Intervertebral spacer device having a wave washer force restoring element

• US 6,758,861 B2
• Filed: 10/16/2002
• Issued: 07/06/2004
• Est. Priority Date: 07/16/2001
• Status: Expired due to Fees

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Spinecore, Inc. (Stryker Corporation)
• Inventors: Ralph, James D., Errico, Joseph P., Tatar, Stephen
• Primary Examiner(s): Robert, Eduardo C.
• Application Number:
  US10/272,580
• Publication Number:
  US 20030040801A1
• Time in Patent Office: 629 Days
• Field of Search: 623/17.11, 623/17.13, 623/17.14, 623/17.15, 623/17.16, 606/61
• US Class Current: 623/17.13
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30171 rosette- or star-shaped
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30291 spirally-coiled, i.e. having a 2D spiral cross-section
• CPC Class Codes: A61F 2002/30326 differing in height or in length
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30518 with possibility of relative movement between the prosthetic parts
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30565 having spring elements
• CPC Class Codes: A61F 2002/30573 2-D spiral springs
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/005 : Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0037 : differing in height or in length
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00365 : Proteins; Polypeptides; Degradation products thereof

Abstract

An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one force restoring element. The preferred force restoring mechanism is a wave washer. In a first embodiment the wave washer is ring-shaped. In a second embodiment the wave washer is spiral-shaped.

Claims

1. An intervertebral spacer device, comprising:

first and second plates, the plates being disposed in a spaced apart relationship such that one plate surface of the first plate faces one plate surface of the second plate, the facing surfaces being inner surfaces, and alternative faces of each plate being outer surfaces; and

at toast one restoring force providing element disposed between the inner surfaces of the first and second plates, and disposed such that a compressive load applied to the outer surfaces of the plates is counteracted by the at least one restoring force providing element, the at least one restoring force providing element including at least one wave washer, the at least one wave washer having a longitudinally undulating circumferential extent.

2. The device as set forth in claim 1, wherein the at least one wave washer comprises a ring-shaped wave washer, the ring-shaped wave washer having a longitudinally undulating circumferential extent forming art uninterrupted circular hoop.

3. The device as set forth in claim 1, wherein the at least one wave washer comprises a ring-shaped wave washer, the ring-shaped wave washer having a longitudinally undulating circumferential extent forming a circular hoop interrupted by a radial slot.

4. The device as set forth in claim 1, wherein the at least one wave washer comprises a spiral-shaped wave washer, the spiral-shaped wave washer having a longitudinally undulating extent tat sweeps through an angle greater than 360 degrees, such that the extent spirals inwardly from relatively larger-diameter outer ring portions to increasingly relatively smaller-diameter inner ring portions, the outer and inner ring pardons undulating in the same laterally extending plane.

5. The device as set forth in claim 1, further comprising a flexible circumferential skirt disposed about and between lateral perimeters of the first and second plate members, therein defining an interior volume of the device in which the at least one wave washer is disposed.

6. The device as set forth in claim 5, wherein the flexible circumferential skirt comprises a resilient material.

7. The device as set forth in claim 5, wherein the flexible circumferential skirt is porous.

8. The device as set forth in claim 1, wherein the at least one wave washer comprises multiple wave washers.

9. The device as set forth in claim 8, wherein the multiple wave washers comprise a plurality of concentric wave washers.

10. The device as set forth in claim 1, wherein at least one of the first and second plates includes a wave washer securing mechanism mounted to the inner surface thereof.

11. An intervertebral spacer device comprising

first and second plates, the plates being disposed in a spaced apart relationship such that one plate surface of the first plate faces one plate surface of the second plate, the facing surfaces being inner surfaces, and alternative faces of each plate being outer surfaces;

and

at least one restoring force providing element disposed between the inner surfaces of the first and second plates, and disposed such that a compressive load applied to the outer surfaces of the plates is counteracted by at least one spiral-shaped wave washer, the the spiral-shaped wave washer having a longitudinally undulating extent that sweeps through an angle greater than 360 degrees, such that the extent spirals inwardly from relatively larger-diameter outer ring portions to increasingly relatively smaller-diameter inner ring portions, the outer and inner ring portions undulating in the same laterally extending plane.

12. The device as set forth in claim 11, further comprising a flexible circumferential skirt disposed about and between lateral perimeters of the first and second plates, therein defining an interior volume of the device in which the at least one spiral-shaped wave washer is disposed.

13. The device as set forth in claim 12, wherein the flexible circumferential skirt comprises a resilient material.

14. The device as set forth in claim 12, wherein the flexible circumferential skirt is porous.

15. The device as set forth in claim 11, wherein at least one of the first and second plates includes a wave washer securing mechanism mounted to the inner surface thereof.

16. An intervertebral spacer device comprising:

first and second plates, the plates being disposed in a spaced apart relationship such that one plate surface of the first plate faces one plate surface of the second plate, the facing surfaces being inner surfaces, and the alternative faces of each plate being outer surfaces; and

at least one ring-shaped wave washer disposed between the inner surfaces of the first and second plates, and disposed such that &

compressive load applied to the outer surfaces of the plates is counteracted by the ring-shaped wave washer, the ring-shaped wave washer having a longitudinally undulating circumferential extent forming an uninterrupted circular hoop.

17. The device as set forth in claim 16, wherein the ring-shaped wave washer further includes a radial slot.

18. The device as set forth in claim 16, further comprising a flexible circumferential skirt disposed about and between lateral perimeters of the first and second plates, therein defining an interior volume of the device in which the at least one ring-shaped wave washer is disposed.

19. The device as set forth in claim 18, wherein the flexible circumferential skirt comprises a resilient material.