Intervertebral disk prosthesis
An intervertebral disk prosthesis is disclosed. The intervertebral disk prosthesis has a base plate, a top plate opposite the base plate, and an intervening core located between the top plate and base plate. One of the plates has a first concave contact face facing the core, which has an adjacent first convex contact face. A groove is provided around one of the contact faces in which an elastic ring is placed. When placed in the groove, the elastic ring is also in contact with the opposite contact face.
1. An intervertebral disk prosthesis for use in a vertebral column, comprising:
a base plate;
a top plate;
a core between the base plate and the top plate and having a longitudinal axis extending from the base plate to the top plate, a first curved surface on a side facing the top plate, and a second curved surface on a side facing the base plate, wherein at least the first curved surface is located on a first body of the core; and
an annular elastic member contacting an outer surface of the first body and spaced apart from the top plate, the elastic member being more elastically compressible than the first body,
wherein the top plate has a curved section intersecting said longitudinal axis and in sliding engagement with the first curved surface of the core, and
wherein the sliding engagement provides for rotational movement of the top plate substantially about said longitudinal axis, and for sliding movement to increase or decrease an angle formed between an axis of rotation of the top plate and said longitudinal axis.
2. The intervertebral disk prosthesis of claim 1 , wherein a first groove encircles one of the first curved surface of the core or the curved section of the top plate, and wherein a second elastic member is embedded in the first groove and contacts the other one of the first curved surface of the core or the curved section of the top plate.
3. The intervertebral disk prosthesis of claim 2 , wherein the other one of the curved surface of the first body or the curved section of the top plate is encircled by a second groove for engaging the second elastic member.
4. The intervertebral disk prosthesis of claim 2 , wherein the second curved surface is located on the first body of the core, and the base plate has a curved section on a side facing the core and in sliding engagement with the second curved surface, wherein a second groove encircles one of the second curved surface of the core or the curved section of the base plate, and wherein the annular elastic member is embedded in the second groove and contacts the other one of the second curved surface of the core or the curved section of the base plate.
5. The intervertebral disk prosthesis of claim 4 , wherein the other one of the second curved surface of the core or the curved section of the base plate is encircled by a third groove for engaging the annular elastic member.
6. The intervertebral disk prosthesis of claim 4 , wherein at least one of the curved sections of the top plate or the base plate is concave, and the corresponding curved surface of the core is convex.
7. The intervertebral disk prosthesis of claim 1 , wherein the base plate and the top plate each has an outer edge, and at least one of the base plate or the top plate has teeth on its outer edge extending vertically outwards away from the core to engage an adjacent wall of a vertebral body.
8. The intervertebral disk prosthesis of claim 1 , wherein the base plate and the top plate comprise steel or titanium, and the core comprises a body-compatible high molecular polyethylene synthetic material.
9. The intervertebral disk prosthesis of claim 1 , wherein the base plate comprises a cylindrical portion to accommodate a cylindrical casing configured to be placed on the cylindrical portion of the base plate.
10. The intervertebral disk prosthesis of claim 1 , wherein the elastic member is formed as part of the core and the core further comprises a second body on which the second curved surface is located, wherein the elastic member is between and separates the first and second bodies of the core, and wherein the base plate has a curved section on a side facing the core and in sliding engagement with the second curved surface.
11. The intervertebral disk prosthesis of claim 10 , wherein the elastic member is configured to extend primarily in a plane generally perpendicular to the vertebral column.
12. The intervertebral disk prosthesis of claim 10 , wherein the elastic member comprises an elastic ring.
13. The intervertebral disk prosthesis of claim 10 , wherein along the longitudinal axis a mandrel is provided to limit the relative movement between the base plate and the top plate about the longitudinal axis.
14. The intervertebral disk prosthesis of claim 10 , wherein the core has a bore extending from the base plate to the top plate and wherein a connecting sleeve is provided within the bore to engage the base plate and the top plate.
15. The intervertebral disk prosthesis of claim 14 , wherein at least one screw is screwed into the connecting sleeve to connect the base plate, the top plate, and the core with one another.
16. The intervertebral disk prosthesis of claim 10 , wherein at least one of the curved sections of the top plate or the base plate is concave, and the corresponding curved surface of the core is convex.
17. The intervertebral disk prosthesis of claim 10 , wherein the elastic member has a bore extending therethrough in a direction from the first body to the second body, and wherein the first body and the second body are located outside the bore.
18. The intervertebral disk prosthesis of claim 10 , wherein the elastic member completely separates the first body of the core from the second body of the core.
19. The intervertebral disk prosthesis of claim 1 , wherein the first curved surface of the core is convex and the curved section of the top plate is concave.
20. The intervertebral disk prosthesis of claim 1 , wherein the first curved surface of the core is concave and the curved section of the top plate is convex.
21. A method of treating a patient with a damaged intervertebral disk in a spinal column comprising the steps of:
a. removing a damaged vertebral disk; and
b. inserting an intervertebral disk prosthesis comprising a base plate, a top plate, a core between the base plate and the top plate and having a longitudinal axis extending from the base plate to the top plate, a first curved surface on a side facing the top plate, and a second curved surface on a side facing the base plate, wherein at least the first curved surface is located on a first body of the core, and an annular elastic member contacting an outer surface of the first body and spaced apart from the top plate, the elastic member being more elastically compressible than the first body, wherein the top plate has a curved section intersecting said longitudinal axis and in sliding engagement with the first curved surface of the core, and wherein the sliding engagement provides for rotational movement of the top plate substantially about said longitudinal axis, and for sliding movement to increase or decrease an angle formed between an axis of rotation of the top plate and said longitudinal axis, whereby said prosthesis cushions and dampens a load on the spinal column.
22. An intervertebral disk prosthesis for use in a vertebral column, comprising:
a base plate;
a top plate;
a core between the base plate and the top plate and having a longitudinal axis extending from the base plate to the top plate, the core comprising a first body having a first curved surface on a side facing the top plate; and
an annular elastic member contacting an outer surface of the first body and spaced apart from the top plate, the elastic member being more elastically compressible than the first body,
wherein the top plate has a curved section intersecting said longitudinal axis and in sliding engagement with the first curved surface of the core,
wherein the sliding engagement provides for rotational movement of the top plate substantially about said longitudinal axis, and for sliding movement to increase or decrease an angle formed between an axis of rotation of the top plate and said longitudinal axis, and
wherein a first groove encircles one of the first curved surface of the core or the curved section of the top plate, and wherein a second elastic member is embedded in the first groove and contacts the other one of the first curved surface of the core or the curved section of the top plate.
23. The intervertebral disk prosthesis of claim 22 , wherein the other one of the curved surface of the first body or the curved section of the top plate is encircled by a second groove for engaging the second elastic member.
24. The intervertebral disk prosthesis of claim 22 , wherein the core has a second curved surface on a side facing the base plate, and the base plate has a curved section on a side facing the core and in sliding engagement with the second curved surface, wherein a second groove encircles one of the second curved surface of the core or the curved section of the base plate, and wherein the annular elastic member is embedded in the second groove and contacts the other one of the second curved surface of the core or the curved section of the base plate.
25. The intervertebral disk prosthesis of claim 24 , wherein the other one of the second curved surface of the core or the curved section of the base plate is encircled by a third groove for engaging the annular elastic member.
26. The intervertebral disk prosthesis of claim 24 , wherein at least one of the curved sections of the top plate or the base plate is concave, and the corresponding curved surface of the core is convex.
27. An intervertebral disk prosthesis for use in a vertebral column, comprising:
a base plate;
a top plate;
a core between the base plate and the top plate and having a longitudinal axis extending from the base plate to the top plate, the core comprising a first body having a first curved surface on a side facing the top plate; and
an annular elastic member contacting an outer surface of the first body and spaced apart from the top plate, the elastic member being more elastically compressible than the first body,
wherein the top plate has a curved section intersecting said longitudinal axis and in sliding engagement with the first curved surface of the core,
wherein the sliding engagement provides for rotational movement of the top plate substantially about said longitudinal axis, and for sliding movement to increase or decrease an angle formed between an axis of rotation of the top plate and said longitudinal axis, and
wherein the base plate comprises a cylindrical portion to accommodate a cylindrical casing configured to be placed on the cylindrical portion of the base plate.
28. The intervertebral disk prosthesis of claim 27 , further comprising the cylindrical casing, wherein the cylindrical casing has two opposite ends and teeth located on one of its ends to engage an adjacent wall of a vertebral body.