What Is Lumbar Spinal Stenosis?

Lumbar spinal stenosis is a common cause of low back, buttock, and leg pain in adults 50 and older. This condition is caused by nerve compression and symptoms may include tingling, numbness, and weakness. Leg symptoms are sometimes described as sciatica or lumbar radiculopathy.

Lumbar Spinal Stenosis Causes

Most people who have spinal stenosis in their low back have developed it during their lives—this is known as acquired spinal stenosis. A few people are born with lumbar spinal stenosis—also called primary or congenital spinal stenosis.

Causes of or contributing factors to acquired lumbar spinal stenosis include:

Degenerative Disc Disease

Degenerative disc disease is not really a disease but a condition that develops from wear and tear, injury, and aging. The process of growing older causes gradual changes in the spine at the cellular level. Over time, discs may gradually lose their ability to retain water causing a disc to flatten and lose its normal shape and resiliency—changes that affect its structure and strength.

Such changes increase the risk for a disc to bulge or herniate. A disc herniation occurs when the disc’s soft jellylike core (nucleus pulposus) spills outside the disc’s wall (annulus fibrosus), causing swelling and acute pain.

Each intervertebral disc separates adjacent vertebral bodies from one another. The space the disc creates between the bones permits nerves to exit the spinal column on each side. Loss of disc height can reduce the size of that space, narrow the neural foramen (nerve passageways) and compress the nerves. A disc that bulges or herniates also can compress a nearby nerve root and/or push into the spinal canal and encroach on the nerves collected within the spine, the so-called cauda equina.

Spondylosis

Another degenerative disorder is spinal osteoarthritis, also called spondylosis. This type of arthritis may trigger development of bone spurs (osteophytes) on bony edges of the vertebral bodies and where bone meets, such as the facet joints. Bone spurs may grow or push into the lumbar spine’s nerve roots and/or spinal canal.

Spondylolisthesis

Another cause of lumbar spinal stenosis is spondylolisthesis. This condition develops when a vertebral body in the low back slips forward (or backward, called retrolisthesis) on the neighboring vertebrae, narrowing the spinal canal, leading to compression of the spinal nerve roots.

Other Causes

Less common causes include lumbar degenerative scoliosis (adult onset scoliosis), tumor (benign or cancerous), spinal infection, and Paget’s disease.

Lumbar Spinal Stenosis Symptoms

The symptoms of lumbar spinal stenosis vary, although pain in the low back, buttocks, and back of the thighs that worsens when walking and standing and is relieved with sitting are most common.

Some people experience no symptoms at all—narrowing in the spinal canal and nerve passageways doesn’t necessarily mean symptoms will occur.

Common symptoms of lumbar spinal stenosis include low back pain and lumbar radiculopathy. Widely known as sciatica, lumbar radiculopathy is pain, numbness, weakness, and/or tingling that radiates from the low back down into the buttocks, legs, and calves. You may experience pain in both legs, though one leg can be worse than the other.

Many people with lumbar spinal stenosis experience symptoms only when they are standing or active. You may not be able to walk a great distance, such as several blocks, before leg pain starts. Sitting or resting only temporarily relieves pain and symptoms, which return after standing and walking.

Severe cases of lumbar spinal stenosis may result in cauda equina syndrome. This develops when the cauda equina is compressed, which is a rare occurrence. Symptoms of cauda equina syndrome may include bladder or bowel incontinence.

If you're having problems controlling your bladder or bowel, you should seek immediate medical attention.

Lumbar Spinal Stenosis Diagnosis

Your doctor reviews your medical history and talks with you about your pain and symptoms. Next, he or she performs a physical and neurological exam and compares the findings to your pain and symptoms. An X-ray and/or other diagnostic studies (MRI, CT scan, or an EMG) may be ordered to evaluate your anatomical structures in your low back, including the spinal canal and neural foramen. Imaging tests are essential to identify the cause of spinal stenosis (eg, spondylosis, disc herniation) and confirm your diagnosis.

Lumbar Spinal Stenosis Treatment Options

During your conversation with your doctor, he will ask about treatments you’ve already tried to help relieve and manage your low back pain and spinal stenosis symptoms. Previous therapies may have been provided by another doctor or practitioner (eg, pain management specialist, physiatrist). Insight into treatments that helped and those that were ineffective is important to developing your treatment plan.

It’s important to know that lumbar spinal stenosis is rarely an urgent surgical situation; in fact, many patients do not need spine surgery. Rather, nonsurgical treatments often effectively manage pain and symptoms related to spinal disorders that cause spinal canal and/or nerve compression. Some therapies are combined and may include a treatment that was previously ineffective.

Nonoperative therapies may include:

• Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs)

• Massage

• Heat

• Acupuncture

• Prescription anti-inflammatory, analgesic, topical drug

• Spinal injections

• Physical therapy

Spine surgery may be considered or recommended if nonoperative therapies are ineffective, your symptoms progressively or worsen, you have significant weakness or pain or the inability to walk becomes intractable or difficult to manage.

Surgery for Lumbar Spinal Stenosis

When surgery is needed, the primary goals of surgery for lumbar spinal stenosis are to:

• Decompress the nerves that are compressed (ie, make more room for the nerves). This can be achieved either by opening up the back of the spinal canal, also known as a laminectomy, or by restoring the height of a collapsed disc by placing a device into the disc to lift it up. In some cases both techniques are used.

• Restore stability to the spine. This is commonly the case when the patient has a spondylolisthesis or when the surgeon needs to remove substantial bone from the spine to decompress the nerves. The most common way that stability is restored is by performing a fusion where bone and implants are inserted into the spine.

• A number of traditional or open techniques exist to achieve these goals of decompression and stabilization. More recently, minimally invasive options have been developed that can achieve these same aims with reduced blood loss, risk of infection and recovery time.