Check reins for artificial disc replacements

Abstract

Check reins in the form of elongated members are used to limit the extreme range of motion which would otherwise be permitted by some ADR designs. The check reins serve two main purposes. First, they retain disc spacers, if present. Additionally, the wedge shape of ADRs and the removal of the Anterior Longitudinal Ligament (ALL) and a portion of the Annulus Fibrosus (AF) to insert the ADR from an anterior approach, favor anterior extrusion of disc spacers. In preferred embodiments the check reins are therefore limited to the anterior portion of the periphery of the ADR. Second, check reins serve to prevent excessive spinal motion. Again, although they may be helpful in other locations, anterior check reins help restore the motion limiting functions of the ALL and AF that were removed in anterior approaches to the spine.

1 . Apparatus for stabilizing an artificial disc replacement (ADR) of the type wherein a mobile member is disposed between opposing upper and lower vertebrae having endplates with anterior, lateral, and posterior peripheral regions, the apparatus comprising; 
 one or more elongated elements spanning one of the peripheral regions, each having two ends, one affixed to the upper end plate and/or vertebrae, and another affixed to the lower end plate and/or vertebrae.    
     
     
         2 . The apparatus of  claim 1 , wherein the elongated elements are limited to the anterior region.  
     
     
         3 . The apparatus of  claim 1 , wherein the elongated elements are at least partially elastic.  
     
     
         4 . The apparatus of  claim 1 , including at least two elongated elements that cross one another.  
     
     
         5 . The apparatus of  claim 1 , including at least one of the elongated elements is tightened in-situ.  
     
     
         6 . The apparatus of  claim 1 , including at least one of the elongated elements is braided.