INTERVERTEBRAL DISC PROSTHESIS
An intervertebral disc prosthesis includes a base plate, a top plate, a central axis extending through the center of the base plate and the top plate, and at least two springs arranged between the base plate and the top plate. The springs each have a loop-shaped section and two free ends. One of the free ends of the springs is connected to the base plate and the other one of the free ends is connected to the top plate. The loop-shaped section is directed away from the central axis.
1 . An intervertebral disc prosthesis comprising:
a base plate;
a top plate, and a central axis extending through a center of the base plate and the top plate;
a plurality of springs circumferentially spaced apart and arranged about the central axis between the base plate and the top plate, each spring having a loop-shaped section and two free ends;
a fastening device to connect the base plate to the top plate;
wherein one of the free ends of each spring is connected to the base plate and the other one of the free ends is connected to the top plate; and
wherein the loop-shaped section of each spring is directed away from the central axis.
2 . An intervertebral disc prosthesis according to claim 1 , wherein each of the springs is a substantially flat strip.
3 . An intervertebral disc prosthesis according to claim 1 , comprising a clamping device to clamp the free ends of the springs to the base plate and the top plate.
4 . An intervertebral disc prosthesis according to claim 1 , wherein the base plate and the top plate each have a projection coaxial with the central axis, the projections facing each other.
5 . An intervertebral disc prosthesis according to claim 4 , wherein the ends of the springs are clamped to the projections.
6 . An intervertebral disc prosthesis according to claim 1 , further comprising a damping element arranged between the base plate and the top plate.
7 . An intervertebral disc prosthesis according to claim 1 , wherein the springs are made from a material exhibiting super-elasticity.
8 . An intervertebral disc prosthesis according to claim 1 , further comprising a flexible protection sleeve arranged between the base plate and the top plate.
9 . An intervertebral disc prosthesis according to claim 1 , wherein the sides of the base plate and the top plate which are opposite to the springs comprise an engagement structure for engagement with an adjacent end plate of a vertebra.
10 . An intervertebral disc prosthesis according to claim 1 , wherein the free ends are adjacent the loop-shaped section.
11 . An intervertebral disc prosthesis according to claim 7 , wherein the springs comprise a shape memory alloy.
12 . An intervertebral disc prosthesis according to claim 6 , wherein the damping element is an elastomer.
13 . An intervertebral disc prosthesis according to claim 1 , wherein the fastening device comprises a damping element, and wherein the base plate is coupled to the top plate with the damping element.
14 . An intervertebral disc prosthesis according to claim 1 , wherein the fastening device is coaxial with the central axis.
15 . An intervertebral disc prosthesis according to claim 1 , wherein the fastening device comprises a clamping device to clamp the free ends of the springs to the base plate and the top plate.
16 . A method of implanting an intervertebral prosthesis comprising a base plate, a top plate, and a central axis extending through a center of the base plate and the top plate, a plurality of springs circumferentially spaced apart and arranged about the central axis between the base plate and the top plate, each spring having a loop-shaped section and two free ends, and a fastening device to connect the base plate to the top plate, wherein one of the free ends of each spring is connected to the base plate and the other one of the free ends is connected to the top plate, wherein the loop-shaped section is directed away from the central axis, the method comprising:
compressing the prosthesis for insertion between two adjacent vertebrae;
inserting the prosthesis between the two adjacent vertebrae;
wherein the top plate and the base plate engage a corresponding vertebrae;
wherein each of the springs is configured to any one of compress and expand responsive to movement of the base plate relative to the top plate.
17 . The method of claim 16 , wherein the movement of the base plate relative to the top plate is damped with a damping element.
18 . The method of claim 16 , wherein the movement of the base plate relative to the top plate comprises rotation of the base plate relative to the top plate about the central axis.
19 . A method of assembling an intervertebral prosthesis comprising a base plate, a top plate, and a central axis extending through a center of the base plate and the top plate, a plurality of springs circumferentially spaced apart and arranged about the central axis between the base plate and the top plate, each spring having a loop-shaped section and two free ends, and a fastening device to connect the base plate to the top plate, wherein one of the free ends of each spring is connected to the base plate and the other one of the free ends is connected to the top plate, wherein the loop-shaped section is directed away from the central axis, the method comprising:
arranging the at least two springs between the base plate and the top plate, the loop-shaped section of each spring being directed away from the central axis; and
connecting the base plate to the top plate with the fastening device, the connecting of the base plate to the top plate connecting one of the free ends of each spring to the base plate and the other one of the free ends of each spring to the top plate.
20 . The method of claim 19 , further comprising placing a damping element between the base plate and the top plate.
21 . The method of claim 19 , wherein the connecting of the springs to the base plate and the top plate comprises clamping the free ends of the springs to the base plate and the top plate, respectively, with the fastening device.
22 . The method of claim 19 , further comprising placing a flexible protection sleeve between the base plate and the top plate.