Methods and instrumentation for positioning implants in spinal disc space in an anterior lateral approach

Abstract

Instruments and methods are provided for positioning one or more implants into a spinal disc space. The instruments and methods have application in an anterior lateral approach to the disc space between the L4 and L5 vertebrae. The instruments include a distractor, a housing, a guide member to facilitate positioning of the housing, and a partition member engageable to the housing to facilitate positioning of one or more implants into the disc space.

1 . A surgical instrument insertable in a spinal disc space between an upper vertebra and a lower vertebra, comprising:
 a head including an upper surface positionable adjacent an endplate of the upper vertebra and an opposite lower surface positionable adjacent an endplate of the lower vertebra; and   a shaft extending proximally from said head, said shaft including a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including a guide portion adjacent said head and engageable to guide an instrument therealong to the spinal disc space, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion and transversely oriented thereto.   
     
     
         2 . The instrument of  claim 1 , wherein said proximal portion extends along a second axis generally parallel to said first axis. 
     
     
         3 . The instrument of  claim 2 , wherein said proximal portion includes a handle oriented transversely to said second axis. 
     
     
         4 . The instrument of  claim 2 , wherein said offset portion extends along a third axis oriented at an angle to said first axis. 
     
     
         5 . The instrument of  claim 1 , wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion. 
     
     
         6 . A surgical instrument for spinal surgery having an operative orientation including an anterior lateral approach to a spinal disc space between L4 and L5 vertebrae of a patient, comprising:
 a distal end portion positionable adjacent the spinal disc space and a proximal portion offset from said distal portion to avoid an iliac crest of the patient when the surgical instrument is the operative orientation.   
     
     
         7 . The instrument of  claim 6 , wherein the instrument is a distractor including a head at said distal portion positionable in the spinal disc space and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset anteriorly of the iliac crest in the operative orientation. 
     
     
         8 . The instrument of  claim 6 , wherein the instrument is a guide instrument including a guide member at said distal portion and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset cephaladly of the iliac crest in the operative orientation. 
     
     
         9 . A surgical instrument assembly for providing access to a spinal disc space, comprising:
 a distractor including a head positionable in a spinal disc space and a shaft extending proximally from said head, said shaft including a guide portion along at least a portion thereof adjacent said head;   a housing including an opening therethrough for providing access to the spinal disc space when positioned adjacent thereto; and   a guide instrument including a shaft and a guide member at a distal end of said shaft, said guide member removably engaged to said housing, said guide member moveable along said guide portion of said distractor with said shaft of said guide instrument in side-by-side relation to said shaft of said distractor to guide said housing along said distractor to the spinal disc space when said head is positioned in the spinal disc space.   
     
     
         10 . The assembly of  claim 9 , wherein said housing includes a frame portion defining said opening therethrough, said housing further including a first extension along one side of said opening extending distally from said frame portion and a second extension along an opposite side of said opening extending distally from said frame portion, said first and second extensions positionable in the spinal disc space to maintain a disc space distraction when said head is removed from the spinal disc space. 
     
     
         11 . The assembly of  claim 10 , wherein said first extension is longer than said second extension. 
     
     
         12 . The assembly of  claim 10 , wherein said frame portion includes an upper wall positionable adjacent an upper vertebra and a lower wall positionable adjacent a lower vertebra, said upper and lower walls each including a distal end curvature corresponding to a curvature of a lateral profile of the upper and lower vertebrae, respectively. 
     
     
         13 . The assembly of  claim 9 , wherein said opening includes a rectangular shape. 
     
     
         14 . The assembly of  claim 9 , wherein said guide member includes a distal portion positionable in said opening to engage said guide member in said opening and a proximal portion forming a lip around said distal portion, said lip in abutting engagement with a proximal end of said housing when said distal portion is positioned in said opening. 
     
     
         15 . The assembly of  claim 14 , wherein said housing includes a proximally-opening notch in a wall thereof and said guide member includes a protrusion positionable in said notch. 
     
     
         16 . The assembly of  claim 9 , wherein said guide member includes a passage extending between a distal end and a proximal end of said guide member and said guide portion of said distractor is movably received in said passage. 
     
     
         17 . The assembly of  claim 16 , wherein said guide member includes tapered surfaces forming an opening into said passage along one side thereof. 
     
     
         18 . The assembly of  claim 16 , wherein said passage extends along a center of said guide member and said shaft of said guide instrument is offset from said passage. 
     
     
         19 . The assembly of  claim 18 , wherein said shaft of said guide instrument includes a distal portion, a proximal portion, and an offset portion therebetween, said offset portion positioning said proximal portion cephaladly of said distal portion in an operative orientation of said guide instrument. 
     
     
         20 . The assembly of  claim 18 , wherein said shaft is offset posteriorly of said passage in said operative orientation of said guide instrument. 
     
     
         21 . The assembly of  claim 9 , wherein said shaft of said distractor includes a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including said guide portion, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion along a second axis oriented at a first angle relative to said first axis. 
     
     
         22 . The assembly of  claim 21 , wherein said proximal portion extends along a third axis generally parallel to said first axis. 
     
     
         23 . The instrument of  claim 22 , wherein said proximal portion includes a handle oriented transversely to said third axis. 
     
     
         24 . The instrument of  claim 21 , wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion. 
     
     
         25 - 56 . (canceled)