Sitting and bending are no problem, standing and walking, on the other hand, hardly bearable? With symptoms like these, spinal stenosis is the likely diagnosis – for older patients, it’s the most common reason for spine surgery. The spinal canal is the channel in the spine where the spinal cord is well protected. Its wall is formed by several structures: the intervertebral discs, the intervertebral joints, and the ligamentum flavum, a tight ligament that stabilizes the spine longitudinally at the back.
Causes of spinal stenosis
But this encasement comes at a price: for one thing – in the case of a herniated disc – the discs can bulge into the spinal canal, reducing the space available for the nerves. On the other hand, with increasing age, signs of wear and tear occur in the intervertebral joints, as in other bones and joints. Osteoarthritis leads to bony protrusions. These bony protrusions narrow the spinal canal and reduce the exit ports of the nerves. Spinal canal stenosis is aggravated when the spine is extended, since the ligamentum flavum is then rather short and thick, thus narrowing the space inside even more. When the spine is bent forward, for example when bending over, the ligament is pulled apart and thus thinner. Therefore, the discomfort then subsides almost immediately.
Spinal stenosis: symptoms and diagnosis
Spinal stenosis occurs mainly in the lumbar spine (LS) (lumbar spinal stenosis), more rarely as cervical spinal stenosis of the cervical spine (C-spine) and very rarely in the thoracic spine (C-spine). The symptoms of spinal canal stenosis result from the impaired function of the spinal cord nerves due to the narrowing. The symptoms are typical: depending on the body position, there is pain in the back and often even more pain in the legs. The pain is pronounced when standing and walking, but is absent or barely present when bending over and sitting. In addition, there is often a feeling of heaviness or cramping in the legs, as well as numbness in the buttocks, which can extend into the legs. Affected persons with spinal canal stenosis often know all the seats around them, as they can hardly stand holding themselves up straight. They therefore also often walk hunched over. Due to the pain or numbness in the leg, they also often limp (spinal claudication). Over time, spinal stenosis also limits their range of motion and activities of daily living. Diagnosing spinal stenosis usually does not cause any problems for the physician due to the typical symptoms. X-rays, computer tomography and magnetic resonance imaging can be used to differentiate other clinical pictures, such as polyneuropathy. A contrast medium injected in the process (myelography) shows the constrictions particularly clearly.
Treating spinal stenosis
Spinal stenosis therapy is initially conservative – the measures are the same as for a herniated disc: physiotherapy exercises, anti-inflammatory painkillers (anti-inflammatory drugs) and possibly cortisone injections into the spinal canal. In addition, special girdles are offered for spinal stenosis patients to support the spine in a posture that relieves pressure on the spinal canal and nerves. If these measures do not sufficiently improve the symptoms of spinal stenosis, surgery must be considered for treatment. Depending on the severity of the symptoms, minimally invasive measures and classic surgery are available. In minimally invasive surgery, implants (called spreaders or interspinous spacers) are inserted between the spinous processes through a skin incision and local anesthesia, which push the vertebrae apart and thus widen the spinal canal. Because the surgical procedure is relatively new, long-term results are still pending.
Surgery: long-term results are good
In most cases, surgical decompression of the nerve roots is ultimately essential for the treatment of spinal stenosis. In the past, a complete laminectomy was performed for this purpose, meaning that all structures at the back of the spinal canal were removed: not only the thickened ligamentum flavum and the bony prominences at the joints, but also the spinous processes of the vertebrae and the ligamentous connections between them. However, the resulting instability was problematic, often leading to displacement of the structures, such as spondylolisthesis, and renewed complaints. Therefore, additional stabilization (spondylodesis) was then often necessary.For this reason, spinal stenosis surgery today usually preserves the spinous processes and small ligaments and removes only the bony extensions and the thickened ligamentum flavum. Additional stabilization procedures are needed only if larger bony areas need to be removed. Long-term outcomes are good-most spinal stenosis sufferers are free of symptoms for years after surgery.
