Spondylolisthesis

Spondylolisthesis refers to a condition in which one vertebra slips forward relative to the one below it. This can occur as a result of age-related changes, stress on the spine, or, in some cases, a defect in a portion of the bone.

Degenerative spondylolisthesis is the most common type and develops over time as the discs and joints lose their structural integrity. The facet joints may become elongated, loosen, and develop hypermobility, contributing to abnormal motion between the vertebrae.

Isthmic spondylolisthesis occurs when there is a small defect or stress fracture in a specific part of the vertebra called the pars interarticularis, often developing earlier in life.

As the vertebra shifts, it can contribute to narrowing of the spinal canal (stenosis) or compression of nearby nerve roots. In some cases, this narrowing is present at rest (static stenosis), but movement or loading can worsen the slippage, further narrowing the canal (dynamic stenosis).

Symptoms may arise from different mechanisms. Some patients experience localized back pain due to inflammation of the facet joints. Others develop radicular symptoms when a single nerve root is compressed, or neurogenic claudication when multiple nerve roots are affected by the narrowing.

Symptoms vary depending on the degree of slippage, the presence of instability, and whether nerves are affected.

• Lower back pain, often worsened by standing or lumbar extension
• Pain that improves with sitting or bending forward
• Stiffness or reduced mobility
• Sciatica (radiating pain into the leg)
• Numbness or tingling in the legs
• Leg weakness or fatigue with walking
• In some cases, difficulty walking due to neurogenic claudication

Diagnosis is based on clinical evaluation and imaging when appropriate:

• X-rays (including dynamic flexion/extension views): used to identify and measure the degree of slippage and assess for instability
• MRI: evaluates nerve compression, disc changes, and associated stenosis
• CT scan: may be used in selected cases to better define bone anatomy, including defects of the pars interarticularis

Conservative (non-surgical) treatment

• Activity modification and education
• Physiotherapy focused on core stability and movement control
• Medications for pain management

Interventional treatments

• Targeted injections, including facet or nerve root injections in selected cases

Surgical treatment

Surgery may be considered when symptoms are severe, progressive, or not responding to conservative care.

Our approach focuses on identifying the primary pain generator — whether mechanical (facet-related), neurological (nerve compression), or due to instability. In selected patients without significant hypermobility or mechanical back pain, decompression alone may be an appropriate option.

However, it is important to recognize that the underlying forces contributing to the spondylolisthesis may continue to evolve over time. In some cases, this may eventually require additional stabilization in the form of fusion.

When surgery is indicated, techniques are selected to address the underlying problem while preserving as much normal spinal function as possible and avoiding unnecessary fusion whenever appropriate.