Lumbar spondylolisthesis is the sliding of a lumbar vertebra relative to the vertebra just below and dragging the rest of the spine with it. Three types of spondylolisthesis correspond to three different causes: the repetition of mechanical stresses on the spine, osteoarthritis of the joints or a congenital malformation. Surgical operation is only recommended in the event of failure of medical treatment or the presence of neurological motor or sphincter disorders.

Definition of spondylolisthesis

Lumbar spondylolisthesis is the sliding of a lumbar vertebra forward and down relative to the vertebra just below and dragging the rest of the spine with it. Spondylolisthesis presents four stages of increasing severity with, in the extreme, the fall of the vertebra in the small pelvis.

Types de spondylolisthésis

There are three types of spondylolisthesis:

• Lumbar spondylolisthesis by isthmic lysis affects 4 to 8% of the population. It is secondary to the fracture of the isthmus, the bony bridge connecting one vertebra to the other. The fifth and last lumbar vertebra (L5) is most often affected. The disc between the two vertebrae is crushed and decreases in height: we speak of associated disc disease;
• Degenerative lumbar spondylolisthesis or osteoarthritis spondylolisthesis is secondary to the development of osteoarthritis of the joints. The fourth and fifth lumbar vertebrae are usually affected but the slippage is generally not very important. The disc between the two vertebrae wears out and is crushed and decreases in height, we then speak of associated disc disease;
• The rarer dysplastic lumbar spondylolisthesis is of congenital origin.

Causes of spondylolisthesis

Contrary to popular belief, lumbar spondylolisthesis by isthmic lysis is not due to a single trauma in childhood or adolescence but to the repetition of mechanical stresses on the spine, which lead to a “fatigue fracture” of the isthmus (bony bridge between two vertebrae).

Degenerative lumbar spondylolisthesis or arthritic spondylolisthesis is, as the name suggests, linked to osteoarthritis of the joints.

Dysplastic lumbar spondylolisthesis is secondary to a malformation of the last lumbar vertebra with an abnormally elongated isthmus

Diagnostic of spondylolisthesis

The x-ray of the lumbar spine allows the diagnosis of the type of spondylolisthesis and the evaluation of its severity based on the slip of the vertebra.

The radiological assessment is completed by:

• A scan of the lumbar spine to visualize the isthmus fracture;
• Magnetic resonance imaging (MRI) of the lumbar spine allows, if necessary, a better visualization of the compressed nerve root, an analysis of the compression of the dural fornix or ponytail (lower part of the dura containing the roots motor and sensory nerves of the two lower limbs and of the bladder and rectal sphincters) and an analysis of the condition of the intervertebral disc between the two vertebrae;
• Electromyography is used to assess the health of muscles and the nerve cells that control them. It is only done if the patient does not have all of the characteristic symptoms of spondylolisthesis or if the symptoms are mild.

People affected by spondylolisthesis

Lumbar spondylolisthesis by isthmic lysis affects 4 to 8% of the population. It is frequently observed in high-level athletes practicing activities requiring frequent spine rotations and arched postures.

Dysplastic lumbar spondylolisthesis most often affects adolescents and young adults.

Factors favoring spondylolisthesis

Lumbar spondylolisthesis by isthmic lysis is favored by the following factors:

• Regular sports activities involving frequent spine rotations and arching postures such as rhythmic gymnastics, dancing, throwing sports, rowing or horse riding;
• Work positions requiring leaning forward postures;
• The regular carrying of heavy loads or a heavy backpack in children.

Degenerative lumbar spondylolisthesis can be favored by:

• Menopause ;
• Osteoporosis.

Lower back pain

Long well tolerated, spondylolisthesis is often discovered by chance on an X-ray assessment of the pelvis or in adulthood during the first lower back pain.

Low back pain

One symptom of spondylolisthesis is lower back pain, relieved by a lean forward position and worsened by a lean back position. The intensity of this low back pain varies from the feeling of discomfort in the lower back to the sharp pain of sudden onset – often following the carrying of a heavy load – called lumbago.

Sciatica and cruralgia

Spondylolisthesis can lead to compression of a nerve root where the nerve exits the spine and cause pain in one or both legs. Sciatica and cruralgia are the two representatives.

Cauda equina syndrome

Spondylolisthesis can cause compression and / or irreversible damage to the nerve roots of the dural cul de sac. This cauda equina syndrome can cause sphincter disorders, impotence or prolonged and unusual constipation …

Partial or complete paralysis

Spondylolisthesis can be responsible for a partial paralysis – sensation of letting go of the knee, inability to walk on the toe or heel of the foot, impression of a foot scraping the ground when walking… The pressure exerted on the nerve root can lead to irreversible damage with the ultimate consequence of complete paralysis.

Other symptoms

• Neurogenic claudication or the obligation to stop after a certain distance traveled;
• Paresthesias, or disturbances in the sense of touch, such as numbness or tingling.

Medical treatment is recommended when the spondylolisthesis is painful but no neurological sign is diagnosed. This treatment varies depending on the pain:

• Analgesics as a basic treatment for lumbar pain associated with non-steroidal anti-inflammatory drugs (NSAIDs) for 5 to 7 days in the event of a crisis;
• Rehabilitation including exercises to strengthen the abdominal and lumbar muscles;
• In the event of a recent fracture of the isthmus or severe low back pain, immobilization with a Bermuda cast incorporating a thigh on one side only may be advised to relieve pain.

In the event of failure of medical treatment or in the presence of neurological motor or sphincter disorders, surgery for spondylolisthesis may be required. It consists in performing arthrodesis or definitive fusion of the two painful vertebrae. Arthrodesis can be associated with a laminectomy: this operation consists in releasing the compressed nerves. This intervention can be performed minimally invasively using two small lateral incisions, with the advantage of significantly reducing postoperative lower back pain.

Some precautions should be taken to avoid the appearance or worsening of spondylolisthesis:

• Request a job adaptation in the event of jobs with strong constraints: repeated leaning forward position, carrying heavy loads, etc.
• Avoid sports activities in hyper extension;
• Do not carry heavy backpacks on a daily basis;
• Do not eliminate the practice of leisure sports which, on the contrary, strengthens the lumbar and abdominal muscles. ;
• Perform radiographic monitoring every five years.