Spinal stenosis is the term given to a narrowing of the spinal canal – the space in the back in which the spinal cord runs. This occurs to some extent in most people as part of the aging process and is a common cause of back pain. Spinal stenosis can also cause numbness of areas of skin – especially of the legs. It can also cause weakness of the legs or other muscles. Spinal stenosis most commonly affects the lower, lumbar spine and often causes lower back pain for this reason.
The condition occurs in both men and women although women require treatment more often then men. It develops progessively with age but generally presents over the age of 50-60 years.
Causes of spinal stenosis
Spinal stenosis occurs to some extent in everyone during aging. A narrowing in the spinal canal may develop due to overgrowth of the soft tissues or bone in the spine, or due to some protrusion from the vertebral discs. Most commonly it is a combination of factors that leads to the narrowing causing symptoms. Arthritis is found to be the main cause most frequently.
Often, one causal factor can end up worsening another. For example, as the vertebral discs become less supportive, more pressure is put on the facet joints of the spine which in turn can lead to worsening arthritis and overgrowths of bone. The loss of height in the vertebral discs and any protrusion from the discs can also cause a reduction in the space available within in spinal canal.
The common symptoms of spinal stenosis are listed below.
- Back pain – often worse when standing up straight and better when bending forwards. May also be made worse by walking
- Sciatica – particularly shooting or burning pains in legs
- Weakness of the legs
It is important with any new medical problem or symptoms to seek medical attention from a qualified doctor at the first opportunity. This is particularly true if your back pain meets any of the criteria discuss in our article on the red flags of back pain and cancer.
Your doctor will take a history of your symptoms from you and will also request further tests to confirm the diagnosis if they feel it is necessary. These tests may include an x-ray or a magnetic resonance imaging (MRI) scan. These tests are often only requested by a specialist back doctor and after simple treatment measures have failed – this is because in the majority of cases, back pain improves and gets better.
Treatment of spinal stenosis is generally not surgical to start with although back surgery may be required later.
Early treatment options:
- Simple painkillers – e.g. paracetamol or anti-inflammatory drugs (discuss with your doctor before taking these regularly, especially if you have a history of asthma or stomach problems such as ulcers).
- Physiotherapy – very effective for almost all types of back pain and an excellent first treatment
- Chiropractic – Associated with some excellent results and now a recommended treatment option for back pain but always consult your doctor first
- Injections – A back doctor may advise trying a steroid injection into an area of the spine to see if this relieves your symptoms. The injections can either be to the space around the spinal cord or to the facet joints. They are often only a temporary measure and can only be repeated a limited number of times.
There are several types of back surgery which can be helpful in spinal stenosis. There have been recent advances in spinal surgery for this condition and the main one of these is listed below. The most common procedures performed, however, are the laminectomy or the spinal fusion.
- Laminectomy: Involves removal of part of the bone and ligaments of the vertebrae in the spine at the level of the spinal stenosis. This creates more space in the spinal canal and is often very effective.
- Spinal fusion: Involves using a variety of different techniques to eliminate movement at a level of the spine to prevent any narrowing of the spinal canal with movements of the back.
- Interspinous process implants: These are devices which are implanted between the spinous processes of the spine – the spikes of bone attached to the the back of each vertebrae. The implanted device expants the space between these spinous processes and as a result can create more space in the spinal canal. The implants mimic the position the spine is in when bending forwards – the position where more people suffering from spinal stenosis find their symptoms ease.
There as risks involved with all surgery and back surgery is certainly no exception. The risks should be discussed extensively with your back doctor and understanding the recovery from back surgery is also important. In general, however, four out of five patients undergoing back surgery for spinal stenosis have a good outcome and regain good function and a good lifestyle.