21.1 Case Presentation and Preoperative Imaging

A 35-year-old woman presents to the office with long-standing axial low back pain. The pain radiates to the bilateral lower extremities, including the right posterior thigh, right lateral calf, and left posterior thigh. Pain is persistent at baseline, but worsens with ambulation and changes in temperature. She denies any trauma or recent infections. Conservative therapy with physical therapy, narcotics, and muscle relaxants provided minimal pain relief. Lumbar magnetic resonance imaging (MRI) was obtained ( Fig. 21.1 ).

21.2 Indications

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  Spondylolisthesis (grade I or II).

  
  
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  Degenerative disk disease.

  
  
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  Postdiskectomy collapse with neuroforaminal stenosis.

  
  
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  Revision of posterior pseudoarthrosis or postlaminectomy kyphosis.

  
  
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  Coronal and/or sagittal imbalance.

21.3 Position

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  Supine.

  
  
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  Landmarks:

  
  
  
  
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    Umbilicus: opposite the L3–L4 disk space.

    
    
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    Pubic symphysis: pubic tubercle is located lateral to the midline.

21.4 Approach

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  Superficial dissection:

  
  
  
  
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    Skin incision is midline, located between the umbilicus and pubic symphysis ( Fig. 21.2 ):

    
    
    
    
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      The internervous plane is in the midline, as the abdominal musculature is innervated segmentally by the 7th to 12th intercostal nerves.

    
    
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    Musculus rectus abdominis fascia incised and the muscle belly is mobilized.

    
    
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    The rectus sheath is then incised → exposes the retroperitoneum.

  
  
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  Deep dissection:

  
  
  
  
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    Retroperitoneum is swept laterally and retractors are placed when the psoas is encountered ( Fig. 21.3 ):

    
    
    
    
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      Care must be taken to avoid nerve injury to the adjacent presacral plexus or iliolumbar artery, depending on level of pathology.

      
      
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      Identify and ligate the middle sacral artery to prevent hemorrhage.

      
      
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      Visceral injury to the great vessels or ureters can occur. Identify and retract these structures out of the operative field.

    
    
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    Soft tissues in front of the disk space are retracted medially.

    
    
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    Bluntly dissect and clear off the disk space.

    
    
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    Perform annulotomy and remove disk fragments.

    
    
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    Prepare end plates.