What is lumbar spinal stenosis?

operaciones de columna vertebral

Lumbar spinal stenosis (LSS) is a condition that consists of a narrowing of the lumbar spinal canal, causing compression of the nerve roots that innervate the lower extremities. The spinal canal is formed by the inner canal of the vertebrae, the intervertebral discs and the different ligaments that ensure spinal stability. In some cases, it will be necessary to consider a spine operation as the best possible solution, although this is not always necessary.

Occasionally, patients suffer from a congenital defect that does not become apparent or cause symptoms until adulthood. However, in most cases, this condition is of osteoarthritic and degenerative origin, and therefore increases in frequency with age. It can cause symptoms in different ways such as low back pain (pain in the territory of a specific nerve root), loss of lower extremity strength, etc. Nonetheless, the most frequent associated symptom is neurogenic claudication or pseudoclaudication. This condition consists in a growing inability to walk, at first, medium distances, and eventually, in advanced cases, just a few steps.

There is a sensation of pain in both legs, although sometimes there is numbness, tingling or a feeling of loss of strength. Symptoms are usually relieved when the affected person sits down, thus expanding the diameter of the lumbar canal by bending the lumbar spine. As it is a degenerative condition and usually undergoes slow progression, there are many degrees of severity, from mild to extreme interference with activities of daily living.

How is it diagnosed?

As this condition is frequent, first of all it is necessary to question the patient as to their medical history so as to detect data suggesting the existence of a neurological origin of the symptoms present in the lower extremities and to rule out joint pathologies or other conditions. As we have said before, the progressive limitation of the distances the patient is able to walk, which become shorter and shorter, and the need to flex their trunk or to sit down to relieve symptoms, are highly suggestive.

By means of a physical exam, the patient’s strength, sensitivity and osteotendinous reflexes in the lower extremities are assessed. The spine is also explored, especially the lumbar segment. Once there is a clinical suspicion of symptomatic spinal stenosis, we proceed to request imaging tests to confirm this diagnosis.

  1. Magnetic resonance: is the main tool we have available to visualize soft tissues in detail (nerves, discs and ligaments, among others), and thus to confirm lumbar spinal stenosis.
  1. CT: this exam gives us detailed information on the bony structures of the spine. It is useful to assess the degree of bone involvement in the stenosis and the existence of added features, such as osteoarthritis, osteophytes, spondylolysis or other anomalies, that may affect treatment.
  1. Dynamic or functional lumbar X-rays: These are conventional X-rays of trunk flexion and extension in profile. They make it possible for us to determine if there is vertebral instability.
  1. Scoliogram or telemetry X-rays: An X-ray of the entire spine on one X-ray film makes it possible to assess whether there is an alteration of the balance of the spine and its curvature that contributes to the condition and that requires correction.
  1. Electromyography: We use it in cases of doubt to assess the degree of nerve involvement. In some cases, it makes it possible to differentiate conditions of a neurological origin from others, and to determine whether the cause is compression or not (and, therefore, if it has a surgical solution); and, in the case of actual nerve compression, whether this is at the level of the nerve root in the spine or is a peripheral problem in the limb.

All these studies, plus the clinical information gathered during a physical exam and detailed taking of a medical history, lead to the decision on treatment.

While many cases with a mild condition can improve with conservative treatment, other cases will require more aggressive treatments. Conservative treatments essentially include maintaining an adequate weight in relation to height and physical constitution, and changing personal and professional life habits, such as the use of ergonomic furniture, postural hygiene and moderate gentle routine physical activity. Many cases will require additional support and guidance, especially at the beginning, until the acute condition is controlled and healthy habits are acquired.

In the absence of specific techniques for individual pathologies, at Instituto Clavel we decided to create a specific protocol consisting of physical therapies and appropriate exercises for different spine conditions according to the different phases of their constant evolution. This philosophy resulted in FisioSpine, a method created by our team of expert spine physiotherapists together with our team of neurosurgeons, who assist and provide indications throughout the recovery process.

We know, however, that sometimes conditions caused by spinal cord compression, such as lumbar stenosis, are so advanced and severe they do not respond favorably to conservative treatment. Some rebellious cases, although they do not show special structural involvement in the imaging tests, will need to be referred to our Pain Unit for palliative treatment, but fortunately many of the severe cases can be cured by means of surgery.

At Instituto Clavel, our team of spine surgeons is trained in different techniques and access routes to the spine so that they can choose the treatment that best suits our patients with the lowest possible risk. In general, the treatment of canal stenosis will consist of a direct posterior decompression by means of a laminectomy, that is, the resection of the vertebral bone and ligament that form the posterior part of the vertebral canal to widen the space for the nerve roots.

In some cases with localized spine canal narrowing and compression, the use of cutting-edge surgical microscopes allows us to perform microsurgery (MIS surgery) in order to decompress the spinal canal in a minimally invasive way. Sometimes the patient suffers from some other structural problem affecting the lumbar spine, such as degenerative disc disease, facet arthropathies, spondylolisthesis, etc., which will make it necessary to combine decompression with the use of implants.

With techniques such as a lateral lumbar approach (TLIF, XLIF), we can, using this minimally invasive approach that guarantees a quick recovery, elevate a collapsed disc and return to its initial position the ligament inside the spinal canal that was folded and compressing the nerve roots.

There are cases with associated instability or very advanced degeneration that will require fusion surgery, since we will need to open up a significant portion of the vertebra and the ligament to ensure a good decompression that persists after tissue healing.

When necessary, for the safety of the patient and the success of the surgery, we will use screw implants and a posterior approach. For this kind of procedure, we have several advanced technology tools, such as O-Arm 2, a leading-edge intraoperative CT (scanner) that allows us to collect images in the operating room so as to implant transpedicular screws using virtual navigation and thus optimizing their positioning, and also makes it possible to check the correct positioning of the implants before the end of surgery. With this system we can perform minimally invasive instrumented surgeries, since the incision necessary for the introduction of material is minimal.

In addition, to ensure patient safety, operations with a significant neurological risk are always carried out under intraoperative neurophysiological monitoring. This means the team’s neurophysiologist carries out continuous control of nerve activity throughout the surgical procedure to prevent nerve injuries.

Given the wide range of resources that we can make available to our patients, we consider it is essential to study each case individually and offer our patients the option with the highest probability of success, lowest surgical risk and quickest recovery time.