Spondylolisthesis

Why does spondylolisthesis occur? All the information about this disorder: causes, symptoms, and types.

Symptoms and Causes

Spondylolisthesis is the displacement of a vertebra relative to the adjacent lower vertebra. It can occur in any vertebra of the spine, although it is most common in the lumbar region, mainly at the L5-S1 level, although it is also common at the L3-L4 or L4-L5 levels.

The grading of spondylolisthesis is classified based on the percentage of the vertebral body that has displaced:

Grade I spondylolisthesis: displaces up to 25% of the vertebra.
Grade II spondylolisthesis: from 25% to 50%.
Grade III spondylolisthesis: from 50% to 75%.
Grade IV spondylolisthesis: from 75% to 100%.
Grade V spondylolisthesis (spondyloptosis): displaces 100% of the vertebra.

Displacement can occur in any direction. Based on this parameter, the types of spondylolisthesis are:

Anterolisthesis: forward or anterior displacement. This is the most common type.
Retrolisthesis: backward or posterior displacement.
Laterolisthesis: lateral displacement.

Symptoms

If the spondylolisthesis is mild, with minimal displacement, symptoms may not appear. If they do manifest, the following are common:

Pain in the back over the affected area.
Pain in the legs that may radiate to the buttocks, in the case of lumbar spondylolisthesis.
Pain in the arms, if it is cervical spondylolisthesis.
Stiffness in the back.
Muscle stiffness, especially in the hamstrings.
Postural changes due to stiffness: walking with short steps and slightly bent knees.
Numbness or tingling in the legs.
Gait claudication: pain increases when standing or walking and forces the person to stop and sit.
Gait instability: pelvic rotation to compensate for lumbar stiffness.

Causes

Spondylolisthesis is also classified based on its origin:

Type I or congenital spondylolisthesis: present from birth, it results from abnormalities in the upper facets of the sacrum or the lower facets of the L5 vertebra. It is also called dysplastic spondylolisthesis.
Type II or isthmic spondylolisthesis: caused by spondylolysis, which is a fissure or fracture due to overload in the pars interarticularis, the isthmus of the posterior arch of the vertebral body. The injury leads to insufficient fixation and subsequent slipping. This is a very common type.
Type III or degenerative spondylolisthesis: caused by the natural degeneration of vertebral structures and tissues, such as the disc, ligaments, or facet joints. It is the most common form.
Type IV or traumatic spondylolisthesis: caused by fractures or other injuries from impacts or falls. It is rare.
Type V or pathological spondylolisthesis: resulting from an infection, a tumor, or another bone condition like osteoporosis.
Type VI or iatrogenic spondylolisthesis: caused by surgery on the spine. It is also called post-surgical spondylolisthesis.

Risk Factors

Risk factors for developing spondylolisthesis include:

Age: isthmic spondylolisthesis is more common in adolescents or young adults, while degenerative spondylolisthesis appears in patients over 50 years old.
Sex: degenerative spondylolisthesis is more frequent in women.
Sports practice: isthmic spondylolisthesis is common in athletes, especially in sports that overload the back, such as gymnastics, weightlifting, or throwing sports.
Presence of bone disorders.
Previous spine surgery.
Obesity: excess weight adds pressure on the lumbar area.

Complications

If spondylolisthesis is left untreated, the persistent pain associated with it can lead to reduced mobility and inactivity, affecting the patient's quality of life. In severe cases, with significant displacement, the displaced vertebra may compress a nerve and cause permanent damage. Additionally, it can compress the spinal cord, leading to narrowing, a condition called spinal stenosis. Both nerve and spinal cord damage can result in neurological problems such as incontinence or sensory disorders.

Prevention

Some measures can be taken to reduce the risk of spondylolisthesis:

Perform specific exercises to strengthen the back and abdomen.
Engage in sports and activities that do not overload the spine, such as swimming or cycling.
Maintain a healthy weight.

What doctor treats spondylolisthesis?

Spondylolisthesis is diagnosed and treated in the unit of traumatology and orthopedic surgery.

Diagnosis

Spondylolisthesis is confirmed through the following tests:

Physical examination: In addition to palpating the spine, the gait, mobility, flexibility, and pain levels of the patient are assessed.
Plain radiography: X-ray images show vertebral displacement. Views from different angles are taken to identify the direction of displacement. X-rays also help rule out conditions with similar symptoms, such as disc herniation or spinal stenosis.
Computed tomography (CT): This test provides high-precision X-ray images that can reveal bone lesions and abnormalities in the spine that may have caused the spondylolisthesis.
Magnetic resonance imaging (MRI): Images obtained using magnets and radiofrequency allow detailed visualization of the body's soft tissues, confirming the degree of nerve or spinal canal involvement.

Treatment

Asymptomatic spondylolisthesis does not require treatment. When symptoms are present, treatment depends on the severity of the vertebral displacement. Options include:

Administration of analgesics or non-steroidal anti-inflammatory drugs to relieve mild or moderate pain.
Administration of corticosteroids in case of severe pain. They can be taken orally or injected into the affected area.
Physiotherapy: mainly exercises for flexion and extension of the spine aimed at stabilizing the displaced segment and strengthening muscles for pain-free movement and improved flexibility.
Orthotics: The use of a lumbar brace helps stabilize the area and retain heat, reducing pain and facilitating movement.
Low-impact aerobic exercises such as walking, swimming, or cycling help reduce pain.
Surgery: in severe cases that do not improve with previous treatments or present neurological symptoms, surgical intervention is necessary.
Decompressive laminectomy: Involves removing a portion of the vertebral lamina (the posterior part of the vertebra) to relieve pressure on the nerves or spinal cord.
Spinal fusion or arthrodesis: Involves fusing two or more vertebrae to prevent movement. A bone graft is placed in the intervertebral space, which ultimately forms a solid bone mass with the vertebrae involved. The fusion can be facilitated by the implantation of rods, screws, or plates. The bone graft can be taken from the patient, a donor, or artificial bone material.