Clinical Findings

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  A patient presented with right thigh pain and walking difficulty for 3 months.

  
  
• 
  

  Paresthesia on the right L3 dermatome was checked.

  
  
• 
  

  Sagittal and axial MRI and CT scan showed a central to right paramedian soft disk herniation at the L2-L3 level ( Fig. 18.18 ).

Preoperative Plan

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  For a herniated disk at the upper lumbar level, the target point is preferably kept at the midpedicular line or the lateral pedicular line to avoid neural injury because the dural sac lies more medially due to the narrow width of the pedicles at this level.

  
  
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  The skin entry point is selected by drawing various lines as shown in the axial MRI scan, and the distance from midline is ~8.5 cm ( Fig. 18.18D )

Surgical Procedures

1. 
   

   Diskography is performed, and the epidural leakage of dye through annular fissure is observed, which implies the noncontained nature of the disk herniation ( Fig. 18.19A ).

   
   
2. 
   

   Even though the annular puncture site is kept at the midpedicular line, the tip of the working cannula can be advanced further once it pierces the posterior annulus ( Fig. 18.19B ).

   
   
3. 
   

   The working cannula is positioned within the posterior annulus ( Fig. 18.19C ).

• 
  

  The proper position of the grasping forceps is checked frequently with the fluoroscope to avoid damage to the contralateral nerve root ( Fig. 18.19D ).