RF intervertebral disc surgical system

Abstract

A spinal surgical system comprising a plurality of surgical components for cooperating with a electrosurgical handpiece comprising an elongated tubular member housing an electrode, with the tubular member configured to fit within and be extended down a standard sized cannula in a MIS procedure. The system components comprise one or more cannulas, straight or beveled; one or more guide wires, with and without pointed ends for piercing tissue; a tapered dilator; a trephine; and one or more depth control stops for mounting on the cannula for monitoring its depth. The system is especially useful for performing a discectomy.

1 . A MIS intervertebral disc surgical system for use with an electrosurgical instrument having an elongated tubular member housing an electrosurgical electrode for excising of or shrinking tissue, comprising:
 (a) one or more straight or beveled cannulas, the cannulas configured with a lumen to receive the elongated tubular member of the electrosurgical instrument,   (b) one or more guide wires, at least one of the guide wires having a pointed end for piercing tissue, each of the guide wires being configured to fit within the cannula's lumen,   (c) a tapered dilator configured to slide over a guide wire,   (d) a trephine configured to slide over a guide wire,   (e) an adjustable depth control stop for mounting on the cannula for monitoring its depth into the tissue.   
   
   
       2 . A disc surgical system as claimed in  claim 1 , wherein the cannula has an enlarged head at one end, the enlarged head having an internally threaded opening. 
   
   
       3 . A disc surgical system as claimed in  claim 2 , wherein the dilator has an enlarged head at one end, the enlarged head having an externally threaded extension configured to threadingly engage the internally threaded opening on the cannula's head. 
   
   
       4 . A disc surgical system as claimed in  claim 1 , wherein the depth control stop comprises two threaded members that when tightened lock to the cannula. 
   
   
       5 . A disc surgical system as claimed in  claim 1 , wherein the dilator has a length such that, when fully engaging the cannula's lumen, the dilator's end protrudes about 3-5 mm from the end of the cannula. 
   
   
       6 . A disc surgical system as claimed in  claim 1 , wherein the trephine has a length such that, when fully engaging the cannula's lumen, the trephine's end protrudes up to about 10 mm from the end of the cannula. 
   
   
       7 . A disc surgical system as claimed in  claim 1 , wherein the dilator has a tapered end. 
   
   
       8 . A disc surgical system as claimed in  claim 1 , wherein the trephine has a cutting end. 
   
   
       9 . A spinal procedure comprising the steps:
 a. providing a cannula, a guide wire, a tapered dilator with a lumen, a trephine with a lumen, a depth control stop, and an elongated electrosurgical instrument,   b. after a spinal needle with a lumen is inserted into a patient's back toward a spinal disc, the guide wire is threaded through the needle lumen into the disc nucleus,   c. the spinal needle is then removed leaving the guide wire in place,   d. the cannula and dilator joined together are placed over the guide wire and advanced toward the annulus,   e. the cannula with dilator is advanced under fluoroscopic guidance into the nucleus,   f. the dilator is removed creating a portal into the disc,   g. the depth stop is mounted on the cannula and advanced to the patient's skin and secured to prevent advancement of the cannula,   h, the electrosurgical instrument is advanced through the cannula and into the pulpous to remove, shrink or modulate pulpous tissue.   
   
   
       10 . A procedure as set forth in  claim 9 , further comprising:
 i. after step d. and before step e., the dilator is removed from the cannula,   j. the trephine is inserted through the cannula and advanced toward the outer surface of the disc annulus and an annulotomy is created by rotation of the trephine 1-3 turns,   k. the trephine is removed and replaced by the dilator.   
   
   
       11 . The procedure of  claim 10 , wherein the electrosurgical instrument is activated with high frequency currents at a frequency of about 4 MHz.