Methods and instrumentation for vertebral interbody fusion

Abstract

A method and instrumentation particularly adapted for disc space preparation from an anterior approach to the spine. The invention provides an improved guide sleeve defining a channel having overlapping cylindrical working channel portions and lateral non-distracting extensions extending from reduced thickness wall portions. The guide sleeve has an overall reduced width configuration adjacent the distal end due to the overlapping working channel portions and reduced thickness wall portions. A pair of distractors are provided. A first distractor includes a shaft and distal tip, each having convex walls. A second distractor includes a shaft and distal tip including a recessed area at least along the tip. The first distractor is at least partially received within the recessed area of the second distractor when the first and second distractors are in side-by-side relation and a reduced overall width of the distractors is obtained. Preferably, the first and second distractors are used with the guide sleeve. A method of using the disclosed instruments is also provided.

What is claimed is:  
     
         1 . A surgical instrument for distracting a spinal disc space, comprising: 
 a distractor having a length and including: 
 a shaft and a first distractor tip connected to an end of said shaft, including: 
 a first surface and an opposite second surface defining a distraction height; and  
 a recessed area extending between said first and second surfaces along at least a portion of said length.  
 
   
     
     
         2 . The instrument of  claim 1 , wherein said shaft includes a recessed area adjacent to and coplanar with said recessed area of said distractor tip along a portion of a length of said shaft.  
     
     
         3 . The instrument of  claim 2 , wherein said recessed area of said distractor tip and said recessed area of said shaft extend along substantially the entire length of said distractor.  
     
     
         4 . The instrument of  claim 3 , wherein said recessed areas are concave surfaces.  
     
     
         5 . The instrument of  claim 2 , wherein said recessed areas are concave surfaces.  
     
     
         6 . The instrument of  claim 1 , wherein said first surface and said second surface are substantially parallel.  
     
     
         7 . The instrument of  claim 6 , wherein said first surface and said second surface are each substantially planar.  
     
     
         8 . The instrument of  claim 1 , wherein said recessed area is configured to permit rotation of a surgical device positioned adjacent thereto.  
     
     
         9 . The instrument of  claim 1 , wherein said distractor tip is integrally formed with said shaft.  
     
     
         10 . The instrument of  claim 1 , wherein said recessed area is a concave surface extending between said first and second surfaces.  
     
     
         11 . The instrument of  claim 10 , wherein said distractor tip includes a convex surface opposite said concave surface extending between said first and second surfaces.  
     
     
         12 . The instrument of  claim 1 , wherein said distractor tip includes a rounded leading end extending between said first and second surfaces.  
     
     
         13 . The surgical instrument of  claim 1 , further comprising: 
 a second distractor having a second length and including: 
 a second shaft extending along a portion of said second length;  
 a second distractor tip connected to an end of said second shaft, including: 
 a first surface and an opposite second surface defining a second distraction height; and  
 wherein said second distractor is positionable adjacent said distractor with at least a portion of said second distractor being received within said recessed area of said distractor to define an overlap region.  
 
   
     
     
         14 . The instrument of  claim 13 , wherein said second distractor includes a pair of opposite convex surfaces extending between said first surface and said second surface.  
     
     
         15 . The surgical instrument of  claim 13 , wherein said shaft of said distractor includes a recessed area adjacent to and coplanar with said recessed area of said distractor tip along the length of said shaft, and said second shaft of said second distractor is positionable adjacent said distractor shaft with said second distractor shaft at least partially received in said recessed area.  
     
     
         16 . The instrument of  claim 15 , wherein said distractor shaft includes a pair of notches in said recessed area and said second distractor shaft includes a locking member positionable in said pair of notches to lock said first distractor and said second distractor together.  
     
     
         17 . The instrument of  claim 13 , wherein said shaft includes an opening and said second shaft includes a second opening, and further including a clip securable to each of said opening and said second opening to couple said distractor adjacent to said second distractor.  
     
     
         18 . The instrument of  claim 13 , further comprising a driving cap for placement over the other end said distractor and the other end of said second distractor for transmitting a driving force to said instrument during insertion.  
     
     
         19 . A surgical instrument for distracting a spinal disc space, comprising: 
 a first distractor having a first shaft and a first distractor tip extending from said first shaft, said first distractor tip including opposite first and second surfaces defining a first distraction height and including a recessed area extending between said first and second surfaces;    a second distractor having a second shaft and a second distractor tip extending from said second shaft, said second distractor tip including opposite first and second surfaces defining a second distraction height substantially equal to said first distraction height; and    a guide sleeve having a wall defining a working channel, wherein said first and second distractors are received in said working channel of said guide sleeve.    
     
     
         20 . The surgical instrument of  claim 19 , wherein: 
 said first distractor includes a convex surface opposite said recessed area extending between said first and second surfaces of said first distractor tip; and    said second distractor includes a pair of opposite convex surfaces extending between said first and second surfaces of said second distractor tip.    
     
     
         21 . The instrument of  claim 20 , wherein said second distractor is positionable adjacent said first distractor with one of said convex surfaces of said second distractor tip received at least partially in said recessed surface to define an overlap region.  
     
     
         22 . The instrument of  claim 19 , wherein said working channel extends between a proximal working end and a distal end of said guide sleeve.  
     
     
         23 . The instrument of  claim 19 , wherein said distal end of said guide sleeve includes a pair of opposite flanges extending from a distal end of said guide sleeve said wall along each side of said working channel for insertion into a distracted disc space.  
     
     
         24 . The instrument of  claim 23 , further comprising a number of spikes extending from said distal end of said guide sleeve intermediate said pair of flanges for engaging vertebrae on either side of the distracted disc space.  
     
     
         25 . The instrument of  claim 23 , wherein said wall of said guide sleeve includes a reduced thickness portion along each side of said working channel extending from said distal end toward a proximal end of said guide sleeve, whereby said guide sleeve has a first width at said proximal end and a second width at said reduced thickness portions, said first width being greater than said second width.  
     
     
         26 . The instrument of  claim 25 , wherein each of said flanges has a thickness corresponding to said reduced thickness portion.  
     
     
         27 . The instrument of  claim 19 , wherein said guide sleeve includes a visualization window extending proximally from a distal end of said guide sleeve.  
     
     
         28 . The instrument of  claim 19 , wherein said guide sleeve includes a flange ring at said proximal end.  
     
     
         29 . The instrument of  claim 19 , wherein said working channel includes a first working channel portion for receiving said first distractor and a second working channel portion for receiving said second distractor.  
     
     
         30 . The instrument of  claim 29 , wherein said first working channel portion and said second working channel portion form a working channel having a figure eight shape.  
     
     
         31 . The instrument of  claim 29 , wherein each of said first and second working channel portions has a truncated circular shape, wherein said truncated portions are positioned adjacent one another.  
     
     
         32 . A method for distracting a spinal disc space, comprising: 
 gaining access to the disc space;    providing a first distractor having a first distractor tip with a recessed area extending along its length;    providing a second distractor having a second distractor tip;    positioning the second distractor adjacent the first distractor with the second distractor tip at least partially received in the recessed area; and    inserting the distractor tips into the disc space to distract the disc space.    
     
     
         33 . The method of  claim 32 , further comprising: 
 providing a guide sleeve having a working channel extending therethrough between a proximal end and a distal end;    positioning the first and second distractors within the working channel; and    applying a driving force to the first and second distractors and to the guide sleeve to insert the first and second distractor tips into the disc space.    
     
     
         34 . The method of  claim 33 , further comprising: 
 applying a driving force only to the guide sleeve to advance the guide sleeve towards the disc space until the distal end is positioned adjacent the disc space.    
     
     
         35 . The method of  claim 34 , wherein the guide sleeve is provided with a pair of flanges extending from the distal end, the flanges being positioned in the disc space when the distal end is positioned adjacent the disc space.  
     
     
         36 . The method of  claim 34 , wherein the flanges have a height that is not greater a height of the distracted disc space.  
     
     
         37 . The method of  claim 34 , wherein the guide sleeve is provided with a number of spikes extending from the distal end, the number of spikes engaging the vertebral bodies on either side of the disc space when the distal end is positioned adjacent the disc space.  
     
     
         38 . The method of  claim 34 , further comprising: 
 removing the second distractor from the guide sleeve to form a substantially cylindrical working space through the guide sleeve adjacent the first distractor tip.    
     
     
         39 . The method of  claim 38 , further comprising: 
 reaming the disc space adjacent the recessed area of the first distractor tip;    providing a first implant having a concave side surface; and    inserting the first implant into the reamed disc space with the concave side surface facing the first distractor tip.    
     
     
         40 . The method of  claim 39 , further comprising: 
 tapping threads into this reamed disc space before inserting the implant; and    threading the first implant into the tapped disc space.    
     
     
         41 . The method of  claim 39 , further comprising: 
 removing the first distractor from the disc space;    reaming the disc space adjacent the inserted implant; and    inserting a second implant adjacent the inserted implant.    
     
     
         42 . The method of  claim 41 , the inserted second implant has a convex side surface positioned adjacent the concave side surface of the first implant.  
     
     
         43 . The method of  claim 42 , wherein the second implant has a concave side surface facing the concave side surface of the first implant to define a cavity therebetween; and further comprising placing bone growth material within the cavity.  
     
     
         44 . The method of  claim 33 , wherein the guide sleeve includes a flange ring on the proximal end, wherein the driving force to the guide sleeve is applied to the flange ring.  
     
     
         45 . The method of  claim 32 , further comprising: 
 removing the second distractor from the disc space to form a working space adjacent the first distractor tip.    
     
     
         46 . The method of  claim 45 , further comprising: 
 reaming the disc space adjacent the recessed area of the first distractor tip;    providing a first implant having a concave side surface; and    inserting the first implant into the reamed disc space with the concave side surface facing the first distractor tip.    
     
     
         47 . The method of  claim 46 , further comprising: 
 tapping threads into this reamed disc space before inserting the implant; and    threading the first implant into the tapped disc space.    
     
     
         48 . The method of  claim 46 , further comprising: 
 removing the first distractor from the disc space;    reaming the disc space adjacent the inserted implant; and    inserting a second implant adjacent the inserted implant.    
     
     
         49 . The method of  claim 48 , the inserted second implant has a convex side surface positioned adjacent the concave side surface of the first implant.  
     
     
         50 . The method of  claim 49 , wherein the second implant has a concave side surface facing the concave side surface of the first implant to define a cavity therebetween; and further comprising placing bone growth material within the cavity.