What is spondylolisthesis?

Spondylolisthesis: Definition, Diagnosis, and Management

Spondylolisthesis is a spinal condition characterized by the forward displacement of one vertebra over the vertebra below it, most commonly affecting the lower lumbar spine, particularly at L5-S1 and L4-L5 levels. 1 This condition can cause back pain, radiculopathy, and in severe cases, neurogenic claudication.

Types of Spondylolisthesis

• Isthmic spondylolisthesis: Results from a defect in the pars interarticularis, typically at L5-S1 level 2
• Degenerative spondylolisthesis: Occurs due to remodeling of facet joints, most commonly at L4-L5 level in women over 40 years 2
• Other types: Include dysplastic, traumatic, and pathological spondylolisthesis

Classification by Severity

Spondylolisthesis is graded based on the percentage of vertebral body displacement:

• Grade I: 0-25% slippage
• Grade II: 25-50% slippage
• Grade III: 50-75% slippage
• Grade IV: >75% slippage

Diagnostic Imaging

For suspected spondylolisthesis, the appropriate imaging includes:

• Initial imaging: Radiography of the symptomatic region is the recommended first-line imaging modality (rated 9/9 in appropriateness) 3
• Advanced imaging:
  • MRI spine without IV contrast is recommended for additional evaluation (rated 7/9) when radiographs are positive or symptoms persist 3
  • CT spine without IV contrast may be useful to evaluate bony lesions (rated 6/9) 3
  • Technetium-99m bone scan with SPECT may be an alternative to MRI for diagnosis and characterization of spondylolysis spectrum 3

Clinical Presentation

Common symptoms include:

• Low back pain, often worsening with activity and improving with rest
• Radicular pain in the lower extremities
• Neurogenic claudication (in cases with spinal stenosis)
• Hamstring tightness
• Altered gait pattern
• Potential neurological deficits in severe cases

Management Approach

Non-Surgical Management (First-Line Treatment)

Non-surgical management is the first-line approach for low-grade spondylolisthesis (Grade I-II) 1:

1. Physical therapy:

   • Flexion-based exercises have shown better outcomes than extension exercises for symptomatic spondylolisthesis 2
   • Strengthening of abdominal and paraspinal muscles 2
   • Activity modification and instruction in proper body mechanics

2. Pain management:

   • NSAIDs are recommended as first-line medications if there are no contraindications 4
   • Acetaminophen can be considered as a safe alternative 4
   • Epidural steroid injections may provide temporary relief 5

3. Supportive measures:

   • Antilordotic orthoses/bracing in selected cases 2
   • Job modifications to avoid activities that exacerbate symptoms

4. Duration of conservative treatment:

   • A minimum trial period of 3-4 months is recommended before considering surgical options 2
   • More than 80% of children treated non-surgically experience resolution of symptoms 6

Surgical Management

Surgery should be considered in the following circumstances:

• Progressive neurological deficits
• Cauda equina syndrome
• Intractable pain despite adequate conservative management
• Persistent symptoms after 6-12 weeks of conservative treatment 4
• High-grade slippage (Grade III-IV)

Surgical options include:

1. Decompression: To relieve nerve compression
2. Fusion: To stabilize the spine
   • Posterior lumbar interbody fusion (PLIF)
   • Transforaminal lumbar interbody fusion (TLIF)
   • Minimally invasive surgical techniques

Special Considerations

• Elderly patients: Higher risk of medication side effects; require more careful progression of exercise intensity 4
• Children and adolescents: Better response to conservative management; different surgical approaches may be considered 6
• High-grade spondylolisthesis: More likely to require surgical intervention

Monitoring and Follow-up

• Regular reassessment of pain and function
• Adjustment of treatment plan based on response
• Monitoring for progression of slippage
• For surgically treated patients, long-term follow-up to monitor for complications such as adjacent segment disease or pseudarthrosis 1

Prognosis

• Most patients with low-grade spondylolisthesis respond well to conservative management
• Approximately 15% of individuals with pars interarticularis lesions (spondylolysis) progress to spondylolisthesis 6
• Surgical outcomes are generally favorable for appropriately selected patients

By understanding the nature of spondylolisthesis and implementing appropriate management strategies, most patients can achieve significant symptom relief and improved quality of life.