, and reflexes are also tested.

X-rays are of minor help in diagnosing disc herniations. The discs don’t actually show up on X-rays. However, doctors can tell if the space between the vertebrae is smaller than normal. This can be an indication that wear and tear on one or more discs is causing problems. However, many peoples’ X-rays show degeneration of the discs. This is because degeneration in the discs is part of aging, like skin that wrinkles with time.

Computed tomography (a CT scan) may be ordered. This is a detailed X-ray that lets doctors see slices of the body’s tissue. The image can show if a herniated disc is putting pressure on a spinal nerve.

Doctors may combine the CT scan with myelography. To do this, a special dye is injected into the space around the spinal canal, called the the subarachnoid space. When the CT scan is performed, the dye highlights the spinal cord and nerves. The dye can improve the accuracy of a standard CT scan for diagnosing a herniated disc.

When more information is needed, your doctor may order magnetic resonance imaging (MRI). The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. It gives a clear picture of the discs and whether a herniation is present. Like the CT scan, this machine creates pictures that look like slices of the area your doctor is interested in. The test does not require special dye or a needle.

Doctors sometimes order a specialized X-ray test called discography. In this test, dye is injected into one or more discs. The dye is seen on X-ray and can give some information about the health of one or more discs. This test may be used when surgery is being considered to determine which disc is causing problems.

Doctors may also order electrical tests to locate more precisely which spinal nerve is being squeezed. Several tests are available to see how well the nerves are functioning, including the electromyography (EMG) test. This test measures how long it takes a muscle to work once a nerve signals it to move. The time it takes will be slower if a herniated disc has put pressure on a spinal nerve. Another test is the somatosensory evoked potential (SSEP) test. The SSEP is used to measure nerve sensations. These sensory impulses travel up the nerve, informing the body about sensations such as pain, temperature, and touch. The function of a nerve is recorded by an electrode placed over the skin in the area where the nerve travels. Doctors will often run these tests before performing surgery for a lumbar disc herniation.

Treatment

What treatment options are available?

Nonsurgical Treatment

Unless your condition is causing significant problems or is rapidly getting worse, most doctors will begin with nonsurgical treatment.

At first, your doctor may want your low back immobilized. Keeping the back still for a short time can calm inflammation and pain. This might include one or two days of bed rest. Lying on your back can take pressure off sore discs and nerves. However, most doctors advise against strict bed rest and prefer their patients to do ordinary activities using pain to gauge how much is too much. In rare cases in which bed rest is prescribed, it is usually used for a maximum of two days.

A back support belt is sometimes used for patients with lumbar disc herniation. The belt can help lower pressure inside the problem disc. Patients are encouraged to gradually discontinue wearing the support belt over a period of two to four days. Otherwise, their trunk muscles begin to rely on the belt and start to atrophy (shrink).

Doctors prescribe certain types of medication for patients with lumbar disc herniation. At first, you may be prescribed anti-inflammatory medications such as aspirin or ibuprofen. Severe symptoms that don’t go away may be treated with narcotic drugs, such as codeine or morphine. But narcotics should only be used for the first few days or weeks because they are addictive when used too much or improperly. Muscle relaxants may be prescribed if the low back muscles are in spasm. Pain that spreads down the leg is sometimes relieved with oral steroids taken in tapering dosages.

You may work with a physical therapist. Therapy treatments focus on relieving pain, improving back movement, and fostering healthy posture. A therapist can design a program to help you prevent future problems.

Some patients who continue to have symptoms are given an epidural steroid injection (ESI). Steroids are powerful anti-inflammatories. In an ESI, medication is injected into the space around the lumbar spinal nerves where they branch off of the spinal cord. This area is called the epidural space. Some doctors inject only a steroid. Most doctors, however, combine a steroid with a long-lasting numbing medication. Generally, an ESI is given only when other treatments aren’t working. But ESIs are not always successful in relieving pain. If they do work, they often provide only temporary relief.

Most people with a herniated lumbar disc get better without surgery. As a result, doctors usually have their patients try nonoperative treatments for at least six weeks before considering surgery. But when patients simply aren’t getting better, or if the problem is becoming more severe, surgery may be suggested.

Surgery

If the symptoms you feel are mild and there is no danger they’ll get worse, surgery is not usually recommended. However, if signs appear that pressure is building on the spinal nerves, surgery may be required, sometimes right away. The signs doctors watch for when reaching this decision include weakening in the leg muscles, pain that won’t ease up, and problems with the bowels or bladder.

Surgical treatment for lumbar disc herniation includes

• laminotomy and discectomy
• microdiscectomy
• posterior lumbar fusion

Laminotomy and Discectomy

The lamina forms a roof-like structure over the back of the spinal canal. In this procedure, a thumbnail-sized piece of the lamina is removed (laminotomy) so the surgeon can more easily take out the problem disc (discectomy). This procedure is mainly used when the herniated disc is putting pressure on a nerve and causing pain to spread down one leg.

Related Document: A Patient’s Guide to Lumbar Discectomy

Microdiscectomy

Microdiscectomy is becoming the standard surgery for lumbar disc herniation. The procedure is used when a herniated disc is putting pressure on a nerve root. It involves carefully taking out part of the problem disc (discectomy). By performing the operation with a surgical microscope, the surgeon only needs to make a very small incision in the low back. Categorized as minimally invasive surgery, this surgery is thought to be less taxing on patients. Advocates also believe that this type of surgery is easier to perform, that it prevents scarring around the nerves and joints, and that it helps patients recover more quickly.

Posterior Lumbar Fusion

Lumbar disc herniation causes mechanical pain, the type of pain caused by wear and tear in the parts of the lumbar spine. Fusion surgery is mainly used to stop movement of the painful area by joining two or more vertebrae into one solid bone. This keeps the bones and joints from moving, easing mechanical pain.

In posterior lumbar fusion, the surgeon lays small grafts of bone over the problem area on the back of the spinal column. Most surgeons will also apply metal plates and screws to prevent the problem vertebrae from moving. This protects the graft so it can heal better and faster.

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

Rehabilitation

What should I expect as I recover?

Nonsurgical Rehabilitation

Even if you don’t need surgery, your doctor may recommend that you work with a physical therapist. Patients are normally seen a few times each week for four to six weeks. In severe cases, patients may need a few additional weeks of care.

The first goal of treatment is to control symptoms. Your therapist will help you find positions and movements that ease pain. Treatments of heat, cold, ultrasound, and electrical stimulation may be used in the first few sessions. Lumbar traction may also be used at first to ease symptoms of lumbar disc herniation. In addition, your therapist may use hands-on treatments such as massage or spinal manipulation. These forms of treatment are mainly used to help reduce pain and inflammation so you can resume normal activity as soon as possible.

The therapist shows you how to keep your spine safe during routine activities. You’ll learn about healthy posture and how posture relates to the future health of your spine. You’ll learn about body mechanics, how the body moves and functions during activity. Therapists teach safe body mechanics to help you protect the low back as you go about your day. This includes the use of safe positions and movements while lifting and carrying, standing and walking, and performing work duties.

Next comes a series of strengthening exercises for the abdominal and low back muscles. Working these core muscles helps patients begin moving easier and lessens the chances of future pain and problems.

Aerobic exercises such as walking or swimming are used for easing pain and improving endurance.

Your therapist will work closely with your doctor and employer to help you get back on the job as quickly as reasonably possible. You may be required to do lighter duties at first, but as soon as you are able, you’ll begin doing your normal work activities. Your therapist can do a work assessment to make sure you’ll be safe to do your job. Your therapist may suggest changes that could help you work safely, with less chance of re-injuring your back.

A primary purpose of therapy is to help you learn how to take care of your symptoms and prevent future problems. You’ll be given a home program of exercises to continue improving flexibility, posture, endurance, and low back and abdominal strength. The therapist will also discuss strategies you can use if your symptoms flare up.

After Surgery

Rehabilitation after surgery is more complex. Some patients leave the hospital shortly after surgery. However, some surgeries require patients to stay in the hospital for a few days. Patients who stay in the hospital may visit with a physical therapist in the hospital room soon after surgery. The treatment sessions help patients learn to move and do routine activities without putting extra strain on the back.

During recovery from surgery, patients should follow their surgeon’s instructions about wearing a back brace or support belt. They should be cautious about overdoing activities in the first few weeks after surgery.

Many surgical patients need physical therapy outside of the hospital. They see a therapist for one to three months, depending on the type of surgery. At first, therapists may use treatments such as heat or ice, electrical stimulation, massage, and ultrasound to help calm pain and muscle spasm. They provide reassurance to help patients deal with fear and apprehension about pain. Then they teach patients how to move safely with the least strain on the healing back. Exercises are used to improve flexibility, strength, and endurance.

When your treatment is well under way, regular visits to the therapist’s office will end. The therapist will continue to be a resource for you. But you will be in charge of doing your exercises as part of an ongoing home program.

A Patient’s Guide to Lumbar Spondylolisthesis

Introduction

Normally, the bones of the spine (the vertebrae) stand neatly stacked on top of one another. Ligaments and joints support the spine. Spondylolisthesis alters the alignment of the spine. In this condition, one of the spine bones slips forward over the one below it. As the bone slips forward, the nearby tissues and nerves may become irritated and painful.

This guide will help you understand

• how the problem develops
• how doctors diagnose the condition
• what treatment options are available

Anatomy

What parts of the spine are involved?

The human spine is made up of 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column. The spinal column gives the body its form. It is the body’s main upright support. The section of the spine in the lower back is called the lumbar spine.

The lumbar spine is made of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. These five vertebrae line up to give the low back a slight inward curve. The lowest vertebra of the lumbar spine, L5, connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the two pelvic bones.

Each vertebra is formed by a round block of bone, called a vertebral body.

A circle of bone attaches to the back of the vertebral body. When the vertebrae are stacked on top of each other, these bony rings create a hollow tube. This tube, called the spinal canal, surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

The spinal cord only extends to L2. Below this level, the spinal canal encloses a bundle of nerves that goes to the lower limbs and pelvic organs. The Latin term for this bundle of nerves is cauda equina, meaning horse’s tail.

Two sets of bones form the spinal canal’s bony ring. Two pedicle bones attach to the back of each vertebral body. Two lamina bones complete the ring. The place where the lamina and pedicle bones meet is called the pars interarticularis, or pars for short. There are two such meeting points on the back of each vertebra, one on the left and one on the right. The pars is thought to be the weakest part of the bony ring.

Intervertebral discs separate the vertebral bodies. The discs normally work like shock absorbers. They protect the spine against the daily pull of gravity. They also protect the spine during strenuous activities that put strong force on the spine, such as jumping, running, and lifting.

The lumbar spine is supported by ligaments and muscles. The ligaments, which connect bones together, are arranged in layers and run in multiple directions. Thick ligaments connect the bones of the lumbar spine to the sacrum (the bone below L5) and pelvis.

Between the vertebrae of each spinal segment are two facet joints. The facet joints are located on the back of the spinal column. There are two facet joints between each pair of vertebrae, one on each side of the spine. A facet joint is made of small, bony knobs that line up along the back of the spine. Where these knobs meet, they form a joint that connects the two vertebrae. The alignment of the facet joints of the lumbar spine allows freedom of movement as you bend forward and back.

The anatomy of the lumbar spine is often discussed in terms of spinal segments. Each spinal segment includes two vertebrae separated by an intervertebral disc, the nerves that leave the spinal cord at that level, and the facet joints that link each level of the spinal column.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Causes

Why do I have this problem?

Spondylolisthesis may very rarely be congenital, which means it is present at birth. It can also occur in childhood as a result of injury. In older adults, degeneration of the disc and facet (spinal) joints can lead to spondylolisthesis.

Spondylolisthesis from degeneration usually affects people over 50 years old. This condition occurs in African Americans more often than in whites. Women are affected more often than men. The effect of the female hormone estrogen on ligaments and joints is to cause laxity or looseness. The higher levels of estrogen in women may account for the greater incidence of spondylolisthesis. Degenerative spondylolisthesis mainly involves slippage of L4 over L5.

In younger patients (under 20 years old), spondylolisthesis usually involves slippage of the fifth lumbar vertebra over the top of the sacrum. There are several reasons for this. First, the connection of L5 and the sacrum forms an angle that is tilted slightly forward, mainly because the top of the sacrum slopes forward. Second, the slight inward curve of the lumbar spine creates an additional forward tilt where L5 meets the sacrum. Finally, gravity attempts to pull L5 in a forward direction.

Facet joints are small joints that connect the back of the spine together. Normally, the facet joints connecting L5 to the sacrum create a solid buttress to prevent L5 from slipping over the top of the sacrum. However, when problems exist in the disc, facet joints, or bony ring of L5, the buttress becomes ineffective. As a result, the L5 vertebra can slip forward over the top of the sacrum.

A condition called spondylolysis can lead to the slippage that happens with spondylolisthesis. Spondylolysis is a defect in the bony ring of the spinal column. It affects the pars interarticularis, mentioned earlier. This defect is most commonly thought to be a stress fracture that happens from repeated strains on the bony ring. Participants in gymnastics and football commonly suffer these strains. Spondylolysis can lead to the spine slippage when a fracture occurs on both sides of the bony ring. This slippage is called spondylolisthesis. The slippage is graded from I through IV, one being mild, IV often causing neurological symptoms. The back section of the bony ring separates from the main vertebral body, so the injured vertebra is no longer connected by bone to the one below it. In this situation, the facet joints can’t provide their normal support. The vertebra on top is then free to slip forward over the one below.

View animation of spondylolisthesis

Related Document: A Patient’s Guide to Spondylolysis

A traumatic fracture in the bony ring can lead to slippage when the fracture goes completely through both sides of the bony ring. The facet joints are no longer able to provide a buttress, allowing the vertebra with the crack in it to slip forward. This is similar to what happens when spondylolysis (mentioned earlier) occurs on both sides of the bony ring, but in this case it happens all at once.

Degenerative changes in the spine (those from wear and tear) can also lead to spondylolisthesis. The spine ages and wears over time, much like hair turns gray. These changes affect the structures that normally support healthy spine alignment. Degeneration in the disc and facet joints of a spinal segment causes the vertebrae to move more than they should. The segment becomes loose, and the added movement takes an additional toll on the structures of the spine. The disc weakens, pressing the facet joints together. Eventually, the support from the facet joints becomes ineffective, and the top vertebra slides forward.

Symptoms

What does the condition feel like?

An ache in the low back and buttock areas is the most common complaint in patients with spondylolisthesis. Pain is usually worse when standing, walking, or bending backward and may be eased by resting or bending the spine forward. Leaning on a counter top, piece of furniture, or shopping cart are common ways to alleviate (reduce) the symptoms.

Spasm is also common in the low back muscles. The hamstring muscles on the back of the thighs may become tight.

The pain can be from mechanical causes. Mechanical pain is caused by wear and tear on the parts of the spine. When the vertebra slips forward, it puts a painful strain on the disc and facet joints.

Slippage can also cause nerve compression. Nerve compression is a result of pressure on a nerve. As the spine slips forward, the nerves may be squeezed where they exit the spine. This condition also reduces space in the spinal canal where the vertebra has slipped. This can put extra pressure on the nerve tissues inside the canal. Nerve compression can cause symptoms where the nerve travels and may include numbness, tingling, slowed reflexes, and muscle weakness in the legs.

Nerve pressure on the cauda equina (mentioned earlier), the bundle of nerve roots within the lumbar spinal canal, can affect the nerves that go to the bladder and rectum. When this happens, bowel and/or bladder function can be affected. The pressure may cause low back pain, pain running down the back of both legs, and numbness or tingling between the legs in the area you would contact if you were seated on a saddle.

Diagnosis

How do doctors diagnose the problem?

Diagnosis begins with a complete history and physical exam. Your doctor will ask questions about your symptoms and how your problem is affecting your daily activities. Your doctor will also want to know what positions or activities make your symptoms worse or better.

Next the doctor examines you by checking your posture and the amount of movement in your low back. Your doctor checks to see which back movements cause pain or other symptoms. Your skin sensation, muscle strength, and reflexes are also tested.

Doctors will usually order X-rays of the low back. The X-rays are taken with your spine in various positions. They can be used to see which vertebra is slipping and how far it has slipped.

If more information is needed, your doctor may order computed tomography (a CT scan). This is a detailed X-ray that lets the doctor see slices of the body’s tissue. If you have nerve problems, the doctor may combine the CT scan with myelography. To do this, a special dye is injected into the space around the spinal canal, the subarachnoid space. During the CT scan, the dye highlights the spinal nerves. The dye can improve the accuracy of a standard CT scan for diagnosing the health of the nerves.

Your doctor may also order a magnetic resonance imaging (MRI) scan. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. It can help in the diagnosis of spondylolisthesis. It can also provide information about the health of nerves and other soft tissues.

Treatment

What treatment options are available?

Nonsurgical Treatment

Studies have not been done yet to determine the best treatment for this condition. Conservative care is preferred, especially when the vertebra hasn’t slipped very far. Most patients with symptoms from degenerative spondylolisthesis do not need surgery and respond well to nonoperative care. Medications may be prescribed to help ease pain and muscle spasm. In some cases, the patient’s condition is simply monitored to see if symptoms improve.

Your doctor may ask that you rest your back by limiting your activities. This is to help decrease inflammation and calm muscle spasm. You may need to take time away from sports or other strenuous activities to give your back a chance to heal.

If your doctor diagnoses an acute pars fracture that has the potential to heal, it may be recommended that you wear a rigid back brace for two to three months. This usually occurs in children and teenagers who begin having back pain and see their doctor early on.

X-rays may show a fresh fracture of the pars area of the vertebra on one, or both, sides. A CT scan or bone scan may be recommended to determine if the fracture is likely to heal. If so, a brace is recommended. X-rays or a CT scan may be ordered in six to eight weeks to see if the fracture is healing. IF not, the brace will be discontinued.

Some patients who continue to have symptoms are given an epidural steroid injection (ESI). Steroids are powerful anti-inflammatories, meaning they reduce pain and swelling. In an ESI, medication is injected into the space around the lumbar nerve roots. This area is called the epidural space. Some doctors inject only a steroid. Most doctors, however, combine a steroid with a long-lasting numbing medication. Generally, an ESI is given only when other treatments aren’t working. But ESIs are not always successful in relieving pain. If they do work, they may only provide temporary relief.

Patients often work with a physical therapist. After evaluating your condition, your therapist can assign positions and exercises to ease your symptoms. Your therapist can design an exercise program to improve flexibility in your low back and hamstrings and to strengthen your back and abdominal muscles.

The use of a stationary bike can promote aerobic conditioning and puts you in the optimal position to open the spaces where the nerve roots exit. This type if exercise program can aid in reducing the painful symptoms.

Surgery

Surgery is used when the slip is severe and when symptoms are not relieved with nonsurgical treatments. Symptoms that cause an abnormal walking pattern, changes in bowel or bladder function, or steady worsening in nerve function require surgery. Deterioration of symptoms is common in patients with a history of significant neurologic symptoms who don’t have surgery to correct the problem.

If a reasonable trial of conservative care (three months or more) does not improve things and/or your quality of life is significantly reduced, then surgery may be the next best solution. The main types of surgery for spondylolisthesis include

• laminectomy (decompression)
• posterior fusion with or without instrumentation
• posterior lumbar interbody fusion

Laminectomy

When the vertebra slips forward, the nearby nerves that exit the spine can become pinched or irritated. In addition, the size of the spinal canal in the problem area shrinks, placing pressure on the nerves inside the canal. To fix this, the lamina of the bony ring is removed to ease pressure on the nerves. The procedure to remove the lamina and release pressure on the nerves is called laminectomy. Decompression alone is usually not advised. Studies show much better results when the operation is combined with a fusion of the involved vertebrae (see below).

Related Document: A Patient’s Guide to Lumbar Laminectomy

Posterior Fusion with Instrumentation

A spinal fusion is normally done immediately after laminectomy for spondylolisthesis. The fusion procedure is designed to fuse the two vertebrae into one bone and stop the slippage from worsening. The fusion is used to lock the vertebrae in place and stop movement between the vertebrae, easing mechanical pain. When combined with laminectomy surgery (mentioned earlier), fusion helps relieve nerve compression.

In this procedure, the surgeon lays small grafts of bone over the back of the problem vertebrae.

Sometimes fusion is done just with bone graft material. This is a fusion without fixation (non-instrumentation). Instrumentation is the use of metal plates or screws to stabilize the segment during healing. Most surgeons combine fusion with instrumentation to prevent the two vertebrae from moving. This protects the graft so it can heal better and faster.

Outcomes are improved when decompression is combined with fusion (compared with decompression alone). Fusion and functional improvement are even better when spinal instrumentation is used. There are fewer long-term problems with pain and pseudoarthrosis (formation of movement or false joints within the fusion).

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

Posterior Lumbar Interbody Fusion

When fusion surgery is needed for mild spondylolisthesis (up to 50 percent slippage), posterior lumbar interbody fusion may be considered. In this procedure, the problem vertebrae are fused from the anterior (front) and posterior (back). Combining fusion of both portions of the spine increases the fusion surface area and improves the fusion rate. The surgeon works from the back of the spine and removes the disc between the problem vertebrae. Bone graft material is inserted from the back of the spine into the space between the two vertebrae where the disc was removed (the interbody space). The graft may be held in place with a special fusion cage that spreads and holds the vertebrae apart. Surgeons usually apply some form of instrumentation (described above) on the back of the vertebrae. In some cases, additional strips of bone graft are placed along the back surfaces of the vertebrae to be fused. This increases the mechanical strength of the spine.

Related Document: A Patient’s Guide to Posterior Lumbar Interbody Fusion

Fusion with Biologics

New materials for fusion are being developed and tested. For example, bone morphogenetic proteins (BMP) mixed with bone graft in a putty is under investigation. This substance may help reduce the need for instrumentation with fusion.

BMP helps promote faster and more bone growth in the unstable spinal segment. Studies of safety and effectiveness of this material have been very favorable so far. Without the need to harvest bone graft and place instrumentation, surgical time is much less with BMP putty. And the fusion rate is much higher with BMP alone compared with fusion alone or fusion with fixation.

Motion-Sparing Technologies

The Food and Drug Administration (FDA) is reviewing the use of devices inserted without invasive surgery to limit vertebral motion. For example, a special titanium implant has been designed to fit between the spinous processes of the vertebrae in your lower back.

These motion-sparing devices are currently used with patients who have spinal stenosis (narrowing of the spinal canal or foramen). With spondylolisthesis, the goal is to reduce the load on the disc and facets while increasing the space inside the spinal canal and foramen, thus relieving your symptoms. The vertebral segment is stabilized enough to prevent further progression of the spondylolisthesis.

Rehabilitation

What should I expect as I recover?

Nonsurgical Rehabilitation

Back pain associated with spondylolisthesis will gradually improve in up to one-third of all patients. Slippage of one vertebra over the other does not increase in this group. Worsening of symptoms is not expected in patients who don’t have neurologic symptoms at the time of diagnosis.

Nonsurgical treatment for spondylolisthesis commonly involves physical therapy. Your doctor may recommend that you work with a physical therapist a few times each week for four to six weeks. In some cases, patients may need a few additional weeks of care.

The first goal of treatment is to control symptoms. Your therapist works with you to find positions and movements that ease pain. Treatments of heat, cold, ultrasound, and electrical stimulation may be used to calm pain and muscle spasm. Patients are shown how to stretch tight muscles, especially the hamstring muscles on the back of the thigh.

As patients recover, they gradually advance in a series of strengthening exercises for the abdominal and low back muscles. Working these core muscles helps patients move easier and lessens the chances of future pain and problems.

A primary purpose of therapy is to help you learn how to take care of your symptoms and prevent future problems. You’ll be given a home program of exercises to continue improving flexibility, posture, endurance, and low back and abdominal strength. The therapist will also describe strategies you can use if your symptoms flare up.

After Surgery

Rehabilitation after surgery is more complex. Patients who have surgery for spondylolisthesis usually stay in the hospital for a few days afterward.

Some surgeons require patients to wear a rigid brace or cast for up to four months after fusion surgery for spondylolisthesis. Patients who’ve had fusion surgery for a severe slip may also be required to stay off their feet for four months.

After lumbar fusion surgery for spondylolisthesis, patients must normally wait four months before beginning a rehabilitation program. This delay is needed to give the fusion a chance to start healing. Patients typically need to attend therapy sessions for six to eight weeks and should expect full recovery to take at least 12 months.

Ideally, patients are able to return to their previous activities. However, some patients may need to modify or discontinue certain activities to avoid future problems.

When your treatment is well under way, regular visits to the therapist’s office will end. The therapist will continue to be a resource for you. But you will be in charge of doing your exercises as part of an ongoing home program.

A Patient’s Guide to Lumbar Spondylolysis

Introduction

Spondylolysis happens when a crack forms in the bony ring on the back of the spinal column. Most commonly, this occurs in the low back. In this condition, the bone that protects the spinal cord fractures as a result of excessive or repeated strain. The area affected is called the pars interarticularis, so doctors sometimes refer to this condition as a pars defect.

This condition appears in six percent of children. It mainly affects young athletes who participate in sports in which the spine is repeatedly bent backwards, such as gymnastics, football, and karate.

Although spondylolysis can affect people of any age, children and adolescents are most susceptible. This is because their spines are still developing, and the pars is the weakest part of the vertebra. Placing extra strain on this area of the spine during childhood increases the chance that a pars defect will occur.

This guide will help you understand

• how the problem develops
• how doctors diagnose the condition
• what treatment options are available

Anatomy

What parts of the spine are involved?

The human spine is made up of 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column. The spinal column gives the body its form. It is the body’s main upright support. The section of spine in the lower back is called the lumbar spine.

Each vertebra is formed by a round block of bone, called a vertebral body. A circle of bone attaches to the back of the vertebra. When the vertebrae are stacked on top of each other, these bony rings create a hollow tube. This tube, called the spinal canal, surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

The protective ring that surrounds the spinal cord is a continuous ring of bone. Its sections include two pedicles which attach directly to the back of the vertebral body. Two laminae complete the ring.

The pedicles and laminae are two different areas of the bony ring. The area between them is not a joint. Rather, it is a location in the continuous ring of bone that doctors call the pars interarticularis, or “pars” for short. There are two such meeting points on the back of each vertebra, one on the left and one on the right. The pars is thought to be the weakest part of the bony ring.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Causes

What causes this problem?

Spondylolysis is thought to be caused by repeated strains that damage the lower spine over time. The repeated strains can eventually lead to an overuse injury in the pars interarticularis. The most common location for this to occur is in the lowest vertebra of the spine, which doctors call L5. This vertebra connects the spine to the pelvis. However, a problem with the pars can occur in any lumbar vertebra. It rarely happens in more than one vertebra at a time.

The vertebra initially responds to the abnormal strain by adding new bone cells around the injured area. But if the injuries happen faster than the body can keep up with needed repairs, a crack may form in the weakened bone. This is called a stress fracture. This type of fracture occurs in the pars, the area of bony ring between the pedicle and lamina.

The crack may affect only one side of the bony ring. However, it is equally common for the defect to occur on both sides. When this happens, the vertebra is no longer held firmly in place by the facet joints on the back of the ring. As a result, the vertebra is free to slip forward over the one below. This slippage, which is closely related to spondylolysis, is called spondylolisthesis.

Related Document: A Patient’s Guide to Spondylolisthesis

Spondylolysis commonly occurs in young gymnasts who regularly practice backbends as part of their routines. Football linemen and dancers are also prone to spondylolysis. Symptoms sometimes appear when an athlete quickly ramps up his or her training intensity, applies incorrect technique, or uses poor equipment.

Symptoms

What does the condition feel like?

People with spondylolysis may feel pain and stiffness in the center of the low back. Bending fully backward increases pain. Symptoms typically get worse with activity and go away with rest. Doctors refer to this type of back pain as mechanical pain because it most likely comes from excess movement between the vertebrae.

Individuals may eventually experience pain that radiates down one or both legs. This pain may come from pressure and irritation on the nerves that exit the spinal canal near the fracture. When nerve pressure in the low back causes leg pain, doctors refer it as neurogenic pain.

The cause of this nerve pressure is a result of the body’s attempt to heal the stress fracture. Over time, the healing process may cause a bump of extra cartilage to grow at the site where the bones are trying to heal the overuse injury. If too much cartilage builds up, this bump may intrude into the opening where the nerves exit the spine. The bump may squeeze the nerve. This can produce pain and weakness in the leg. Reflexes become slowed. The person may also notice a pins and needles sensation in the skin where the spinal nerve travels.

Diagnosis

How do doctors diagnose the problem?

Diagnosis begins with a complete history and physical exam. Your doctor will ask questions about your symptoms and how the problem is affecting your daily activities. You will be asked about your involvement in sports and your level of performance. Doctors may suspect a problem with spondylolysis in football linemen, gymnasts, and those in similar sports that require intensive levels of performance. Your doctor will also want to know what positions or activities make your symptoms worse or better.

Next the doctor examines you by checking your posture and the amount of movement in your low back. Your doctor checks to see which back movements cause pain or other symptoms. Your skin sensation, muscle strength, and reflexes are also tested.

Your doctor may order an X-ray of your low back. An angled, or oblique, view is often used to check for a pars fracture. The doctor traces around the vertebral body and bony ring on the X-ray film. The outline normally forms an image that looks like a small dog. When a crack is present, however, the dog will appear to have a collar around its neck. This is referred to as the Scotty dog sign. It confirms a diagnosis of spondylolysis.

Small defects in the bone may not show up on X-ray. Also, a recent stress fracture won’t always appear on X-ray. As a result, your doctor may order a bone scan to get the most accurate information. This involves injecting chemical “tracers” into your blood stream. The tracers then show up on special spine X-rays. The tracers collect in areas of extra stress to bone tissue, such as a stress fracture of the pars interarticularis.

Computed tomography (a CT scan) may be ordered. This is a detailed X-ray that lets doctors see slices of the body’s tissue. The image can show if the edges of the fractured bone have begun growing together. The scan shows whether the fracture is new or old, so doctors can decide which treatments will help the most.

When more information is needed, your doctor may order a magnetic resonance imaging (MRI) scan. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. It can help in the diagnosis of spondylolysis. It can also provide information about the health of nearby intervertebral discs and other soft tissues that don’t appear on X-rays.

Treatment

What treatment options are available?

Nonsurgical Treatment

Doctors often begin by prescribing nonsurgical treatment for spondylolysis. This is because symptoms from these stress fractures often resolve with rest or bracing. In some cases, doctors simply monitor their patients’ condition to see if symptoms improve. An X-ray may be taken every few months to check how well the area is healing.

If the doctor feels that the problem is due to a recent fracture, you may be placed in a rigid back brace or cast for three to four months. Keeping the spine from moving can help ease pain and inflammation. It can also improve the chances the bones will grow back together. Most people who require a brace or cast overcome symptoms and are able to eventually get back to activities free of pain. This can happen even when follow-up tests show that the bones haven’t completely healed.

Your doctor may ask that you rest your back by limiting your activities. The purpose of this is to help decrease inflammation and calm muscle spasm. You may need to take some time away from your sport, especially if it requires repeated back bending. This gives your back a chance to heal. Most patients who follow these measures get better. Patients are rarely counseled to completely discontinue participating in their sport, and only in severe cases.

Patients often work with a physical therapist. After evaluating your condition, a therapist can assign positions and exercises to ease your symptoms. The therapist may design an exercise program to improve the strength and control of your back and abdominal muscles. By watching you perform your sport activity, your therapist can suggest style, technique, or equipment changes to improve your performance and prevent future problems.

Surgery

Most patients with spondylolysis do not require surgery. When symptoms are not relieved with nonsurgical treatments, however, patients may require surgery. The main types of surgery for spondylolysis include

• laminectomy
• posterior lumbar fusion

Laminectomy

Nerve compression can cause considerable pain and symptoms. If too much cartilage builds up where the fractured bones are trying to heal, the nerve that passes near the injured bone may get squeezed, as described earlier. To fix this, a section of the bony ring is removed to take pressure off the nerve. The procedure to remove the lamina from the bony ring and release pressure on the nerve is called laminectomy.

Related Document: A Patient’s Guide to Lumbar Laminectomy

Posterior Lumbar Fusion

A spinal fusion may be required after a surgeon performs a laminectomy procedure. Fusion is recommended when a spinal segment (a set of vertebrae) has become too loose or unstable.

A spinal fusion allows two or more bones to grow together, or fuse, into one solid bone. This keeps the bones and joints from moving. In this procedure, the surgeon lays small grafts of bone over the problem area on the back of the spine. Some surgeons also apply metal plates and screws to prevent the two vertebrae from moving. However, this practice is controversial because fusion occurs in about 90 percent of children with spondylolysis when the procedure is done without plates and screws.

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

Rehabilitation

What should I expect as I recover?

Nonsurgical Rehabilitation

Recovery from this condition is much like nonsurgical treatment mentioned earlier. Once you have rested your back to allow it to heal, your doctor may recommend that you work with a physical therapist a few times each week for four to six weeks. In severe cases, patients may need a few additional weeks of physical therapy.

The first goal of treatment is to control symptoms. The therapist works with you to find positions and movements that ease pain. Treatments of heat, cold, ultrasound, and electrical stimulation may be used to calm pain and muscle spasm.

As you recover, you will gradually advance in a series of strengthening exercises for the abdominal and low back muscles. Working these core muscles helps patients begin moving easier and lessens the chances of future pain and problems.

When needed, a therapist can work closely with a sports coach on strategies for a patient’s safe return to his or her sport. The two may provide suggestions on technique, equipment, and training frequency and intensity.

If the patient is a working adult, the therapist may also work with the patient’s doctor and employer to help the patient get back on the job as quickly as reasonably possible. The patient may be required to do lighter duties at first. As soon as the patient is able, he or she will do normal work activities. The therapist may also suggest changes that could help the patient work safely, with less chance of re-injuring his or her back.

A primary purpose of therapy is to help patients learn how to take care of their symptoms and prevent future problems. Patients are given a home program of exercises to continue improving flexibility, posture, endurance, and low back and abdominal strength. The therapist also describes strategies you can use if your symptoms flare up.

Most adolescents get better after wearing a brace or cast for three months. Even then, a CT scan sometimes shows an unhealed fracture. In these cases, however, symptoms often go away completely, allowing a safe return to sports. Patients do best when guided in a gradual manner with the supervision of a therapist and sports coach.

After Surgery

Rehabilitation after surgery is more complex. Some patients leave the hospital shortly after surgery. However, some surgeries require patients to stay in the hospital for a few days. Patients who stay in the hospital may visit with a physical therapist in the hospital room soon after surgery. The treatment sessions help patients learn to move and do routine activities without putting extra strain on the back.

During recovery from surgery, patients should follow their surgeon’s instructions about wearing a back brace or support belt. They should be cautious about overdoing activities in the first few weeks after surgery.

Many surgical patients need physical therapy outside of the hospital. Patients who’ve had lumbar fusion surgery normally need to wait at least six weeks before beginning a rehabilitation program. This delay gives the fusion a chance to start healing. Patients typically need to attend therapy sessions for six to eight weeks and should expect full recovery to take up to six months.

A Patient’s Guide to Lumbar Laminectomy

Introduction

Lumbar laminectomy is a surgical procedure to relieve pressure on the spinal nerves. Degeneration, or wear and tear, in the parts of the spine may narrow the spinal canal. This puts pressure on the nerves in the canal. This condition is called spinal stenosis. A laminectomy involves removing a section of the bony covering over the back of the spinal canal. This takes pressure off the spinal nerves.

This guide will help you understand

• why the procedure becomes necessary
• what surgeons hope to achieve
• what to expect as you recover

Anatomy

What parts of the spine are involved?

Surgeons perform lumbar laminectomy surgery through an incision in the low back. The surgery involves the pedicle and lamina bones. These bones attach to the back of the spinal column, forming a bony ring that encloses the spinal canal. Surgeons may remove bone spurs from the facet joints

along the back of the spine during the laminectomy procedure, taking pressure off the spinal nerves.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Rationale

What do doctors hope to achieve?

Lumbar laminectomy can alleviate the symptoms of spinal stenosis, a condition in which the spinal nerves become compressed inside the spinal canal. Wear and tear on the spine from aging and from repeated stresses and strains can cause a spinal disc to weaken.

The outer rim of the disc bulges outward, and the disc may eventually protrude or even rupture into the spinal canal, narrowing the size of the canal. As a result, the nerves inside the canal are squeezed, leading to symptoms of spinal stenosis.

Degeneration also causes bone spurs to develop. These spurs commonly occur around the facet joints and along the edges of the vertebrae. When these spurs point into the spinal canal, they may squeeze against the spinal nerves. In a laminectomy, the surgeon removes a section of the lamina bone and any bone spurs, taking pressure off the spinal nerves. This enlarges the spinal canal so the spinal nerves have more room.

Preparations

How will I prepare for surgery?

The decision to proceed with surgery must be made jointly by you and your surgeon. You should understand as much about the procedure as possible. If you have concerns or questions, talk to your surgeon.

Once you decide on surgery, your surgeon may suggest a complete physical examination by your regular doctor. This exam helps ensure that you are in the best possible condition to undergo the operation.

On the day of your surgery, you will probably be admitted to the hospital early in the morning. You shouldn’t eat or drink anything after midnight the night before.

Surgical Procedure

What happens during the operation?

Patients are given a general anesthesia to put them to sleep during most spine surgeries. As you sleep, your breathing may be assisted with a ventilator. A ventilator is a device that controls and monitors the flow of air to the lungs.

Some surgeons have begun using spinal anesthesia in place of general anesthesia. Spinal anesthesia is injected in the low back into the space around the spinal cord. This numbs the spine and lower limbs. Patients are also given medicine to keep them sedated during the procedure.

This surgery is usually done with the patient kneeling face down in a special frame. The frame supports the patient so the abdomen is relaxed and free of pressure. This position lessens blood loss during surgery and gives the surgeon more room to work.

The surgeon makes a short incision down the middle of the low back. The skin and soft tissues are separated to expose the bones along the back of the spine. An X-ray of the low back ensures the surgeon works on the right vertebra. Some surgeons use a special surgical microscope during surgery to magnify the area they’ll be working on.

In a complete laminectomy, the spinous process (the bony projection off the back of the vertebra) and the lamina on each side are removed over the area where stenosis is occurring. To accomplish this, the surgeon cuts along the inside edge of the facet joint on each side and detaches the lamina bone completely from the pedicle bones. This opens a section in the bony ring. A small portion of the ligamentum flavum is removed. The ligamentum flavum runs all the way down the spinal canal between the lamina bones and the spinal cord. Removing a small section of this ligament exposes the nerves inside the spinal canal.

The surgeon may use small cutting instruments to carefully remove soft tissues near the spinal nerves. Then the surgeon takes out any disc fragments and scrapes off nearby bone spurs. In this way, the nerves inside the spinal canal are relieved of additional tension and pressure. The surgeon also enlarges the neural foramina, if needed. The neural foramina are the small openings between the vertebrae where the nerves travel out of the spinal canal.

The muscles and soft tissues are put back in place, and the skin is stitched together.

Complications

What might go wrong?

As with all major surgical procedures, complications can occur. Some of the most common complications following lumbar laminectomy include

• problems with anesthesia
• thrombophlebitis
• infection
• nerve damage
• segmental instability
• ongoing pain

This is not intended to be a complete list of the possible complications.

Problems with Anesthesia

Problems can arise when the anesthesia given during surgery causes a reaction with other drugs the patient is taking. In rare cases, a patient may have problems with the anesthesia itself. In addition, anesthesia can affect lung function because the lungs don’t expand as well while a person is under anesthesia. Be sure to discuss the risks and your concerns with your anesthesiologist.

Thrombophlebitis (Blood Clots)

View animation of pulmonary embolism

Thrombophlebitis, sometimes called deep venous thrombosis (DVT), can occur after any operation. It occurs when the blood in the large veins of the leg forms blood clots. This may cause the leg to swell and become warm to the touch and painful. If the blood clots in the veins break apart, they can travel to the lung, where they lodge in the capillaries and cut off the blood supply to a portion of the lung. This is called a pulmonary embolism. (Pulmonary means lung, and embolism refers to a fragment of something traveling through the vascular system.) Most surgeons take preventing DVT very seriously. There are many ways to reduce the risk of DVT, but probably the most effective is getting you moving as soon as possible. Two other commonly used preventative measures include

• pressure stockings to keep the blood in the legs moving
• medications that thin the blood and prevent blood clots from forming

Infection

Infection following spine surgery is rare but can be a very serious complication. Some infections may show up early, even before you leave the hospital. Infections on the skin’s surface usually go away with antibiotics. Deeper infections that spread into the bones and soft tissues of the spine are harder to treat. They may require additional surgery to treat the infected portion of the spine.

Nerve Damage

Any surgery that is done near the spinal canal can potentially cause injury to the spinal cord or spinal nerves. Injury can occur from bumping or cutting the nerve tissue with a surgical instrument, from swelling around the nerve, or from the formation of scar tissue. An injury to the spinal cord or spinal nerves can cause muscle weakness and a loss of sensation to the areas supplied by the nerve.

Segmental Instability

Laminectomy surgery can cause the spinal segment to loosen, making it unstable. Each spinal segment includes two vertebrae separated by an intervertebral disc, the nerves that leave the spinal cord at that level, and the small facet joints that link each level of the spinal column.

The facet joints on the back of the spine normally give enough stability, even when the lamina is taken off. This is why surgeons prefer not to remove the facet joints. But these joints may have to be removed if they are enlarged with arthritis or are pushing on the spinal nerves, as explained earlier. When the facet joints must be removed, additional surgery (a fusion) may be needed to fix the loose segment.

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

Ongoing Pain

Many patients get nearly complete relief of symptoms from the lumbar laminectomy procedure. As with any surgery, however, you should expect some pain afterward. If the pain continues or becomes unbearable, talk to your surgeon about treatments that can help control your pain.

After Surgery

What happens after surgery?

Patients are usually able to get out of bed within a few hours after surgery. However, you will be instructed to move your back only carefully and comfortably. Patients are able to return home when their medical condition is stable.

Most patients leave the hospital the day after surgery. They are safe to drive within a week or two. People generally get back to light work by four weeks. Heavier work and sports should wait two to three months. Workers whose jobs involve strenuous manual labor may be counseled to consider different work.

Outpatient physical therapy usually starts four to six weeks after surgery.

Rehabilitation

What should I expect as I recover?

Many surgeons prescribe outpatient physical therapy within six weeks after surgery. Physical therapy after lumbar laminectomy is generally only needed for a total of four to six weeks. You should expect full recovery to take up to four months.

At first, treatments help control pain and inflammation. Ice and electrical stimulation treatments are commonly used to help with these goals. Your therapist may also use massage and other hands-on techniques to ease muscle spasm and pain.

Active treatments are added slowly. These include exercises for improving heart and lung function. Walking and swimming are ideal cardiovascular exercises after lumbar laminectomy surgery. Therapists also teach patients specific exercises to help tone and control the muscles that stabilize the low back.

Your therapist works with you on how to move and do activities. This form of treatment, called body mechanics, is used to help you develop new movement habits. This training helps you keep your back in safe positions as you go about your work and daily activities. At first, this may be as simple as helping you learn how to move safely and easily in and out of bed, how to get dressed and undressed, and how to do some of your routine activities. Then you learn how to keep your back safe while you lift and carry items and as you begin more challenging activities.

As your condition improves, the therapist tailors your program to help prepare you to go back to work. Some patients are not able to go back to a previous job that requires strenuous tasks. Your therapist may suggest changes in job tasks that enable you to go back to your previous job. Your therapist can also suggest alternate forms of work. You’ll learn to do your tasks in ways that keep your back safe and free of extra strain.

Before your therapy sessions end, your therapist will teach you a number of ways to avoid future problems.

A Patient’s Guide to Low Back Pain

Introduction

Low back pain is one of the main reasons Americans visit their doctor. For adults over 40, it ranks third as a cause for doctor visits, after heart disease and arthritis.

Eighty percent of people will have low back pain at some point in their lives. And nearly everyone who has low back pain once will have it again.

Very few people who feel pain in their low back have a serious medical problem. Ninety percent of people who experience low back pain for the first time get better in two to six weeks. Only rarely do people with low back pain develop chronic back problems.

With these facts in mind, you can be assured that back pain is common, that it usually only causes problems for a short period of time, and that you can take steps to ease symptoms and prevent future problems.

This guide will help you understand

• which parts make up the spine and low back
• what causes low back pain, and what the most common symptoms are
• what tests your doctor may run
• how to manage your pain and prevent future problems

Anatomy

Which parts make up the lumbar spine, and how do they work?

The human spine is made up of 24 spinal bones, called vertebrae Vertebrae are stacked on top of one another to create the spinal column. The spinal column gives the body its form. It is the body’s main upright support.

From the side, the spine forms three curves. The neck, called the cervical spine, curves slightly inward. The mid back, or thoracic spine curves outward. The outward curve of the thoracic spine is called kyphosis. The low back, also called the lumbar spine, curves slightly inward. An inward curve of the spine is called lordosis.

The lumbar spine is made up of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. The lowest vertebra of the lumbar spine, L5, connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the two pelvic bones. Some people have an extra, or sixth, lumbar vertebra. This condition doesn’t usually cause any particular problems.

Each vertebra is formed by a round block of bone, called a vertebral body. The lumbar vertebral bodies are taller and bulkier compared to the rest of the spine. This is partly because the low back has to withstand pressure from body weight and from daily actions like lifting, carrying, and twisting. Also, large and powerful muscles attaching on or near the lumbar spine place extra force on the lumbar vertebral bodies.

A bony ring attaches to the back of each vertebral body. When the vertebrae are stacked on top of each other, these rings form a hollow tube. This bony tube surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

The spinal cord extends down to the L2 vertebra. Below this level, the spinal canal encloses a bundle of nerves that goes to the lower limbs and pelvic organs.

The Latin term for this bundle of nerves is cauda equina, meaning horse’s tail.

As the spinal cord travels from the brain down through the spine, it sends out nerves on the sides of each vertebra called nerve roots. These nerve roots join together to form the nerves that travel throughout the body and form the body’s electrical system. The nerve roots that come out of the lumbar spine form the nerves that go to the lower limbs and pelvis. The thoracic spine nerves go to the abdomen and chest. The nerves coming out of the cervical spine go to the neck, shoulders, arms, and hands.

It is sometimes easier to understand what happens in the spine by looking at a spinal segment. A spinal segment includes two vertebrae separated by an intervertebral disc, the nerves that leave the spinal cord at that level, and the small facet joints that link each level of the spinal column.

The intervertebral disc normally works like a shock absorber. It protects the spine against the daily pull of gravity. It also protects the spine during heavy activities that put strong force on the spine, such as jumping, running, and lifting.

An intervertebral disc is made up of two parts. The center, called the nucleus, is spongy. It provides most of the disc’s ability to absorb shock. The nucleus is held in place by the annulus, a series of strong ligament rings surrounding it. Ligaments are strong connective tissues that attach bones to other bones.

Between the vertebrae of each spinal segment are two facet joints. The facet joints are located on the back of the spinal column. There are two facet joints between each pair of vertebrae, one on each side of the spine. A facet joint is made of small, bony knobs that line up along the back of the spine. Where these knobs meet, they form a joint that connects the two vertebrae. The alignment of the facet joints of the lumbar spine allows freedom of movement as you bend forward and back.

The surfaces of the facet joints are covered by articular cartilage. Articular cartilage is a smooth, rubbery material that covers the ends of most joints. It allows the bone ends to move against each other smoothly, without pain.

Two spinal nerves exit the sides of each spinal segment, one on the left and one on the right. As the nerves leave the spinal cord, they pass through a small bony tunnel on each side of the vertebra, called a neural foramen. (The term used to describe more than one opening is neural foramina.)

The lumbar spine is supported by ligaments and muscles. The ligaments are arranged in various layers and run in multiple directions. Thick ligaments connect the bones of the lumbar spine to the sacrum (the bone below L5) and pelvis.

The muscles of the low back are also arranged in layers. Those closest to the surface are covered by a thick tissue called fascia.

The middle layer, called the erector spinae, has strap-shaped muscles that run up and down over the lower ribs, chest, and low back. They blend in the lumbar spine to form a thick tendon that binds the bones of the low back, pelvis, and sacrum.

The deepest layer of muscles connects along the back surface of the spine bones. The muscles also connect the low back, pelvis, and sacrum. These deepest muscles coordinate their actions with the muscles of the abdomen to help hold the spine steady during activity.

Causes

Why do I have low back pain?

There are many causes of low back pain. Doctors are not always able to pinpoint the source of a patient’s pain. But your doctor will make every effort to ensure that your symptoms are not from a serious medical cause, such as cancer or a spinal infection.

The vast majority of back problems are a result of wear and tear on the parts of the spine over many years. This process is called degeneration. Over time, the normal process of aging can result in degenerative changes in all parts of the spine.

Injuries to the spine, such as a fracture or injury to the disc, can make the changes happen even faster. There is strong evidence that cigarette smoking also speeds up degeneration of the spine. Scientists have found links among family members, showing that genetics plays a role in how fast these changes occur.

Degeneration

The intervertebral disc changes over time. At first, the disc is spongy and firm. The nucleus in the center of the disc contains a great deal of water. This gives the disc its ability to absorb shock and protect the spine from heavy and repeated forces.

The first change that occurs is that the annulus around the nucleus weakens and begins to develop small cracks and tears. The body tries to heal the cracks with scar tissue. But scar tissue is not as strong as the tissue it replaces. The torn annulus can be a source of pain for two reasons. First, there are pain sensors in the outer rim of the annulus. They signal a painful response when the tear reaches the outer edge of the annulus. Second, like injuries to other tissues in the body, a tear in the annulus can cause pain due to inflammation.

With time, the disc begins to lose water, causing it to lose some of its fullness and height. As a result, the vertebrae begin to move closer together.

As the disc continues to degenerate, the space between the vertebrae shrinks. This compresses the facet joints along the back of the spinal column. As these joints are forced together, extra pressure builds on the articular cartilage on the surface of the facet joints. This extra pressure can damage the facet joints. Over time, this may lead to arthritis in the facet joints.

These degenerative changes in the disc, facet joints, and ligaments cause the spinal segment to become loose and unstable. The extra movement causes even more wear and tear on the spine. As a result, more and larger tears occur in the annulus.

The nucleus may push through the torn annulus and into the spinal canal. This is called a herniated or ruptured disc. The disc material that squeezes out can press against the spinal nerves. The disc also emits enzymes and chemicals that produce inflammation. The combination of pressure on the nerves and inflammation caused by the chemicals released from the disc cause pain.

View animation of degeneration

As the degeneration continues, bone spurs develop around the facet joints and around the disc. No one knows exactly why these bone spurs develop. Most doctors think that bone spurs are the body’s attempt to stop the extra motion between the spinal segment. These bone spurs can cause problems by pressing on the nerves of the spine where they pass through the neural foramina. This pressure around the irritated nerve roots can cause pain, numbness, and weakness in the low back, buttocks, and lower limbs and feet.

A collapsed spinal segment eventually becomes stiff and immobile. Thickened ligaments and facet joints, scarred and dried disc tissue, and protruding bone spurs prevent normal movement. Typically, a stiff joint doesn’t cause as much pain as one that slides around too much. So this stage of degeneration may actually lead to pain relief for some people.

Mechanical and Neurogenic Pain

To best understand the cause of your pain, spine specialists sometimes divide low back pain into two categories:

• mechanical pain
• neurogenic pain

Mechanical Pain

Mechanical back pain is caused by wear and tear in the parts of the lumbar spine. This type of pain is similar in nature to a machine that begins to wear out. Mechanical pain usually starts from degenerative changes in the disc. As the disc begins to collapse and the space between the vertebrae narrows, the facet joints may become inflamed. Mechanical pain typically gets worse after activity due to strain on the moving parts of the spine. Mechanical pain is usually felt in the back, but it may spread into the buttocks, hips, and thighs. The pain rarely goes down past the knee. Mechanical back pain usually doesn’t cause weakness or numbness in the leg or foot, because the problem is not from pressure on the spinal nerves.

Neurogenic Pain

Neurogenic pain means pain from nerve injury. Neurogenic pain occurs when spinal nerves are inflamed, squeezed, or pinched. This can happen when a disc herniates or when a nerve gets pinched where it leaves the spine. Recently it has also become known that when a disc ruptures, chemicals are released that inflame the nerves even if there is no pressure directly on the nerve. Neurogenic symptoms concern doctors more than mechanical pain because they can signal damage to the nerves and lead to weakness or numbness in the lower extremities.

The nerve pressure causes symptoms in the areas where the nerve travels, rather than in the low back. This happens because pressure on the spinal nerve affects structures away from the spine, such as the muscles. As a result, a person’s back may not hurt, yet the person feels pain, numbness, or weakness in the leg or foot. This indicates there’s a problem with the body’s electrical wiring. The pressure on the nerve affects how the body functions. Muscles weaken. Reflexes slow. Sensations of pins, needles, and numbness may be felt where the nerve travels.

Spine Conditions

The effects of spine degeneration or back injury can lead to specific spine conditions. These include

• annular tears
• internal disc disruption
• herniated disc
• facet joint arthritis
• segmental instability
• spinal stenosis
• foraminal stenosis

Annular Tears

Our intervertebral discs change with age, much like our hair turns gray. Perhaps the earliest stage of degeneration occurs due to tears that occur in the annulus. These tears can result from wear and tear over a period of time. They can also be the result of a sudden injury to the disc due to a twist or increased strain on the disc that overpowers the strength of the annulus. These annular tears may cause pain in the back until they heal with scar tissue.

View animation of annular tearing

Related Document: A Patient’s Guide to Lumbar Degenerative Disc Disease

Internal Disc Disruption

Multiple annular tears can lead to a disc that becomes weak. The disc starts to degenerate and collapse. The vertebrae begin to compress together. The collapsing disc can be the source of pain because it has lost the ability to be a shock absorber between the vertebrae. This condition is sometimes referred to as internal disc disruption. This type of problem causes primarily mechanical back pain due to inflammation of the disc and surrounding structures.

Herniated Disc

A disc that has been weakened may rupture or herniate. If the annulus ruptures, or tears, the material in the nucleus can squeeze out of the disc, or herniate. A disc herniation usually causes compressive problems if the disc presses against a spinal nerve. The chemicals released by the disc may also inflame the nerve root, causing pain in the area where the nerve travels down the leg. This type of pain is referred to as sciatica.

Even a normal disc can rupture. Heavy, repetitive bending, twisting, and lifting can place too much pressure on the disc, causing the annulus to tear and the nucleus to rupture into the spinal canal.

Related Document: A Patient’s Guide to Lumbar Disc Herniation

Facet Joint Arthritis

The facet joints along the back of the spinal column link the vertebrae together. They are not meant to bear much weight. However, if a disc loses its height, the vertebra above the disc begins to compress toward the one below. This causes the facet joints to press together. Articular cartilage covers the surfaces where these joints meet. Like other joints in the body that are covered with articular cartilage, the facet joints can develop osteoarthritis as the articular cartilage wears away over time. Extra pressure on the facet joints, such as that from a collapsing disc, can speed the degeneration in the facet joints. The swelling and inflammation from an arthritic facet joint can be a source of low back pain.

Related Document: A Patient’s Guide to Lumbar Facet Joint Arthritis

Segmental Instability

Segmental instability means that the vertebral bones within a spinal segment move more than they should. In the lumbar spine, this can develop if the disc has degenerated. Usually the supporting ligaments around the vertebrae have also been stretched over time.

Segmental instability also includes conditions in which a vertebral body begins to slip over the one below it. When a vertebral body slips too far forward, the condition is called spondylolisthesis. Whatever the cause, this extra movement in the bones of the spine can create problems. It can lead to mechanical pain simply because the structures of the spine move around too much and become inflamed and painful. The extra movement can also cause neurogenic symptoms if the spinal nerves are squeezed as a result of the segmental instability.

Related Document: A Patient’s Guide to Lumbar Spondylolisthesis

Spinal Stenosis

Stenosis means closing in. Spinal stenosis refers to a condition in which the tissues inside the spinal canal are closed in, or compressed. The spinal cord ends at L2. Below this level, the spinal canal contains only spinal nerves that travel to the pelvis and legs. When stenosis narrows the spinal canal, the spinal nerves are squeezed inside the canal.

The pressure from the condition can cause problems in the way the nerves work. The resulting problems include pain and numbness in the buttocks and legs and weakness in the muscles supplied by the nerves. Because these nerves travel to the bladder and rectum, weakness in the these muscles can cause problems with control of the bladder and bowels.

Related Document: A Patient’s Guide to Lumbar Spinal Stenosis

Foraminal Stenosis

Spinal nerves exit the spinal canal between the vertebrae in a tunnel called the neural foramen. Anything that causes this tunnel to become smaller can squeeze the spinal nerve where it passes through the tunnel. This condition is called foraminal stenosis, meaning the foramen is narrowed. As the disc collapses and loses height, the vertebral body above begins to collapse toward the one below. The opening around the nerve root narrows, squeezing the nerve. Arthritis of the facet joints causes bone spurs to form and point into the foramen, causing further nerve compression and irritation. Foraminal stenosis can cause a combination of mechanical pain and neurogenic pain from the irritated nerve root.

Related Document: A Patient’s Guide to Lumbar Disc Herniation

Symptoms

What are some of the symptoms of low back problems?

Symptoms from low back problems vary. They depend on a person’s condition and which structures are affected. Some of the more common symptoms of low back problems are

• low back pain
• pain spreading into the buttocks and thighs
• pain radiating from the buttock to the foot
• back stiffness and reduced range of motion
• muscle weakness in the hip, thigh, leg, or foot
• sensory changes (numbness, prickling, or tingling) in the leg, foot, or toes

Rarely, symptoms involve changes in bowel or bladder function. A large disc herniation that pushes straight back into the spinal canal can put pressure on the nerves that go to the bowels and bladder. The pressure may cause symptoms of low back pain, pain running down the back of both legs, and numbness or tingling between the legs in the area you would contact if you were seated on a saddle. The pressure on the nerves can cause a loss of control in the bowels or bladder.

This is an emergency.

If the pressure isn’t relieved, it can lead to permanent paralysis of the bowels and bladder. This condition is called cauda equina syndrome. Doctors recommend immediate surgery to remove pressure from the nerves.

Diagnosis

How will my doctor find out what’s causing my problem?

The diagnosis of low back problems begins with a thorough history of your condition. You might be asked to fill out a questionnaire describing your back problems. Your doctor will ask you questions to find out when you first started having problems, what makes your symptoms worse or better, and how the symptoms affect your daily activity. Your answers will help guide the physical examination.

Your doctor will then physically examine the muscles and joints of your low back. It is important that your doctor see how your back is aligned, how it moves, and exactly where it hurts.

Your doctor may do some simple tests to check the function of the nerves. These tests are used to measure the strength in your lower limbs, check your reflexes, and determine whether you have numbness in your legs or feet.

The information from your medical history and physical examination will help your doctor decide which further tests to run. The tests give different types of information.

Radiological Imaging

Radiological imaging tests help your doctor see the anatomy of your spine. There are several kinds of imaging tests that are commonly used.

X-rays

X-rays show problems with bones, such as infection, bone tumors, or fractures. X-rays of the spine also can give your doctor information about how much degeneration has occurred in the spine, such as the amount of space in the neural foramina and between the discs. X-rays are usually the first test ordered before any of the more specialized tests.

Flexion and Extension X-rays

Special X-rays called flexion and extension X-rays may help to determine if there is instability between vertebrae. These X-rays are taken from the side as you lean as far forward and then as far backward as you can. Comparing the two X-rays allows the doctor to see how much motion occurs between each spinal segment.

MRI Scans

The magnetic resonance imaging (MRI) scan uses magnetic waves to create pictures of the lumbar spine in slices. The MRI scan shows the lumbar spine bones as well as the soft tissue structures such as the discs, joints, and nerves. MRI scans are painless and don’t require needles or dye. The MRI scan has become the most common test to look at the lumbar spine after X-rays have been taken.

CT Scans

The computed tomography (CT) scan is a special type of X-ray that lets doctors see slices of bone tissue. The machine uses a computer and X-rays to create these slices. It is used primarily when problems are suspected in the bones.

Myelogram

The myelogram is a special kind of X-ray test where a special dye is injected into the spinal sac. The dye shows up on an X-ray. It helps a doctor see if there is a herniated disc, pressure on the spinal cord or spinal nerves, or a spinal tumor. Before the CT scan and the MRI scan were developed, the myelogram was the only test that surgeons had to look for a herniated disc. The myelogram is still used today but not nearly as often. The myelogram is usually combined with CT scan to give more detail.

Discogram

The discogram is another specialized X-ray test. A discogram has two parts. First, a needle is inserted into the problem disc, and saline is injected into the disc to create pressure inside the disc. If this reproduces your pain, then it suggests that the disc is the source of your pain. During the second part of the test, dye is injected into the disc. The dye can be seen on X-ray. Using both regular X-rays and CT scan images, the dye outlines the inside of the disc. This can show abnormalities of the nucleus such as annular tears and ruptures of the disc.

Bone Scan

A bone scan is a special test where radioactive tracers are injected into your blood stream. The tracers then show up on special X-rays of your back. The tracers build up in areas where bone is undergoing a rapid repair process, such as a healing fracture or the area surrounding an infection or tumor. Usually the bone scan is used to locate the problem. Other tests such as the CT scan or MRI scan are then used to look at the area in detail.

Other Tests

Your doctor may also ask you to do other tests.

Electromyogram

An electromyogram (EMG) is a special test used to determine if there are problems with any of the nerves going to the lower limbs. EMGs are usually done to determine whether the nerve roots have been pinched by a herniated disc. During the test, small needles are placed into certain muscles that are supplied by each nerve root. If there has been a change in the function of the nerve, the muscle will send off different types of electrical signals. The EMG test reads these signals and can help determine which nerve root is involved.

Laboratory Tests

Not all causes of low back pain are from degenerative conditions. Doctors use blood tests to identify other conditions, such as arthritis or infection. Low back pain can be caused by problems that do not involve the spine, such as stomach ulcers, kidney problems, and aneurysms of the aorta. Other tests may be needed to rule out problems that do not involve the spine.

Treatment

What can be done to relieve my symptoms?

Ninety percent of people who experience low back pain for the first time get better in two to six weeks without any treatment at all. Patients often do best when encouraged to stay active and to get back to normal activities as soon as possible, even if there is still some pain. The pain may not go away completely. One goal of treatment is to help you find ways to control the pain and allow you to continue to do your normal activities.

Nonsurgical Treatment

Whenever possible, doctors prefer to use treatments other than surgery. The first goal of these nonsurgical treatments is to ease your pain and other symptoms.

Bed Rest

In cases of severe pain, doctors may suggest a short period of bed rest, usually no more than two days. Lying on your back can take pressure off sore discs and nerves. Most doctors advise against strict bed rest and prefer that patients do ordinary activities using pain to gauge how much is too much.

Back Brace

A back support belt is sometimes recommended when back pain first strikes. It can help provide support and lower the pressure inside a problem disc. Patients are encouraged to gradually discontinue wearing the support belt over a period of two to four days. Otherwise, back muscles begin to rely on the belt and start to shrink (atrophy).

Medications

Many different types of medications are typically prescribed to help gain control of the symptoms of low back pain. There is no medication that will cure low back pain. Medications are prescribed to help with sleep disturbances and to help control pain, inflammation, and muscle spasm.

Physical Therapy and Exercise

In addition to other nonsurgical treatments, doctors often ask their patients to work with a physical therapist. Therapy treatments focus on relieving pain, improving back movement, and fostering healthy posture. A therapist can design a rehabilitation program to address a particular condition and to help the patient prevent future problems. There is a great deal of scientific proof that exercise and increased overall fitness reduce the risk of developing back pain and can improve the symptoms of back pain once it begins.

Injections

Spinal injections are used for both treatment and diagnostic purposes. There are several different types of spinal injections that your doctor may suggest. These injections usually use a mixture of an anesthetic and some type of cortisone preparation. The anesthetic is a medication that numbs the area where it is injected. If the injection takes away your pain immediately, this gives your doctor important information suggesting that the injected area is indeed the source of your pain. The cortisone decreases inflammation and can reduce the pain from an inflamed nerve or joint for a prolonged period of time.

Some injections are more difficult to perform and require the use of a fluoroscope. A fluoroscope is a special type of X-ray that allows the doctor to see an X-ray picture continuously on a TV screen. The fluoroscope is used to guide the needle into the correct place before the injection is given.

• Epidural Steroid Injection (ESI): Back pain from inflamed nerve roots and facet joints may benefit from an epidural steroid injection (ESI). In an ESI, the medication mixture is injected into the epidural space around the nerve roots. Generally, an ESI is given only when other nonoperative treatments aren’t working. ESIs are not always successful in relieving pain. If they do work, they may only provide temporary relief.

• Selective Nerve Root Injection: Another type of injection to place steroid medication around a specific inflamed nerve root is called a selective nerve root injection. The fluoroscope is used to guide a needle directly to the painful spinal nerve root. The nerve root is then bathed with the medication. Some doctors believe this procedure gets more medication to the painful spot. In difficult cases, the selective nerve root injection can also help surgeons decide which nerve root is causing the problem before surgery is planned.

• Facet Joint Injection: When the problem is thought to be in the facet joints, an injection into one or more facet joints can help determine which joints are causing the problem and ease the pain as well. The fluoroscope is used to guide a needle directly into the facet joint. The facet joint is then filled with medication mixture. If the injection immediately eases the pain, it helps confirm that the facet joint is a source of pain. The steroid medication will reduce the inflammation in the joint over a period of days and may reduce or eliminate your back pain.

• Trigger Point Injections: Injections of anesthetic medications mixed with a cortisone medication are sometimes given in the muscles, ligaments, or other soft tissues near the spine. These injections are called trigger point injections. These injections can help relieve back pain and ease muscle spasm and tender points in the back muscles.

Surgery

Only rarely is lumbar spine surgery scheduled right away. Your doctor may suggest immediate surgery if you are losing control of your bowels and bladder or if your muscles are becoming weaker very rapidly.

For other conditions, doctors prefer to try nonsurgical treatments for a minimum of three months before considering surgery. Most people with back pain tend to get better, not worse. Even people who have degenerative spine changes tend to gradually improve with time. Only one to three percent of patients with degenerative lumbar conditions typically require surgery. Surgery may be suggested when severe pain is not improving.

There are many different operations for back pain. The goal of nearly all spine operations is to remove pressure from the nerves of the spine, stop excessive motion between two or more vertebrae, or both. The type of surgery that is best depends on that patient’s conditions and symptoms.

Laminectomy

The lamina is the covering layer of the bony ring of the spinal canal. It forms a roof-like structure over the back of the spinal column. When the nerves in the spinal canal are being squeezed by a herniated disc or from bone spurs pushing into the canal, a laminectomy removes part or all of the lamina to release pressure on the spinal nerves.

Related Document: A Patient’s Guide to Lumbar Laminectomy

Discectomy

When the intervertebral disc has ruptured, the portion that has ruptured into the spinal canal may put pressure on the nerve roots. This may cause pain, weakness, and numbness that radiates into one or both legs. The operation to remove the portion of the disc that is pressing on the nerve roots is called a discectomy. This operation is performed through an incision in the low back immediately over the disc that has ruptured.

Many spine surgeons now perform discectomy procedures that require only small incisions in the low back (minimally invasive). The advantage of these minimally invasive procedures is less damage to the muscles of the back and a quicker recovery. Many surgeons are now performing minimally invasive discectomy as an outpatient procedure.

Related Document: A Patient’s Guide to Lumbar Discectomy

Lumbar Fusion

When there is excessive motion between two or more vertebrae, the excess motion can cause both mechanical pain and irritation of the nerves of the lumbar spine. In this case some type of spinal fusion is usually recommended. The goal of a spinal fusion is to force two or more vertebrae to grow together, or fuse, into one bone. A solid fusion between two vertebrae stops the movement between the two bones. The pain is reduced because the fusion reduces the constant irritation and inflammation of the nerve roots. There are many different types of spinal fusions.

• Posterior Lumbar Fusion: In the past, the traditional operation to perform a fusion of the lumbar spine was to decorticate the back surface of the vertebrae. Decorticate means to remove the hard outside covering of a bone to create a bleeding bone surface. Once this was done, bone graft was taken from the pelvis and laid on top of the decorticated vertebrae. The body tries to heal this area just like it would a fractured bone. The bone graft and the bleeding bone grow together and fuse to create one solid bone. Spinal fusions were not always successful, mainly because the vertebrae failed to fuse together in up to 20 percent of cases. Surgeons began looking for ways to increase the success of fusions. For many years, metal plates and screws have been used to treat fractures of other bones. The more rigid two bones can be held together while the healing phase occurs, the more likely the bones are to heal. Spine surgeons began looking for ways to hold the vertebrae together while the fusion took place.

  Related Document: A Patient’s Guide to Posterior Lumbar Fusion

• Posterior Lumbar Instrumented Fusion: Major advances have been made in recent years in developing metal rods, metal plates, and special screws that are designed to hold the vertebrae together while the fusion takes place. These new techniques of spinal fusion are referred to as instrumented fusions because of the special devices used to secure the vertebrae to be fused. Today the most common type of posterior fusion is performed using special screws called pedicle screws that are inserted into each vertebra and connected to either a metal plate or metal rod along the back of the spine. The vertebrae are still decorticated, and bone graft is still used to stimulate the bones to heal together and fuse into one solid bone.

• Anterior Lumbar Interbody Fusion: A fusion of the lumbar spine can be accomplished in other ways. In some cases, surgeons feel that it is best to perform a fusion from the front of the spine. This is termed an anterior interbody fusion. This type of fusion requires an incision in the side of the abdomen to allow the surgeon to see the front of the spine. The intervertebral disc is removed between two vertebral bodies and bone graft is inserted where the disc was removed. The two vertebral bodies heal together and fuse.Related Document: A Patient’s Guide to Anterior Lumbar Interbody Fusion

• Anterior Lumbar Discectomy and Fusion with Cages: Degeneration of the intervertebral disc allows the vertebrae to move closer together, which narrows the openings (the neural foramina) where the nerve roots leave the spinal canal.Surgeons realized that restoring the normal separation between the vertebrae would open the foramina and take pressure off the nerve roots. Over the last several years, devices called fusion cages have been designed that can be placed between

  
  the vertebrae to hold them apart while the fusion occurs. Enlarging the space between two vertebrae widens the opening of the neural foramina, taking pressure off the spinal nerves that pass through them. The extra space also pulls taut the ligaments inside the spinal canal so they don’t buckle.

  Fusion cages are made of metal, bone, or graphite material. Some of these cages are shaped like cylinders. They are threaded like a screw on the outside and hollow on the inside. Some are rectangular in shape. The main purpose of the cage, regardless of the shape or material, is to hold the two vertebrae apart while the fusion becomes solid.

  Related Document: A Patient’s Guide to Anterior Lumbar Fusion with Cages

• Posterior Lumbar Interbody Fusion: Finally, surgeons may combine the two methods of anterior fusion and posterior fusion. Fusing both the anterior and posterior portions of the spine gives the most solid fusion. Placing intervertebral cages between the two vertebrae also allows the surgeon to restore the disc height and help take pressure off of the nerve roots that exit at that spinal segment. A common method of doing this is called a posterior lumbar interbody fusion, combined with a posterior lumbar instrumented fusion (described earlier).

Related Document: A Patient’s Guide to Posterior Lumbar Interbody Fusion

Rehabilitation

What should I expect after treatment?

Nonsurgical Rehabilitation

For acute back pain, you may be prescribed two to four weeks of physical therapy. You might need to continue therapy for two to four months for chronic back problems. Treatments are designed to ease pain and to improve your mobility, strength, posture, and function. You’ll also learn how to control your symptoms and how to protect your spine for the years ahead.

At first, your therapist may apply various forms of treatment to address your symptoms. These are especially helpful in the early weeks to improve your comfort so you can get back to your normal activities. You’ll be shown ways to position your spine for maximum comfort while you move, recline, or sleep. To help calm pain and muscle spasm, your therapist may apply heat or ice packs, electrical stimulation, and ultrasound.

If you have severe back pain, your therapist may work with you in a pool. Therapy done in water puts less stress on your low back, and the buoyancy allows you to move easier during exercise.

Hands-on treatments such as massage and specialized forms of soft-tissue mobilization may be used. They can help you begin moving with less pain and greater ease. Medical guidelines also include the early use of spinal manipulation, which has shown short-term benefits in people with acute low back pain. Commonly thought of as an adjustment, spinal manipulation helps reset the sensitivity of the spinal nerves and muscles, easing pain and improving mobility. It involves a high-impulse stretch of the spinal joints and is often characterized by the sound of popping as the stretch is done. It doesn’t provide effective long-term help when used routinely for chronic conditions.

You may be tempted to limit your activity because of your back pain. However, as a result of pain and inactivity, your muscles may become weak and deconditioned, and your back won’t function optimally. Therapists use active rehabilitation to prevent the harmful effects of deconditioning. With this active approach, you’ll be shown how to lift and move safely. And you’ll be shown how to strengthen your back muscles. In addition, aerobic exercises are used to improve your general fitness and endurance.

Aerobic exercises may include walking on a treadmill, riding a stationary bike, or swimming. These activities can relieve the stress of low back pain, and they can cause your body to release endorphins into the blood stream. Endorphins are your body’s own natural painkillers.

An active approach to therapy can help you attain better muscle function, so you can get your activities done easier. Active rehabilitation speeds recovery, reducing the possibility that back pain will become a chronic problem. Activity helps you resume normal activity as swiftly as possible. Though you’ll be cautioned about trying to do too much, too quickly, you’ll be guided toward a return to your usual activities. This approach gives you a greater sense of control. You’ll take an active role in learning how to care for your back pain. Treatment sessions focus on reassuring you that getting back to work and other normal activities swiftly won’t cause you harm and can actually help you get better faster.

When needed, you’ll be encouraged to take certain actions to improve your spine health. For example, if you smoke, you’ll be encouraged to get help to quit. Because of the limited blood supply in the tissues of the low back, smoking speeds the degenerative process and impairs healing. If you’re out of shape, you’ll be encouraged to get fit. This strategy makes it less likely that back pain or injury will strike again in the future.

Your therapist will show you how to keep your spine safe during routine activities. You’ll learn about healthy posture and how posture relates to the future health of your spine. And you’ll learn about body mechanics, how the body moves and functions during activity. Your therapist will also teach safe body mechanics to help you protect your low back as you go about your day. This includes the use of safe positions and movements while lifting and carrying, standing and walking, and performing work duties.

As you recover, you will gradually advance in a series of strengthening exercises for the abdominal and low back muscles. Working these core muscles can help you begin moving easier and lessens the chances of future pain and problems.

As the rehabilitation program evolves, you will progress with more challenging exercises. The goal is to safely advance your strength and function.

Your therapist will work closely with your doctor and employer to help you get back on the job as quickly as reasonably possible. You may be required to do lighter duties at first, but as soon as you are able, you’ll begin doing your normal work activities. Your therapist can also do a work assessment to make sure you’ll be safe to do your job. Your therapist may suggest changes that could help you work safely, with less chance of re-injuring your back.

After Surgery

Rehabilitation after surgery is much more complex. Depending on what operation you’ve had, you may leave the hospital shortly after surgery. Some procedures, such as fusion surgery, require that you stay in the hospital for a few days. When you stay in the hospital, a physical therapist may visit you in your hospital room soon after surgery. Physical therapy sessions help you learn to move and begin doing routine activities without putting extra strain on your low back.

During recovery from surgery, you should follow your surgeon’s instructions about wearing a back brace or soft lumbar support belt. You should be cautious about overdoing activities in the first few weeks after surgery.

You may need therapy outside of the hospital. If you had a lumbar fusion, your surgeon may have you wait six weeks to three months before starting therapy. Once you start in therapy, you’ll usually go for one to three months, depending on your progress and the type of surgery you had.

At first, your therapist may use treatments such as heat or ice, electrical stimulation, massage, and ultrasound to help calm pain and muscle spasm. Pool therapy is often helpful after lumbar surgery.

Exercises are used to improve flexibility in your trunk and lower limbs. Strengthening for your abdominal and low back muscles is started. You’ll be shown safe ways to sleep, sit, lift, and carry. And you’ll be given ideas on how to do your work activities safely.

Ideally, you’ll be able to go back to your previous activities. However, you may need to modify your activities to avoid future problems.

When treatment is well under way, regular visits to the therapist’s office will you’re your therapist will continue to be a resource. But you are in charge of doing your exercises as part of an ongoing home program.

A Patient’s Guide to Lumbar Spinal Stenosis

Introduction

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.

This guide will help you understand

• how the problem develops
• how doctors diagnose the condition
• what treatment options are available

Anatomy

What part of the back is involved?

The human spine is made up of 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column. The spinal column gives the body its form. It is the body’s main upright support.

The back portion of the spinal column forms a bony ring. When the vertebrae are stacked on top of each other, these bony rings create a hollow tube. This bony tube, called the spinal canal, surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

The spinal cord only extends to the second lumbar (low back) vertebra. Below this level, the spinal canal encloses a bundle of nerves that go to the lower limbs and pelvic organs. The Latin term for this bundle of nerves is cauda equina, meaning horse’s tail.

An intervertebral disc fits between each vertebral body and provides a space between the spine bones. The disc normally works like a shock absorber. It protects the spine against the daily pull of gravity. It also protects the spine during heavy activities that put strong force on the spine, such as jumping, running, and lifting.

An intervertebral disc is made up of two parts. The center, called the nucleus, is spongy. It provides most of the ability to absorb shock. The nucleus is held in place by the annulus, a series of strong ligament rings surrounding it. Ligaments are strong connective tissues that attach bones to other bones.

Related Document: A Patient’s Guide to Lumbar Spine Anatomy

Causes

Why do I have this problem?

In the lumbar spine, the spinal canal usually has more than enough room for the spinal nerves. The canal is normally 17 to 18 millimeters around, slightly smaller than a penny. Spinal stenosis develops when the canal shrinks to 12 millimeters or less. When the size drops below 10 millimeters, severe symptoms of lumbar spinal stenosis occur.

There are many reasons why symptoms of spinal stenosis develop. Some of the more common reasons include

• congenital stenosis (being born with a small spinal canal)
• spinal degeneration
• spinal instability
• disc herniation

Congenital stenosis: Some people are born with (congenital) a spinal canal that is narrower than normal. They may not feel problems early in life. However, having a narrow spinal canal puts them at risk for stenosis. Even a minor back injury can cause pressure against the spinal cord. People born with a narrow spinal canal often have problems later in life, because the canal tends to become narrower due to the effects of aging.

Degeneration: Degeneration is the most common cause of spinal stenosis. Wear and tear on the spine from aging and from repeated stresses and strains can cause many problems in the lumbar spine. The intervertebral disc can begin to collapse, and the space between each vertebrae shrinks. Bone spurs may form that stick into the spinal canal and reduce the space available to the spinal nerves. The ligaments that hold the vertebrae together may thicken and also push into the spinal canal. All of these conditions cause the spinal canal to narrow.

View animation of degeneration

Spinal instability: Spinal instability can cause spinal stenosis. Spinal instability means that the bones of the spine move more than they should. Instability in the lumbar spine can develop if the supporting ligaments have been stretched or torn from a severe back injury. People with diseases that loosen their connective tissues may also have spinal instability. Whatever the cause, extra movement in the bones of the spine can lead to spinal stenosis.

Disc herniation: Spinal stenosis can occur when an intervertebral disc in the low back herniates (ruptures). Normally, the shock-absorbing disc is able to handle the downward pressure of gravity and the strain from daily activities. However, if the pressure on the disc is too strong, such as landing from a fall in a sitting position, the nucleus inside the disc may rupture through the outer annulus and squeeze out of the disc. This is called a disc herniation. If an intervertebral disc herniates straight backward, it can press against the nerves in the spinal canal, causing symptoms of spinal stenosis.

Symptoms

What does the spinal stenosis feel like?

Spinal stenosis usually develops slowly over a long period of time. This is because the main cause of spinal stenosis is spinal degeneration in later life. Symptoms rarely develop quickly when degeneration is the source of the problem. A severe injury or a herniated disc may cause symptoms to develop immediately.

Patients with stenosis don’t always feel back pain. Primarily, they have severe pain and weakness in their legs, usually in both legs at the same time. Some people say they feel that their legs are going to give out on them.

Symptoms mainly affect sensation in the lower limbs. Nerve pressure from stenosis can cause a feeling of pins and needles in the skin where the spinal nerves travel. Reflexes become slowed. Some patients report charley horses in their leg muscles. Others report strange sensations like water trickling down their legs.

Symptoms change with the position of the low back. Flexion (bending forward) widens the spinal canal and usually eases symptoms. That’s why people with stenosis tend to get relief when they sit down or curl up to sleep. Activities such as reaching up, standing, and walking require the spine to straighten or even extend (bend back slightly). This position of the low back makes the spinal canal smaller and often worsens symptoms.

Diagnosis

How do doctors diagnose the problem?

Diagnosis begins with a complete history and physical examination. Your doctor will ask questions about your symptoms and how your problem is affecting your daily activities. This will include questions about your pain or if you have feelings of numbness or weakness in your legs.

Your doctor will also want to know whether your symptoms are worse when you’re up standing or walking and if they go away when you sit down. If your pain does not get worse when walking, then you probably don’t have stenosis. There may be some other cause of the painful symptoms.

The doctor does a physical examination to see which back movements cause pain or other symptoms. Your skin sensation, muscle strength, and reflexes are also tested. A wide-based gait (legs far apart) is often observed. Special clinical tests can be done such as the Romberg test, hip extension test, and tests of neuromuscular function.

The Romberg test is a neurologic test for joint proprioception (sense of position). The nerve pathways for this sensation travel up the dorsal columns of the spinal cord. Dorsal means they are located towards the back where stenosis is more likely to occur. The test is done standing with feet together, eyes open, and hands by your sides. You will be asked to close your eyes for one full minute while your doctor observes you. Romberg’s test is positive if you can stand with your eyes open but fall (or start to fall, someone will be there to make sure you don’t fall down) when your eyes are closed. The test is not positive if you start to sway with your eyes closed but don’t lose your balance.

X-rays can show if the problems are from changes in the bones of the spine. The images can show if degeneration has caused the space between the vertebrae to collapse. X-rays may also show any bone spurs sticking into the spinal canal.

The best way to see the effects and extent of lumbar spinal stenosis is with a magnetic resonance imaging (MRI) scan. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. This test gives a clear picture of the spinal canal and whether the nerves inside are being squeezed. This machine creates pictures that look like slices of the area your doctor is interested in. The test does not require dye or a needle.

Computed tomography (a CT scan) may be ordered for those patients who can’t have an MRI for some reason, when the results of the MRI are unclear, or symptoms don’t match the MRI findings. The CT scan is a detailed X-ray that lets your doctor see slices of bone tissue. The image can show any bone spurs that may be sticking into the spinal column and taking up space around the spinal nerves.

When there is a concern about neurologic problems, doctors may recommend electrodiagnostic tests of the nerves that go to the legs and feet. An electromyogram (EMG) checks whether the motor pathway of a nerve is working correctly. Motor impulses travel down the nerve and work to energize muscles.

Doctors may also order a somatosensory evoked potential (SSEP) test to locate more precisely where the spinal nerves are being squeezed. The SSEP is used to measure nerve sensations. These sensory impulses travel up the nerve, informing the body about sensations such as pain, temperature, and touch. The function of a nerve is recorded by an electrode placed over the skin in the area where the nerve travels.

Not all causes of spinal stenosis are from degenerative conditions. Doctors use blood tests to determine whether symptoms are coming from other conditions, such as arthritis or infection.

Treatment

What treatment options are available?

Nonsurgical Treatment

Unless your condition is causing significant problems or is rapidly getting worse, most doctors will begin with nonsurgical treatments. Up to one-half of all patients with mild-to-moderate lumbar spinal stenosis can manage their symptoms with conservative (nonsurgical) care. Neurologic decline and paralysis in this group is rare.

At first, doctors may prescribe ways to immobilize the spine. Keeping the back still for a short time can calm inflammation and pain. This might include one to two days of bed rest. Patients may find that curling up to sleep or lying back with their knees bent and supported gives the greatest relief. These positions flex the spine forward, which widens the spinal canal and can ease symptoms.

A lumbar support belt or corset may be prescribed, though their benefits are controversial. Lumbosacral corsets do not appear to offer any long-term benefits. The support provides symptom relief only while you are wearing it. The support can limit pressure in the discs and prevent extra movement in the spine. But it can also cause the back and abdominal muscles to weaken. Some doctors have their patients wear a rigid brace that holds the spine in a slightly flexed position, widening the spinal canal. Health care providers normally only have patients wear a corset for one to two weeks.

Doctors sometimes prescribe medication for patients with spinal stenosis. Patients may be prescribed anti-inflammatory medication such as nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin. These medications can cause side effects in the kidneys and gastrointestinal tract. Also, because most stenosis patients are elderly, doctors closely monitor patients who are using these medications to avoid complications.

Narcotic drugs, such as codeine or morphine, are generally not prescribed for stenosis patients. They are addictive when used too much or improperly. Muscle relaxants are occasionally used to calm muscles in spasm.

Symptoms of stenosis can lead to mood changes. As a result, doctors sometimes prescribe anti-depressant medication, called tricyclics. Tricyclics help steady peoples’ moods, and some tricyclics even improve sleep by helping the body make an important hormone called serotonin. These medications also seem to calm back pain by affecting the membranes around pain nerves.

Some patients are given an epidural steroid injection (ESI). The spinal cord is covered by a material called dura. The space between the dura and the spinal column is called the epidural space. It is thought that injecting steroid medication into this space fights inflammation around the nerves, the discs, and the facet joints. This can reduce swelling and give the nerves more room inside the spinal canal.

Research shows that a single steroid injection offers only short-term relief. Multiple injections can produce long-term, lasting pain relief. Epidural injections should be given using contrast-enhanced fluoroscopy. Fluoroscopy is an imaging technique used by the surgeon to guide the needle to the right spot during the procedure. This type of imaging improves the accuracy of medication delivery.

Patients often work with a physical therapist. By evaluating your condition, your therapist can assign positions and exercises to ease your symptoms. Your therapist may suggest using traction. Traction is a common treatment for stenosis. It gently stretches the low back, taking pressure off the spinal nerves. Your therapist may also suggest strengthening and aerobic exercises. Strengthening exercises focus on improving the strength and control of the back and abdominal muscles. Aerobic exercises are used to improve heart and lung health and increase endurance in the spinal muscles. Stationary biking offers a good aerobic treatment and keeps the spine bent slightly forward, a position affording relief to many patients with lumbar stenosis.

Surgery

If the symptoms you feel are mild and there is no danger they’ll get worse, surgery is not usually recommended. Some patients may benefit from the use of a device called the X-STOP®. The X-STOP® is a metal implant made of titanium. The implant is inserted through a small incision in the skin of your back. It is designed to fit between the spinous processes of the vertebrae in your lower back. It stays in place permanently without attaching to the bone or ligaments in your back.

There are several advantages of the X-STOP®. It can be inserted using local anesthesia on an outpatient basis. A small incision is made so the procedure is minimally invasive and no bone or soft tissue is removed. The implant is not close to nerves or the spinal cord. With the implant in place, you won’t have to bend forward to relieve your symptoms. The X-STOP® keeps the space between your spinous processes open. With the implant in place, you stand upright without pinching the nerves in your back.

But for anyone with severe symptoms of lumbar spinal stenosis, surgery may be needed. When there are signs that pressure is building on the spinal nerves, decompressive surgery may be required, sometimes right away. Decompression means that bone and/or soft tissue are removed from around the spinal nerves to take the pressure off. The signs doctors watch for when reaching this decision include weakening in the leg muscles, pain that won’t ease up, and problems with the bowels or bladder.

Pressure on the spinal nerves can cause a loss of control in the bowels or bladder. This is an emergency. If the pressure isn’t relieved, it can lead to permanent paralysis of the bowels and bladder. Surgery is recommended to remove pressure from the nerves.

The main surgical procedure used to treat spinal stenosis is lumbar laminectomy. Some patients also require fusion surgery immediately after the laminectomy procedure if spinal instability is present.

Lumbar Laminectomy

The lamina is the covering layer of the bony ring of the spinal column. It forms a roof-like structure over the back of the spinal canal. When the nerves in the spinal canal are being squeezed by a herniated disc or bone spurs, a lumbar laminectomy removes the entire lamina to release pressure on the spinal nerves. This is the primary type of surgery used for lumbar spinal stenosis.

Related Document: A Patient’s Guide to Lumbar Laminectomy

Posterior Lumbar Fusion

A posterior lumbar fusion may be needed after a surgeon performs a lumbar laminectomy. The fusion procedure is recommended when a spinal segment has become loose or unstable.

A fusion surgery joins two or more bones into one solid bone. This keeps the bones and joints from moving. In this procedure, the surgeon lays small grafts of bone over the back of the spine. Most surgeons also apply metal plates and screws to prevent the two vertebrae from moving.

This protects the graft so it can heal better and faster.

Related Document: A Patient’s Guide to Posterior Lumbar Fusion

Rehabilitation

What should I expect as I recover?

Nonsurgical Rehabilitation

Even if you don’t need surgery, your doctor may recommend that you work with a physical or occupational therapist. Patients are normally seen a few times each week for one to two months. In severe cases, patients may need a few additional weeks of care.

Your therapist creates a program to help you regain back movement, strength, endurance, and function. Treatments for lumbar spinal stenosis often include lumbar traction, described earlier. Hands-on treatments such as massage and specialized forms of soft-tissue mobilization may be used initially. They are used to help you begin moving with less pain and greater ease. Therapists also guide patients in a program of exercise designed to widen the spinal canal and take pressure off the spinal nerves.

It is important to improve the strength and coordination in the abdominal and low back muscles. Your therapist can also evaluate your workstation or the way you use your body when you do your activities and suggest changes to avoid further problems.

After Surgery

After surgery, surgeons may have their patients work with a physical or occupational therapist. Patients who’ve had fusion surgery normally need to wait two to three months before beginning a rehabilitation program. They will probably need to attend therapy sessions for six to eight weeks and should expect full recovery to take up to six months.

During therapy after surgery, the therapist may use treatments such as heat or ice, electrical stimulation, and massage to help calm pain and muscle spasm. Then patients begin learning how to move safely with the least strain on their healing back.

As the rehabilitation program evolves, patients do more challenging exercises. The goal is to safely advance strength and function. As the therapy sessions come to an end, therapists help patients get back to the activities they enjoy.

Ideally, patients are able to resume normal activities. Patients may need guidance on which activities are safe or how to change the way they go about certain activities.

When treatment is well under way, regular visits to the therapist’s office will end. The therapist will continue to be a resource. But patients are in charge of doing their exercises as part of an ongoing home program.