Narrowed spinal canal syndrome – spinal stenosis
Over the course of a lifetime, the lower, lumbar vertebrae of the spine come under sustained pressure and 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 and 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 that below it (spondylolisthesis), either forwards (ventro- or anterolisthesis) or backwards (retrolisthesis). This slippage can lead to 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 canal is opened and the structures causing compression such as bony outgrowths, thickened ligaments, fatty deposits or herniated intervertebral discs are removed. Compressed nerve roots lying at the far sides of the spinal canal can be relieved in a targeted fashion. 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. This operation can also be performed at multiple levels (see computer simulation on the left).
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 for stability. 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 you will naturally be cared for by a multi-disciplinary team and supported by a team of physiotherapists who will assist you with mobilisation and returning to pain-free movement.