Spinal stenosis

Spinal stenosis occurs when there is an abnormal narrowing of the spinal column. There are numerous possible causes, but essentially they lead to pressure on the spinal cord and/or the nerves that branch out from it.

What is the spinal column?

The spinal column is made up of 24 articulated and 10 fused bones (vertebrae). The vertebrae are linked by discs that act as shock absorbers for the spine.

The spinal column plays a vital role in the support of the upper body. It allows us to keep an upright posture, bend and twist. It also protects the spinal cord.

Within the spinal column is the spinal canal. Spinal stenosis occurs when there is an abnormal narrowing of this canal. The spine can narrow at one or more of the following parts:

• The space in the centre of the spine;
• The canals where the nerves branch out from the spine, or;
• The space between the vertebrae.

 

Causes

Spinal stenosis can occur due to a variety of causes, including the following:

• Arthritis - this is the most common cause;
• Disc herniation;
• Thickening of ligaments;
• Compression fractures - common for people who have osteoporosis;
• Injuries that dislocate the spine, or cause fractures that may cause bone fragments that penetrate the spinal canal;
• Congenital conditions in which the spinal canal is too small from birth;
• Paget's disease (which causes abnormal enlarging and weakening of bone);
• Ankylosing spondylitis;
• Acromegaly, and;
• Tumours of the spine.

Types

The spine is made up of three regions - the cervical, thoracic and lumbosacral spine.

Lumbar stenosis is the most common, with around 75% of cases of stenosis occurring in this region. Lumbar stenosis commonly involves compression of the nerve roots of the lower back, leading to sciatica.

Cervical stenosis is less common, but is potentially more serious, as it can affect the muscles that help with breathing.

Thoracic stenosis is the least common type and can be associated with pain in the ribs.

Signs and symptoms

Some people with spinal stenosis may not experience any symptoms. For others, if the narrowing puts pressure on the nerves or spinal cord, there may be symptoms such as:

• Numbness or weakness in the arms or legs;
• Cramping and pain in the arms or legs;
• Sciatica, or pain that radiates down the back of one leg;
• Foot disorders, and;
• Loss of bladder or bowel control.

Methods for diagnosis

Medical history

To help diagnose the cause of your symptoms, your doctor will take a detailed medical history, including your symptoms and past injuries, and ask questions about your overall health.

Physical examination

Your doctor will perform a physical examination to assess your strength, sensation and reflexes.

Imaging tests

X-rays

X-rays can be used to show any bone-related causes of spinal stenosis, such as osteoarthritis and bone spurs.

Computerised tomography (CT)

CT scans can provide detailed images of the spinal column to help better diagnose bone-related causes.

Magnetic resonance imaging (MRI)

MRI scans can be used to detect injury or disease of the soft tissue, such as disc herniation and tumours of the spine.

Bone scan

Bone scans can be useful in detecting fractures, infection or arthritis, but because they cannot differentiate between disorders, they are most commonly used alongside other imaging tests.

Types of treatment

Non-surgical

Exercise

Exercise can be used to build up strength in the muscles of your arms and legs. Exercise can improve your balance, ability to walk, bend, move about and control pain.

Medications

Over-the-counter medications, such as paracetamol and ibuprofen, may provide relief from pain. Some people may be prescribed specific medication to ease muscular spasms.

Corticosteroid injection

Corticosteroids may be injected directly into the affected area around the spinal cord to provide temporary, or sometimes permanent, pain relief. These injections are not for regular use and are generally limited to only a few times each year.

Acupuncture

Acupuncture may prove effective in treating symptoms of mild to moderate cases of lumbar stenosis.

Surgery

When non-surgical treatment has not provided effective relief from symptoms, surgical treatment may be an option for some people. There are different procedures that can be used to alleviate the symptoms, including:

• Decompression laminectomy - to remove the bony spurs in the spinal canal and free up space for the nerves and spinal cord, or;
• Spinal fusion - in which additional bone is used to fuse two vertebrae together, which stops movement at the painful segment.

Surgical risks may include blood clots, infection, failure to provide relief and nerve injury.

Potential complications

Severe cases of spinal stenosis may lead to chronic pain, paralysis, or faecal and urinary incontinence, which can be disruptive to normal life.

Prognosis

For most people, there is good relief from symptoms without surgery. However, for others, non-surgical treatment may prove ineffective and surgery will be a good option.

Prevention

You may be able to lower the likelihood of spinal stenosis by:

• Keeping your back healthy by engaging in regular exercise;
• Maintaining a healthy weight;
• Having good posture, and;
• Not smoking.