Clinical Findings

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  A 63-year-old man presented with left buttock pain and pain in the L3 dermatome having lasted for 5 months.

  
  
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  The patient exhibited a limping gait.

  
  
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  MRI views showed a herniated disk at the right side of the L3-L4 extraforamen ( Fig. 18.46A,B ).

  
  
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  A CT scan revealed a soft disk fragment ( Fig. 18.46C ).

Preoperative Plan

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  The skin entry point is selected by drawing various lines as shown in Fig. 18.47 , and the distance from midline is ~10.2 cm.

  
  
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  A parallel approach to the upper end plate of the lower vertebra is chosen.

Surgical Procedure

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  The final needle position is at the medial pedicular line in the AP fluoroscopic view and at the posterior body margin in the lateral fluoroscopic view ( Fig. 18.48 ).

  
  
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  A diskographic procedure is done after the needle is placed and before the dilator is inserted ( Fig. 18.49 ).

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  The final position of the working channel is at the midpedicular line in the AP view and at the posterior body margin in the lateral view ( Fig. 18.50 ).

  
  
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  The working channel is angled cranially to reach and remove the foraminal disk fragment ( Fig. 18.51 ).