Dynamized Interspinal Implant

Abstract

An interspinous process implant for insertion between adjacent spinous processes, the implant having a flexible body having i) an upper posterior portion having an upper surface adapted to bear upon an upper spinous process, ii) a lower posterior portion having a lower surface adapted to bear upon a lower spinous process, and iii) an arcuate, flexible anterior wall connecting the upper and lower portions, wherein the anterior wall has a narrowed portion.

We claim: 
     
         1 . An interspinous implant for insertion between adjacent spinous processes, the implant comprising:
 a) a flexible body comprising:
 i) an upper posterior portion having an upper surface adapted to bear upon an upper spinous process, 
 ii) a lower posterior portion having a lower surface adapted to bear upon a lower spinous process, and 
 iii) an arcuate, flexible anterior wall connecting the upper and lower portions, 
   
       wherein the anterior wall has a narrowed portion. 
     
     
         2 . The implant of  claim 1  wherein the flexible body is substantially U-shaped. 
     
     
         3 . The implant of  claim 1  wherein the flexible body further comprises:
 iv) an arcuate, flexible posterior wall connecting the upper and lower portions. 
 
     
     
         4 . The implant of  claim 1  further comprising:
 b) a lower pair of extensions extending downward from the lower surface of the lower portion of the flexible body and collectively defining a lower bracket. 
 
     
     
         5 . The implant of  claim 4  wherein each extension comprises a transverse throughhole adapted for fixing the implant to the adjacent spinous processes. 
     
     
         6 . The implant of  claim 5  further comprising:
 c) a fastening element having a first end extending through the first transverse throughole and a second end extending through the second transverse through hole. 
 
     
     
         7 . The implant of  claim 4  each extension comprises an inner wall and a fixation element extending inwardly from the inner wall, the fixation element adapted for fixing the implant to the adjacent spinous processes. 
     
     
         8 . The implant of  claim 1  wherein the upper and lower posterior portions are substantially non-parallel. 
     
     
         9 . The implant of  claim 1  wherein the flexible body is adapted to provide a stiffness of between 50 N/mm and 1000 N/mm. 
     
     
         10 . The implant of  claim 1  wherein the flexible body is adapted to provide a stiffness of between 100 N/mm and 500 N/mm.