The word spondylolisthesis derives from two parts – spondylo which means spine and listhesis which means slippage.
Spondylolisthesis is a forward slip of one vertebra relative to another. It can be congenital (present at birth) or develop in adolescence or childhood. The disorder may result from the physical stresses to the spine from physical activity, trauma or general wear and tear.
There are two common types of spondylolisthesis – Degenerative and Lytic. Degenerative Spondylolisthesis occurs in older patients and is caused by the wear and tear of the disc and facet joints. There is no tear in the lamina (part of the vertebra at the back).
The spinal canal narrows down squeezing the nerves, leading to increased leg pain or weakness on walking which is eased when leaning forward or sitting down. Patients suffering from degenerative spondylolisthesis also complain that although they cannot walk straight, they find their pain relieved by leaning forward such as over a shopping trolley or cycling.
In Lytic Spondylolisthesis there is a break in the lamina and one vertebra slips forwards on the other. The spinal canal is usually not narrowed down, but the nerves can be squeezed causing leg pain and difficulty walking.
Spondylolisthesis may result in back or neck pain, but extremities can be involved if the spinal cord or nerve roots are compressed or irritated.
Many people with Spondylolistheis will have no symptoms, and only become aware that there is a problem when it is revealed on an x-ray for a separate problem.
However there are several symptoms that are often linked to spondylolisthesis:-
- Increased pain in the low back, particularly after exercise
- Increased lordosis (i.e. swayback)
- Pain and/or weakness in one or both thighs or legs
- Reduced ability to control bowel and bladder functions
- In cases of advanced spondylolisthesis changes may occur in the way people stand and walk; for example, development of a waddling style of walking. This causes the abdomen to protrude further, due to the low back curving forward, the chest may seem shorter and muscle spasms in the low back may occur.
Treatments vary with the severity of the spondylolisthesis. Most patients only require physical therapy combined with some modifications to their lifestyles.
If the pain is coming from nerve root irritation, epidural steroid injections may be considered. For cases where pain is not responding to therapy, or the slip is very severe, surgery is a good option to consider. The surgery involves stabilizing the spine and freeing up the nerve roots – a decompression and fusion operation.