Intervertebral implant with fixation geometry

Abstract

An intervertebral spacer implant ( 80 ) is provided with a retention mechanism ( 86 ) to help alleviate expulsion and movement of the implant when placed in the spine while providing an implant that is easier to insert in the spine. In one embodiment the retention mechanism comprises a keel on at least one of the inferior or superior faces of the spacer implant preferably extending in an anterior-posterior direction. In another embodiment the implant comprises a spacer ( 84 ) and a plate ( 82 ), the plate comprising a supplemental or alternative retention mechanism. In one embodiment the retention mechanism comprises one or more holes ( 88 ) in the anterior end of the plate. In yet another embodiment, the retention mechanism comprises one or more blades that are in a first position when inserted and are preferably rotated to a second position that engages the superior and inferior vertebrae.

What is claimed is: 
     
         1 . An intervertebral implant comprising:
 a spacer having a first insertion end portion, a second end portion, an upper surface, and a lower surface, the spacer configured and dimensioned for insertion between adjacent vertebrae;   a plate secured to the second end portion of the spacer, the plate including at least one blade configured and dimensioned to penetrate the adjacent vertebrae; and   an actuator for causing the at least one blade to move and penetrate the adjacent vertebrae.   
     
     
         2 . The implant according to  claim 1 , wherein the at least one blade is configured to rotate from a first position wherein the blade is adjacent to the plate to a second position wherein the blade is not adjacent the plate. 
     
     
         3 . The implant according to  claim 2 , wherein the at least one blade is configured to provide compression when rotated into the second position. 
     
     
         4 . The implant according to  claim 2  further comprising a locking mechanism to prevent the at least one blade from rotating back to the first position. 
     
     
         5 . The implant according to  claim 1 , wherein the at least one blade comprises two blades. 
     
     
         6 . The implant according to  claim 5 , wherein the two blades include a first blade and a second blade, the first blade configured for extending beyond the upper surface of the spacer into a superior vertebrae and the second blade configured extending beyond the lower surface of the spacer into an inferior vertebrae. 
     
     
         7 . The implant according to  claim 1 , wherein the at least one blade is pointed and wedge-shaped to facilitate penetrating and cutting through the adjacent vertebrae. 
     
     
         8 . The implant according to  claim 1 , wherein the plate, the spacer, and the at least one blade are secured with a retention mechanism configured to be torsionally driven. 
     
     
         9 . The implant according to  claim 8 , wherein the retention mechanism has a recess configured to receive a tool to rotate the retention mechanism and the at least one blade relative to the plate and the spacer. 
     
     
         10 . The implant according to  claim 9 , wherein the recess is star-shaped. 
     
     
         11 . The implant according to  claim 8 , wherein the retention mechanism is rotated clockwise to secure the at least one blade substantially perpendicularly to the adjacent vertebrae. 
     
     
         12 . The implant according to  claim 8 , wherein the retention mechanism is rotated approximately 90° to insert the at least one blade into the adjacent vertebrae.