Orthopedic device assembly with elements coupled by a retaining structure

1. An intervertebral prosthesis comprising:

a core element;

a pair of endplates at opposite ends of the core element for attaching the opposite ends of the core element to respective vertebrae,

wherein at least one of the endplates has a recess that receives one of the ends of the core element; and

a retaining mechanism that holds said one end of the core element in the recess,

wherein said retaining mechanism includes a retainer with an angular cross-section defined by a base portion and a flange portion projecting from the base portion,

wherein the base portion is received in a groove in a wall of the recess and the flange portion projects outwardly of the groove and overhangs a shoulder on the core element,

wherein the retainer has a series of flanges projecting from the base, the flanges being separated from each other by notches,

wherein the retainer is a flexible wire and the notches facilitate bending of the wire, and

wherein the groove extends peripherally in the wall of the recess and has an entrance externally of the wall for receiving the wire.

2. A prosthesis according to claim 1 , wherein the shoulder is part of a coupling member on the core element.

3. A prosthesis according to claim 2 , wherein the coupling member is a coupling plate at an end of the core element.

4. A prosthesis according to claim 1 , wherein the shoulder is part of a member that fits within an interior angle of the retainer and is embraced between a surface of the flange portion and an opposed surface of the groove.

5. A prosthesis according to claim 1 , wherein the construction of the prosthesis is replicated at opposite ends thereof.

6. A prosthesis according to claim 1 , wherein the core element includes elastomer.

7. A method of making an intervertebral prosthesis that includes the steps of:

providing a core element;

providing a pair of endplates at opposite ends of the core element for attaching the opposite ends of the core element to respective vertebrae,

wherein at least one of the endplates has a recess adapted to receive one of the ends of the core element; and

providing a retaining mechanism adapted to hold said one end of the core element in the recess,

wherein said retaining mechanism includes a retainer with an angular cross-section defined by a base portion and a flange portion projecting from the base portion;

inserting said one of the ends of the core element into said recess; and

employing said retaining mechanism to hold said one end of the core element in the recess by inserting the base portion of the retainer in the groove and positioning the flange portion of the retainer so as to project outwardly of the groove to overhang a shoulder, the groove being disposed in one of a wall of the recess and the core element, and the shoulder being disposed on the other of the core element and the wall of the recess,

wherein the retainer is provided with a series of flanges projecting from the base, with the flanges being separated from each other by notches,

wherein the retainer is provided as a flexible wire and the notches facilitate bending of the wire, and

wherein the groove is provided so that it extends peripherally in a wall of the recess and has an entrance externally of the wall for receiving the wire.

8. A method according to claim 7 , wherein the shoulder is provided as part of a coupling member on the core element.

9. A method according to claim 7 , wherein the coupling member is provided as a coupling plate at an end of the core element.

10. A method according to claim 7 , wherein the construction of the prosthesis is replicated at opposite ends thereof.

11. A method according to claim 7 , wherein the core element includes elastomer.