What is anterolisthesis?

Anterolisthesis: Definition, Causes, and Management

Anterolisthesis is a spinal condition characterized by the forward slippage of a vertebra relative to the vertebra below it. 1 This forward displacement can lead to various symptoms including pain, neurological complications, and functional limitations depending on the severity of the slippage.

Anatomical Understanding

• Anterolisthesis is often described in terms of the direction of slippage (anterior/forward) and the affected vertebrae, such as L5-S1 anterolisthesis, which indicates slippage between the fifth lumbar vertebra and the sacral bone 1
• The condition results in significant deformation and volume changes of the spinal canal due to the vertebral slippage 2
• Spinal canal volume is strongly affected by posterior disc height and the percentage of slippage, with greater slippage correlating with reduced canal volume 2

Causes and Risk Factors

• Anterolisthesis can result from various factors including:
  • Degenerative processes (most common in older adults) 3
  • Traumatic injuries (such as pedicle avulsion) 4
  • Congenital abnormalities 1
• The prevalence of anterolisthesis increases with age and has been found to be two to three times greater in older African American women compared to white women of similar age 5
• Multilevel anterolisthesis can occur but is rare and typically secondary to degenerative processes or severe trauma 4

Clinical Presentation

• Common symptoms associated with anterolisthesis include:
  • Lower back pain that may radiate to the lower limbs 1
  • Neurogenic claudication (pain with walking that improves with rest) 3
  • Muscle tightness and spinal stiffness 1
  • Altered gait patterns and difficulty maintaining stable posture 1
• Symptoms may be relieved in supine and flexion positions due to increased spinal canal volume in these postures 2
• Neurological symptoms can occur if the slippage compresses nearby nerves, potentially leading to radiculopathy 3, 1

Diagnostic Approach

• Diagnosis typically involves:
  • Radiographic evaluation including standing neutral radiographs to measure the degree of anterolisthesis, disc space height, and slip angle 6
  • Dynamic lateral flexion-extension images to identify subtle forms of spinal hypermobility 3
  • Advanced imaging such as CT or MRI to evaluate the spinal canal volume and assess for nerve compression 2

Management Options

Non-surgical Management

• Physiotherapeutic rehabilitation plays a crucial role in:
  • Reducing pain and improving range of motion 1
  • Strengthening muscles to provide better spinal support 1
  • Improving overall quality of life and functional capacity 1

Surgical Management

• Surgical intervention is recommended for symptomatic stenosis associated with degenerative spondylolisthesis when patients desire surgical treatment 3
• Decompression with fusion is the recommended surgical approach for patients with anterolisthesis causing symptomatic stenosis 3
• Surgical techniques include:
  • Decompressive procedures such as laminectomy or laminotomy with judicious use of partial medial facetectomies 3
  • Posterolateral fusion (PLF) following decompression to prevent progressive instability 3
  • Transforaminal lumbar interbody fusion (TLIF) with pedicle screw instrumentation can restore disc height and reduce forward translation 6

Important Considerations and Potential Complications

• Extensive decompression without fusion may lead to iatrogenic destabilization and increased risk of progressive slippage 3
• The reported incidence of progressive slippage after decompression ranges from 9% in patients without preoperative instability to 73% in those with preoperative evidence of spondylolisthesis 3
• Potential surgical complications include:
  • Nerve root injury 7
  • Dural tears 7
  • Infection 7
  • Progressive instability if fusion is not performed 3

Treatment Decision-Making

• Pedicle screw fixation should be considered in patients with:
  • Kyphosis associated with spondylolisthesis 3
  • Excessive motion at the site of degenerative spondylolisthesis 3
• The SPORT studies demonstrated superior outcomes with surgical intervention compared to non-surgical treatment for stenosis with spondylolisthesis for at least 4 years following treatment 3, 7