Device for establishing an anatomical reference point of an intervertebral disc

Abstract

The disclosure relates to a device for establishing an anatomical reference point of an intervertebral disc for the attachment of at least one instrument intended for the implantation, through a posterior or posterolateral approach, of a disc prosthesis or osteosynthesis cage as a replacement for the intervertebral disc. The device includes at least two means for bone anchorage each intended to be attached to a vertebra adjacent to the disc, a coupling element for the instrument and elements for adjusting the position of the coupling element relative to the position of the disc.

1 . A device for establishing an anatomical reference point of an intervertebral disc for the attachment of at least one instrument intended for the implantation, through a posterior or posterolateral approach, of a disc prosthesis or osteosynthesis cage as a replacement for the intervertebral disc, the device comprising:
 first and second bone anchors each adapted to be attached to a vertebra;   a coupling element on which the instrument is intended to be attached, the coupling element being mounted between the first and the second bone anchors; and   elements operably adjusting a position of the coupling element relative to a position of the intervertebral disc.   
     
     
         2 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 1 , wherein the adjusting elements comprise a first and a second reference element of the intervertebral disc to be replaced, with the first element establishing a reference point relative to the spinous processes of the vertebra surrounding the intervertebral disc to be replaced, the second element establishing a reference point indicating the direction of the intervertebral disc intended to be replaced, and the second element being mounted to move on the first element. 
     
     
         3 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 1 , wherein the adjusting elements further comprise:
 a platform having a longitudinal axis provided with an element for viewing the intervertebral disc having a geometrical axis, the viewing element being mounted to move on the platform so as to orient the geometrical axis in the direction of the intervertebral disc; and   a connector operably connecting the platform to the first and second bone anchors, the connector being arranged to form a ball and socket link.   
     
     
         4 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the platform and the viewing element respectively compose the first and second reference point elements. 
     
     
         5 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the viewing element is arranged with the platform so as to have a degree of freedom in translation along the longitudinal axis. 
     
     
         6 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the viewing element is arranged with the platform so as to have a degree of freedom in rotation about an axis perpendicular to the longitudinal axis. 
     
     
         7 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the adjusting elements comprise means for adjusting the orientation of the viewing element arranged for enabling the pivoting of the viewing element about an axis perpendicular to the longitudinal axis. 
     
     
         8 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 7 , wherein the adjusting means comprise an intermediate part placed between the viewing element and the platform, the intermediate part having a convex face whereon the viewing element is mounted to move, with the intermediate part having a degree of freedom in translation along the longitudinal axis. 
     
     
         9 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the coupling element is mounted to slide along the viewing element. 
     
     
         10 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the coupling element comprises two coupling points for the respective attachment of an implantation instrument, with both attachment points being positioned on either side of the viewing element. 
     
     
         11 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the device comprises first and second means for respectively blocking the platform on the first and second bone anchors and the viewing element on the platform. 
     
     
         12 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 3 , wherein the platform further comprises additional coupling means enabling to attach the device on a holding equipment able to be attached on a support and provided with complementary coupling means. 
     
     
         13 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 1 , wherein the device comprises a linking bar able to link the first and second bone anchors together, the adjusting element being mounted on the linking bar. 
     
     
         14 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 13 , wherein the adjusting elements and the linking bar comprise a mutually associated ball and socket link. 
     
     
         15 . A device for establishing an anatomical reference point of an intervertebral disc according to  claim 14 , wherein the mutually associated link further comprises a spherical joint provided on one of the elements composed of the adjusting elements and of the linking bar, the spherical joint cooperating with a recess having a matching shape provided on the other element. 
     
     
         16 . A system enabling the implantation of a disc prosthesis or an osteosynthesis cage through a posterior or posterolateral approach with the system including a device for establishing an anatomical reference point of an intervertebral disc, the system comprising:
 first and second bone anchors each adapted to be attached to a vertebra;   a coupling element on which the instrument is intended to be attached, the coupling element being mounted between the first and the second bone anchors;   elements operably adjusting a position of the coupling element relative to a position of the intervertebral disc; and   
       at least one instrument for the implantation of the disc prosthesis or osteosynthesis cage fixed on the device. 
     
     
         17 . A system enabling the implantation of a disc prosthesis or an osteosynthesis cage according to  claim 16 , wherein the implantation instrument comprises a linking arm, one end of which is mounted to be hinged on the coupling element of the device, and the other end of the arm is provided with a tubular portion curved towards the intervertebral disc to be replaced. 
     
     
         18 . A system enabling the implantation of a disc prosthesis or an osteosynthesis cage according to  claim 16 , wherein the implantation instrument comprises a linking arm mounted to be fixed on the coupling element, with the linking arm including a receiver operably receiving a tubular portion having a curved or straight shape and configured for holding the tubular portion in a position oriented towards the intervertebral disc to be replaced.