Spine distraction implant and method

Abstract

A supplemental spine fixation device and method is used in association with a primary spine fixation device. The supplemental spine fixation device includes a guide and spacer for distracting apart adjacent spinous processes and the device has hook members which hook about the first and second spinous processes. With the spinous processes distracted and the hook members about the spinous processes, the hook members can be rigidly secured to a hub in order to rigidly affix the spinous processes about the spacer. The rigidity between the spinous processes assures that the vertebral bodies will be held rigidly in place in order to promote bone growth and fusion. Further additional freedom of movement between the spacer and hub is accomplished with the spacer being pivotably mounted relative to the hub. The hooks have a tissue distracting lead-in guide for allowing the hooks to be easily urged between spinous processes.

1 . An implant adapted to be inserted between adjacent spinous processes comprising: 
 a body that is adapted to fit between spinous processes;    said body including first and second ends and a middle section;    wherein at least one of said first and second ends has a diameter that is larger than the middle section; and    a plurality of ribs provided at least in said middle section.    
     
     
         2 . The implant of  claim 1  wherein: 
 at least one of said first and second ends is a tissue expander.    
     
     
         3 . The implant of  claim 1  wherein: 
 at least one of said first and second ends is one of rounded and wedge shaped in order to distract the adjacent spinous processes when the implant is inserted between the spinous processes.    
     
     
         4 . The implant of  claim 1  wherein: 
 said ribs extend from the first end to the second end of said body.    
     
     
         5 . The implant of  claim 1  wherein said body is cylindrical and is adapted to pass through a cylindrical cannula.  
     
     
         6 . The implant of  claim 1  wherein a valley is defined between ribs, which valley has a diameter that is smaller than a diameter of one of said first and second ends in order to allow said one of said first and second ends to distract the spinous processes and allow the spinous processes to relax into the valley in order to retain the implant between the spinous processes.  
     
     
         7 . The implant of  claim 1  wherein a valley is defined between ribs, which valley has a diameter that is smaller than a diameter of one of said first and second ends in order to allow said one of said first and second ends to distract the spinous processes and allow the spinous processes to relax into the valley in order to retain the implant between the spinous processes with said first end located on one side of adjacent spinous processes and the second end located on the other side of adjacent spinous processes.  
     
     
         8 . The implant of  claim 1  wherein at least part of said first end can be removed once the implant is located between spinous processes.  
     
     
         9 . The implant of  claim 1  wherein at least some of the adjacent ribs have a larger diameter relative to the next adjacent rib.  
     
     
         10 . An implant adapted to be inserted between adjacent spinous processes comprising: 
 a body that is adapted to fit between spinous processes;    said body including first and second ends and a middle section;    wherein at least one of said first and second ends has a diameter that is larger than the middle section; and    a plurality of ribs provided at least in said middle section; and    wherein at least some of said ribs have a diameter that is larger than the next adjacent rib.    
     
     
         11 . The implant of  claim 10  wherein at least three or more of said ribs have a diameter that is larger than the next adjacent rib and wherein said ribs are positioned with the rib with the smallest diameter located proximal to the first end and the largest diameter at a distal location from said first end.  
     
     
         12 . The implant of  claim 10  wherein said ribs include at least a first rib, a second rib and a third rib, and wherein the diameter of the first rib is smaller than the diameter of the second rib and the diameter of the second rib is smaller than the diameter of the third rib and the second rib is located between the first rib and the second rib.  
     
     
         13 . The implant of  claim 1  in combination with a kit that includes a cannula through which the implant can pass, said cannula adapted to be inserted between adjacent spinous processes, and an insertion tool adapted to push the implant into position between the spinous processes.  
     
     
         14 . The implant of  claim 10  in combination with a kit that includes a cannula through which the implant can pass, said cannula adapted to be inserted between adjacent spinous processes, and an insertion tool adapted to push the implant into position between the spinous processes.  
     
     
         15 . The implant of  claim 13  wherein said kit includes a guide tool that can assist in the placement of the implant between the spinous processes.  
     
     
         16 . The implant of  claim 14  wherein said kit includes a guide tool that can assist in the placement of the implant between the spinous processes.  
     
     
         17 . The implant of  claim 1  in combination with a plurality of cannula, with each cannula being bigger than the one before, said plurality of cannula adapted to distract adjacent spinous processes as each of said bigger cannula are inserted.  
     
     
         18 . The implant of  claim 10  in combination with a plurality of cannula, with each cannula being bigger than the one before, said plurality of cannula adapted to distract adjacent spinous processes as each of said bigger cannula are inserted.  
     
     
         19 . A method for implanting an implant between adjacent spinous processes comprising the steps of: 
 laterally inserting a distraction device between adjacent spinous processes;    distracting the adjacent spinous processes with the distraction device;    inserting an implant between the adjacent spinous processes, wherein said implant includes:    a body that is adapted to fit between spinous processes;    said body including first and second ends and a middle section;    wherein at least one of said first and second ends has a diameter that is larger than the middle section; and    a plurality of ribs provided at least in said middle section; and    placing the middle section between the spinous processes with the first end on one side of the spinous processes and the second end on the other side of the spinous processes.    
     
     
         20 . A method for implanting an implant between adjacent spinous processes comprising the steps of: 
 laterally inserting a cannula between adjacent spinous processes;    distracting the adjacent spinous processes;    inserting an implant through the cannula and between the adjacent spinous processes, wherein said implant includes:    a body that is adapted to fit between spinous processes;    said body including first and second ends and a middle section;    wherein at least one of said first and second ends has a diameter that is larger than the middle section; and    a plurality of ribs provided at least in said middle section; and    placing the middle section between the spinous processes with the first end on one side of the spinous processes and the second end on the other side of the spinous processes.