Spinal Stenosis

Spinal canal stenosis, also known as spinal canal narrowing, is the pathological narrowing of the spinal canal in which the spinal cord is embedded.

Over the course of a lifetime, the lower lumbar vertebrae of the spine comes under sustained pressure. This this leads to degenerative changes. Narrowed spinal canal syndrome is usually the result of a number of factors working together:

• the intervertebral discs lose their height and may bulge out into the spinal canal,
• ligaments become thickened,
• bony splinters (spondlyophytes) can form on the vertebral bodies
• the joints between the vertebrae undergo changes (spondyloarthrosis).

The resultant narrowing (stenosis) of the spinal canal ultimately leads to compression of the nervous structures residing in the canal.

The clinical picture of spinal canal stenosis varies depending upon the nerve root affected. Typically, pains radiate into the front and back of the leg which, in contrast to disc herniations, seldom correspond to a particular spinal root and its associated muscle and skin distributions.

While walking, the narrowed spinal canal causes compression of the spinal nerve roots within the canal and disturbs their blood supply. The resulting pain generally subsides if one stops and sits down for a moment or leans forward – relieving the compressed nerve roots and restoring their blood supply. Over the years, spinal stenosis is generally progressive, with the result that the distance a patient can walk without symptoms steadily reduces.

The diagnosis of spinal canal stenosis is made by performing MRI and CT imaging of the lumbar spine in patients presenting with typical symptoms. This may show a slip of one vertebral body on the underlying one (spondylolisthesis), either forwards (ventro- or anterolisthesis) or backwards (retrolisthesis). This slippage can cause a narrowing of the canal and trap or stretch one or more nerve roots, causing pain and functional deficits.

Treatment for spinal canal stenosis consists, in mild cases, of physiotherapy to support building up the back and stomach musculature with the target of stabilising and relieving pressure on the vertebral column. Inflammatory changes can be managed with medical therapy.

If symptoms continue to worsen despite these measures, surgical intervention may be indicated. Using microsurgical techniques, the spinal canal is opened and the structures causing compression such as

• bony outgrowths,
• thickened ligaments,
• fatty deposits or
• herniated intervertebral discs

are removed.

In most cases it is possible to decompress the spinal canal using a minimally-invasive technique through a small window made in the bone on one side. In this way the spinal canal at the level of the window can be completely cleared of space-occupying structures while maintaining the stability of the vertebral column. The key to post-operative structural stability is to spare the midline structures as well as the facet joints. That way, the operation can also be performed at multiple levels.

In cases of spondylolisthesis it is often necessary to fuse the affected vertebral bodies (a spondylodesis) in addition to a decompression operation. This is achieved through the placement of strong screws into the vertebral body which are subsequently connected with metal rods and fixated. A titanium cage may also be inserted into the space between the vertebral bodies to serve as scaffolding during the bony fusion process.

In Klinik Hirslanden, this operation is performed using intra-operative CT, increasing the precision and reducing the need for X-ray radiation.

Before and after your operation a multi-disciplinary team will take care of you and a team of physiotherapists will assist you with mobilisation and returning to pain-free movement.