Lumbar Spinal Stenosis & Spondylolisthesis

What are lumbar spinal stenosis & spondylolisthesis?

Two degenerative conditions that often coexist, leading to compression of spinal nerve roots.

Lumbar spinal stenosis refers to narrowing of the spinal canal and/or neural foramina in the lumbar region. When the available space within the spinal canal and around the nerve roots is reduced, the roots become mechanically compressed and ischemic, causing pain, numbness, weakness, and the characteristic neurogenic intermittent claudication (leg pain/heaviness during walking that improves with sitting).

Spondylolisthesis is the forward displacement of one vertebra relative to the one below, due to degenerative changes in the facet joints and intervertebral disc (degenerative spondylolisthesis) or to a defect of the pars interarticularis (isthmic spondylolisthesis). The slippage may exacerbate stenosis—particularly within the foramina—and lead to severe radicular pain.

How common are they & who is at higher risk?

These are common degenerative disorders of the spine, especially in older adults, but they can also occur in younger individuals, including athletes.

Higher-risk groups for lumbar stenosis and spondylolisthesis include:

• Adults over 55–60 years with degenerative changes of discs, joints, and ligaments.
• Individuals with occupations or activities that strain the lower back (heavy manual labor, repetitive bending/extension, vibration exposure).
• Younger athletes (gymnastics, weightlifting, soccer) with repetitive hyperextension—at risk for spondylolysis.
• Patients with scoliosis, congenitally narrow spinal canals, or other anatomic variants.
• Those with systemic connective tissue disorders (e.g., Marfan, Ehlers–Danlos, NF1).
• Obesity, smoking, and sedentary lifestyle, which increase mechanical stress on the spine.

Importantly, a proportion of older individuals demonstrate asymptomatic stenosis on imaging without clinical complaints. Therefore, treatment decisions are always based on symptoms and functional impact, not imaging findings alone.

How does stenosis develop—what happens anatomically?

Lumbar spinal stenosis is the result of a degenerative cascade affecting discs, joints, and ligaments.

Key mechanisms include:

• Intervertebral disc degeneration—loss of disc height, dehydration, bulging, or herniation into the spinal canal or foramina.
• Facet joint hypertrophy—osteophyte formation projecting posteriorly and narrowing the foramina.
• Thickening and “buckling” of the ligamentum flavum—encroachment into the spinal canal.
• Degenerative spondyloarthropathy—causing central, lateral recess, and foraminal stenosis.
• In some patients: congenitally narrow spinal canal, which becomes clinically significant with superimposed degeneration.

The result is mechanical compression, venous congestion, and ischemia of the nerve roots and dural sac, producing the classic syndrome of neurogenic claudication.

What is spondylolisthesis and what types exist?

Not all vertebral slippage is the same. The type of spondylolisthesis largely determines the therapeutic strategy.

Most common types:

• Degenerative spondylolisthesis—most frequent in older adults, typically at L4–L5. It results from degeneration of the disc and facet joints, leading to gradual anterior slippage, often with associated stenosis.
• Isthmic spondylolisthesis—caused by spondylolysis (pars interarticularis defect), commonly at L5–S1. Typical in younger individuals and athletes exposed to hyperextension. It may progress from low-grade to high-grade slippage.
• Dysplastic/congenital—rarer, associated with pelvic and sacral anomalies, more common in children and adolescents.
• Traumatic or pathologic—uncommon, due to acute fracture, tumors, or infection.

The degree of slippage is often classified using the Meyerding grading system (Grades I–IV). Low-grade (I–II) cases are frequently managed conservatively. High-grade slips, particularly in younger patients, carry a higher risk of progression and more often require surgical stabilization.

How do they present: symptoms, neurogenic claudication & radicular pain?

Clinical presentation depends on whether stenosis, slippage, or their combination predominates.

Typical symptoms of lumbar spinal stenosis

• Low back pain, often chronic and mechanical in nature.
• Leg pain, numbness, or heaviness during walking (neurogenic claudication), which improves with sitting or forward flexion (e.g., leaning on a shopping cart).
• Weakness in the lower extremities in advanced stages.
• Less commonly: balance problems, a sense of fatigue, or calf cramping.

Symptoms of spondylolisthesis

• Low back pain, worsened by extension or prolonged standing.
• Sciatica / radiculopathy—leg pain due to nerve root compression within the foramen.
• In younger patients: back pain with tight hamstrings.
• Less commonly: knee-flexed gait or hyperlordosis.

Severe symptoms such as urinary or fecal incontinence, saddle anesthesia, or progressive weakness may indicate cauda equina syndrome or high-grade compression and require urgent neurosurgical evaluation.

What is the natural history—when does the condition worsen?

Symptom progression varies among patients. In some, symptoms remain stable, while in others they gradually worsen and significantly impair daily life.

Lumbar spinal stenosis

• Often shows gradual progression over years as degeneration continues.
• Many patients adapt by limiting activity and reducing walking distances.
• In a substantial proportion, quality of life declines over time without intervention.

Spondylolisthesis

• Low-grade degenerative spondylolisthesis often remains relatively stable in adults, with mild to moderate symptoms manageable conservatively.
• Isthmic and high-grade spondylolisthesis, particularly in children and adolescents, carries a higher risk of progressive deterioration and more often requires surgical intervention.

Patients with established neurological deficits (severe claudication, significant radicular weakness, bladder/bowel dysfunction) have a high likelihood of further decline if the underlying compression is not addressed.

How is the diagnosis made (MRI, CT, dynamic X-rays)?

Diagnosis is based on a thorough clinical examination and targeted imaging.

Typical diagnostic work-up:

• Lumbar MRI—the imaging modality of choice for:
  • visualizing stenosis (central, lateral recess, foraminal),
  • assessing discs, facet joints, ligamentum flavum,
  • identifying nerve root or cauda equina compression.
• CT or CT myelography—useful:
  • in patients with metal implants causing MRI artifacts,
  • for detailed evaluation of bony anatomy, osteophytes, pars defects.
• Standing plain radiographs (AP & lateral):
  • to assess alignment, lordosis, associated deformities (e.g., scoliosis),
  • to quantify the degree of spondylolisthesis.
• Dynamic flexion–extension radiographs—to detect instability (mobile spondylolisthesis).
• Electrodiagnostic testing (EMG/NCS)—in selected cases, to distinguish radiculopathy from peripheral neuropathy.

Importantly, management decisions are always based on the integration of clinical symptoms with imaging findings.

When is conservative treatment sufficient & what does it include?

Not all patients require surgery. In many cases, a well-structured conservative approach can effectively control symptoms.

We initially favor non-operative management when:

• there are no severe neurological deficits or cauda equina syndrome,
• pain is tolerable and responsive to medication/therapy,
• symptom duration is relatively short,
• patients have significant medical comorbidities increasing surgical risk.

Conservative measures include:

• Pharmacologic therapy—analgesics, anti-inflammatory drugs, muscle relaxants, and neuropathic agents when indicated.
• Physical therapy—core strengthening, stretching, posture training, and progressive walking programs.
• Activity modification—avoiding prolonged standing and heavy lifting, incorporating regular rest periods.
• Short-term bracing in acute phases or in adolescents with spondylolysis—avoiding long-term immobilization in adults to prevent deconditioning.
• Epidural injections—for selected cases of severe radicular pain to provide temporary relief.

The goal is to restore acceptable daily function. If optimal conservative care fails to provide meaningful improvement, surgical options are then discussed.

When is surgery indicated for spinal stenosis?

Surgical decisions are primarily driven by quality of life and the presence of neurological symptoms.

General indications for decompressive surgery include:

• Refractory neurogenic claudication with severe limitation of walking despite adequate conservative treatment.
• Progressive neurological deficit (weakness, foot drop, severe radicular pain).
• Cauda equina syndrome or bowel/bladder dysfunction—an emergency indication.
• Severe chronic pain that significantly compromises daily life despite comprehensive non-operative care.

The fundamental principle is neural decompression while preserving spinal stability. Whenever feasible, microsurgical and minimally invasive techniques are employed to reduce postoperative pain and accelerate recovery.

When is surgery needed for spondylolisthesis & what procedures are performed?

In spondylolisthesis, beyond decompression, stabilization is central and, in selected cases, partial reduction of the slip may be indicated.

Indications for surgical management of spondylolisthesis:

• Neurological deficits (radicular weakness, severe radiculopathy, claudication, cauda equina syndrome).
• Progressive slippage (especially in children/adolescents or high-grade slips).
• Significant kyphotic or coronal deformity affecting balance and load distribution.
• Chronic refractory back and/or leg pain with documented instability.

Surgical principles & techniques:

• Decompression—relief of neural compression (laminectomy, foraminotomy). In stable, low-grade degenerative slips, selected cases may require decompression alone, though fusion is often preferred.
• Instrumented fusion—posterior (PLF/PLIF/TLIF) and/or anterior/lateral approaches using screws and rods for stabilization and arthrodesis of the affected segment.
• Partial reduction—in high-grade slips, to improve alignment and foraminal dimensions without undue neurological risk.
• Direct pars repair—in young patients with recent spondylolysis and predominant back pain, without major slippage.

Final technique selection depends on age, type and grade of slip, overall alignment, symptoms, and comorbidities.

Risks, complications & postoperative recovery

Every spinal operation carries inherent risks, but also a substantial potential to improve function and quality of life when indications are appropriate.

Potential complications (general)

• Infection, bleeding, thrombosis—risks of any major surgery.
• CSF leak—more likely in extensive decompressions.
• Neurological deterioration—rare but serious.
• Incomplete symptom relief or late recurrence.
• In fusion: non-union (pseudarthrosis), adjacent segment degeneration.

Recovery & expectations

• After minimally invasive decompression, mobilization often begins the same or next day.
• Leg pain typically improves within days; low back pain resolves more gradually.
• After fusion, complete bony healing requires several months; activity is tailored accordingly.
• Structured physical therapy and weight management significantly enhance long-term outcomes.

At Neuroknife, our objective is transparent counseling regarding benefits and risks, selection of the least invasive effective option, and close postoperative follow-up.