Endoscopic hook blade and use thereof

Abstract

An endoscopic surgical blade is disclosed. The blade is of a hook design, having an upper cutting surface located on the trailing edge of an arm and a lower cutting surface on the upper edge of the main body of the blade. The blade is part of an endoscopic knife assembly which also contains a knife tube and alignment ring. The endoscopic knife assembly is for use in endoscopic surgery by insertion of the assembly through a slotted cannula. The knife tube is hollow and allows the insertion of an endoscope for viewing of the surgical procedure. A method for a performing an operative procedure on a target tissue in a subject using an endoscopic knife assembly having a hook blade is also described.

1 - 20 . (canceled) 
     
     
         21 . A method for a performing a operative procedure on a target tissue in a subject, comprising:
 establishing an entry portal,   inserting a cannula having open proximal and distal ends,   inserting an endoscope into the cannula, said endoscope comprising an endoscopic knife assembly having a hook blade,   advancing said endoscope so that the hook blade moves distal to and is in contact with the target tissue, and   operatively engaging the target tissue with the hook blade,   wherein the hook blade comprises:
 an arm having a forward edge, a trailing edge and an upper cutting surface located on the trailing edge; 
 a main body having an upper edge, a lower edge, a distal section, a proximal section, and a lower cutting surface located on the upper edge of the distal section; 
 wherein the distal section of the main body angles downward from the proximal section of the main body, forming a downward angle with the proximate section of the main body, 
 wherein the arm protrudes from the distal section of the main body and extends back towards the main body in a hook-like manner, forming a hook angle with the proximal section of the main body, and 
 wherein the upper cutting surface and the lower cutting surface meets at a crotch forming a cutting angle between the two cutting surfaces. 
   
     
     
         22 . The method of  claim 21 , wherein said operative procedure is an endoscopic surgical procedure selected from the group consisting of carpal tunnel release, cubital tunnel release, plantar fascia release, lateral release for patella realignment, release of the extensor tendons, release of the posterior and other compartments of the leg, and forearm fascial release. 
     
     
         23 . The method of  claim 21 , wherein said method further comprises a step of withdrawing the hook blade back towards the cannula to perform the operative procedure on the target tissue. 
     
     
         24 . The method of  claim 21 , wherein said cannula comprises an open slot extending along the length of the cannula. 
     
     
         25 . The method of  claim 21 , wherein said inserting of said endoscope comprising an endoscopic knife assembly having a hook blade is preceded by the insertion of another endoscope comprising a means for visualization of the target tissue. 
     
     
         26 . The method of  claim 25 , wherein said cannula is a clear cannula. 
     
     
         27 . The method of  claim 26 , further comprising visualization of anatomic structures surrounding the cannula. 
     
     
         28 . The method of  claim 21 , wherein said establishing an entry portal comprises making an incision. 
     
     
         29 . The method of  claim 21 , wherein the hook angle of the hook blade is between about 55 degrees and about 75 degrees. 
     
     
         30 . The method of  claim 29 , wherein the hook angle is about 65 degrees. 
     
     
         31 . The method of  claim 21 , wherein the cutting angle of the hook blade is between about 40 degrees and about 60 degrees. 
     
     
         32 . The method of  claim 31 , wherein the cutting angle is about 50 degrees. 
     
     
         33 . The method of  claim 21 , wherein the downward angle of the hook blade is between about 150 degrees and about 175 degrees. 
     
     
         34 . The method of  claim 33 , wherein the downward angle is between about 165 degrees. 
     
     
         35 . The method of  claim 21 , wherein the proximal section of the main body of the hook blade has a tapered end. 
     
     
         36 . The method of  claim 21 , wherein the main body of the hook blade comprises a notch on the lower edge to engage with a knife tube. 
     
     
         37 . The method of  claim 21 , wherein the arm comprises an upper radius on the upper end of the forward edge to prevent the forward edge from damaging tissue as the hook blade is advanced from a cannula. 
     
     
         38 . The method of  claim 37 , wherein the arm of the hook blade further comprises a lower radius on the lower end of the forward edge to prevent the forward edge from damaging tissue as the hook blade is advanced from a cannula. 
     
     
         39 . The method of  claim 21 , wherein the hook blade has a total vertical height in the range of about 4 mm to about 5 mm.