Intervertebral Implant

Abstract

An intervertebral implant, specifically an artificial intervertebral disk, with a central axis, and an upper plate-shaped section, suitable for laying onto the base plate of a vertebral body lying on top, a lower plate-shaped section, suitable for laying onto the cover plate of a vertebral body lying below, wherein a central, plate-shaped section is arranged between the upper and the lower sections, a first circular-cylindrical rod with a longitudinal axle is arranged between the upper section and the central section, and a second circular-cylindrical rod with a longitudinal axle is arranged between the lower section and the central section.

1 . An intervertebral implant for insertion in-between adjacent upper and lower vertebrae, the implant comprising:
 an upper plate having a bone engaging surface for contacting at least a portion of the upper vertebrae and a bottom surface opposite the bone engaging surface;   a lower plate having a bone engaging surface for contacting at least a portion of the lower vertebrae and a top surface opposite the bone engaging surface; and   an intermediate plate having a first surface and a second surface;   wherein the bottom surface of the upper plate and the first surface of the intermediate plate define a first sliding surface and the top surface of the lower plate and the second surface of the intermediate plate define a second sliding surface, the first sliding surface being sized and configured to permit movement of the upper plate with respect to the intermediate plate in only one of the anterior-posterior direction or the medial-lateral direction, the second sliding surface being sized and configured to permit movement of the lower plate with respect to the intermediate plate in only the other of the anterior-posterior direction or the medial-lateral direction.   
     
     
         2 . The intervertebral implant of  claim 1 , further comprising a first cylindrical rod and a second cylindrical rod, the first cylindrical rod being disposed in-between the bottom surface of the upper plate and the first surface of the intermediate plate, the second cylindrical rod being disposed in-between the top surface of the lower plate and the second surface of the intermediate plate, the first cylindrical rod forming at least part of the first sliding surface and the second cylindrical rod forming at least part of the second sliding surface. 
     
     
         3 . The intervertebral implant of  claim 2 , further comprising at least one perimeter edge extending from one of the upper plate, intermediate plate and lower plate, the perimeter edge being sized and configured to prevent the first and second rod from escaping from the implant. 
     
     
         4 . The intervertebral implant of  claim 2 , wherein at least one of the upper plate, intermediate plate and lower plate includes one or more stops for limiting the amount of rotation of the first and second rods with respect to the intermediate plate. 
     
     
         5 . The intervertebral implant of  claim 2 , wherein the bottom surface of the upper plate and the first surface of the intermediate plate each include a groove formed therein for receiving the first cylindrical rod, the top surface of the lower plate and the second surface of the intermediate plate each including another groove formed therein for receiving the second cylindrical rod. 
     
     
         6 . The intervertebral implant of  claim 2 , wherein the first cylindrical rod is arranged in the anterior-posterior direction and the second cylindrical rod is arranged in the medial-lateral direction 
     
     
         7 . The intervertebral implant of  claim 6 , wherein the implant further comprises a central axis, the first cylindrical rod intersecting the central axis while the second cylindrical rod is separated from the central axis by a distance X. 
     
     
         8 . The intervertebral implant of  claim 2 , wherein at least one of the bottom surface of the upper plate or the first surface of the intermediate plate includes a stop to limit the movement of the first cylindrical rod and wherein at least one of the top surface of the lower plate or the second surface of the intermediate plate includes a stop to limit the movement of the second cylindrical rod. 
     
     
         9 . The intervertebral implant of  claim 1 , further comprising means for joining the upper and lower plates. 
     
     
         10 . The intervertebral implant of  claim 1 , further comprising means for temporary fixing the mobility of the upper and lower plates. 
     
     
         11 . The intervertebral implant of  claim 1 , wherein the upper and lower plates each include at least one hole sized and configured for receiving a bone screw for securing the implant to the adjacent vertebrae. 
     
     
         12 . The intervertebral implant of  claim 1 , further comprising means for limiting the movement of the upper and lower plates with respect to one another. 
     
     
         13 . The intervertebral implant of  claim 1 , further comprising at least one spring member, the at least one spring member being attached to the upper and lower plates. 
     
     
         14 . An intervertebral implant for insertion in-between adjacent upper and lower vertebrae, the implant comprising:
 an upper plate having a bone engaging surface for contacting at least a portion of the upper vertebrae and a bottom surface;   a lower plate having a bone engaging surface for contacting at least a portion of the lower vertebrae and a top surface; and   an intermediate plate having a first surface and a second surface;   wherein the bottom surface of the upper plate and the first surface of the intermediate plate define a first sliding surface and the top surface of the lower plate and the second surface of the intermediate plate define a second sliding surface;   wherein one of the first and second sliding surfaces permits movement in the anterior-posterior direction while the other of the first and second sliding surfaces permits movement in the medio-lateral direction.   
     
     
         15 . An intervertebral implant for insertion in-between adjacent upper and lower vertebrae, the implant comprising:
 an upper plate having a bone engaging surface for contacting at least a portion of the upper vertebrae and a bottom surface opposite the bone engaging surface;   a lower plate having a bone engaging surface for contacting at least a portion of the lower vertebrae and a top surface opposite the bone engaging surface; and   an intermediate plate having a first surface and a second surface;   wherein the bottom surface of the upper plate and the first surface of the intermediate plate define a first sliding surface and the top surface of the lower plate and the second surface of the intermediate plate define a second sliding surface, the first sliding surface being sized and configured to permit movement of the upper plate with respect to the intermediate plate in a first direction, the second sliding surface being sized and configured to permit movement of the lower plate with respect to the intermediate plate in a second direction, the second direction being substantially transverse to the first direction.