Clinical Findings

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  A 31-year-old male presented with predominant right lower anterior thigh pain and low back pain having lasted for 2 months.

  
  
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  The patient exhibited weakness of the right quadriceps and diminished right knee jerk.

  
  
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  MRI sagittal view shows a herniated L3-L4 disk and a central to right paramedian ruptured disk fragment is seen on axial views. CT scan reveals a soft disk ( Fig. 18.32A–C ).

Preoperative Planning

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   The hypertrophied anterior surface of the superior facet may interfere with adequate visualization and proper positioning of the working instruments; thus it is necessary to use an endoscopic drill to shave off the overhanging bone in this case.

   
   
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   The skin entry point is selected by drawing various lines as shown in the axial MRI, and the distance from midline is ~12.5 cm and 5 degrees cranial to caudal direction ( Fig. 18.32D ).

Surgical Procedures

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  On the AP view, the needle tip is located at midline, whereas in the lateral view it is located on the posterior one fifth of the vertebral body ( Fig. 18.33 ).

Endoscopic Findings

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  The facet joint capsule along with the superior facet blocks the endoscopic view ( Fig. 18.34A ).

  
  
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  The endoscopic drill is used to remove the overhanging facet bone for a better view ( Fig. 18.34B ).

  
  
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  After the bone has been drilled, a part of the herniated disk fragment along with LF and the drilled undersur-face of the facet can be observed ( Fig. 18.34C ).

  
  
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  The mobilized herniated fragment is seen ( Fig. 18.34D ).

  
  
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  On further advancement of the cannula, the blue-stained hernia fragment is now clearly visualized going into the epidural space through the fibers of the PLL ( Fig. 18.34E ).

  
  
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  After mobilization, the herniated disk fragment is removed with an endoscopic grasping forceps ( Fig. 18.34F ).

  
  
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  After complete removal of the blue-stained herniated nucleus, the decompressed TNR is seen from the 12 o’clock to 9 o’clock position ( Fig. 18.34G ).