Stand-alone spinal cage

Abstract

A spinal cage device for fusion of spinal vertebrae comprising a cage body having a cavity defined by upper, lower, and side walls; a piston selectively insertable into the cavity through a side wall, the piston having at least one angled surface; at least one channel extending through at least one of the upper wall and the lower wall; at least one fastening member moveable within the at least one channel between a first disengaged position and a second engaged position; and wherein in second engaged position the at least one fastening member is held substantially stationary relative to the cage body by contact with the piston. According to one aspect of the invention, the device includes a locking means for supplementing fixation of the piston to the cage body.

1 . A spinal cage device for fusion of spinal vertebrae comprising:
 a cage body having upper, lower, and side walls that a define a cavity, said upper and lower walls having bone growth openings therethrough, said side walls including a posterior side wall with a piston opening therethrough and an anterior side wall;   a piston having a piston body with anterior and posterior ends, said piston body being insertable along a longitudinal axis into said cavity through said piston opening, wherein said piston body comprise at least two angled surfaces adjacent to said anterior end;   at least two fastening member channels extending through said upper and lower walls;   at least two fastening members moveable within said at least two fastening member channels between a first disengaged position and a second engaged position;
 wherein in said second engaged position said at least two fastening members contact said piston body and are stationary relative to said cage body. 
   
     
     
         2 . The spinal cage device of  claim 1  wherein said fastening members comprises a generally cylindrical nail having a nail head with a proximal surface and a distal end, said nail head having an angled portion at least substantially corresponding to an angle of said at least two angled surfaces. 
     
     
         3 . The spinal cage device of  claim 1  further comprising:
 at least one screw mount positioned in the cavity; 
 a faceplate connected to the posterior end of the piston body, said faceplate being insertable into the piston opening; and 
 at least one screw insertable through said faceplate and matable with said at least one screw mount. 
 
     
     
         4 . The spinal cage device of  claim 1  wherein the at least two angled surfaces adjacent to said anterior end of said piston comprise upper and lower angled surfaces, wherein said fastening member comprises an angled engagement surface corresponding to the angle of at least one of said upper and lower surfaces, said fastening member tapering to a wedge at its distal end. 
     
     
         5 . The spinal cage device  claim 1  wherein each of said upper and lower angled surfaces is longitudinally alignable with at least one of said fastening member channels. 
     
     
         6 . The spinal cage device of  claim 1  further comprising:
 at least one lock opening proximal to said piston opening; and 
 a locking member rotatably-connected to said faceplate;
 wherein in said second engaged position said locking member is rotatable to a locked position in which a portion of said locking member extends into said at least one lock opening and a portion of said locking member is positioned adjacent said screw. 
 
 
     
     
         7 . The spinal cage device of  claim 1  wherein said at least one fastening member is porous to allow home growth therethrough.