Clinical Findings

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  A 49-year-old man presented with radiating pain of the right leg having lasted for 10 weeks.

  
  
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  Hypoesthesia on the right S1 dermatome was observed.

  
  
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  Preoperative sagittal and axial MRI views showed a herniation on the right side of the L5-S1 level. A preoperative CT showed a soft disk ( Fig. 18.96 ).

Preoperative Plan

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  The safe space for needle insertion in this case is at the shoulder region of the S1 nerve root. The intended trajectory and target point for insertion of the needle are shown in Fig. 18.97 .

  
  
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  In addition, another factor favoring a shoulder approach is the medial displacement of the S1 nerve root by the herniated disk because the origin site of the S1 nerve root is beyond the disk space.

Surgical Procedures

1. 
   

   Diskography aids in the procedure by staining the herniated nuclear fragments blue ( Fig. 18.98A ).

   
   
2. 
   

   The needle tip is close to the medial aspect of the facet joint ( Fig. 18.98B ).

   
   
3. 
   

   The working cannula is placed at a slight upward angle over the disk space, and the forceps tip is inside the disk space ( Fig. 18.98C ).

   
   
4. 
   

   The working cannula is in the shoulder position as seen in Fig. 18.98D.

Endoscopic Findings

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  The LF and the disk fragment are seen immediately after the insertion of the endoscope. In such large herniations, the first endoscopic view is usually the blue-stained herniated disk ( Fig. 18.99A ).

  
  
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  The endoscopic forceps are used to grasp the disk fragment ( Fig. 18.99B ).

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  After removing the extruded disk with the pituitary forceps, the side-firing Ho:YAG laser is used to ablate the PLL ( Fig. 18.99C ).

  
  
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  The herniated fragments are completely removed, leaving the S1 nerve root and the disk space decompressed ( Fig. 18.99D ).

  
  
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  After retracting the cannula slightly, the S1 nerve root and epidural fat can be visualized ( Fig. 18.99E ).

  
  
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  After further retracting the cannula, the LF, epidural fat, and S1 nerve root are observed ( Fig. 18.99F ).