Intervertebral prosthesis with a limit stop plate

• US 8,062,370 B2
• Filed: 07/25/2005
• Issued: 11/22/2011
• Est. Priority Date: 03/12/2002
• Status: Expired due to Fees

• Current Assignee: Cervitech, Inc. (Nuvasive Incorporated)
• Original Assignee: Cervitech, Inc. (Nuvasive Incorporated)
• Inventors: McAfee, Paul C., Keller, Arnold
• Primary Examiner(s): Pellegrino; Brian E.
• Application Number:
  US11/188,003
• Publication Number:
  US 20050256579A1
• Time in Patent Office: 2,311 Days
• Field of Search: 623 1711- 1716, 623/20.22, 623/20.23, 623 2026- 2028, 606/280, 606/287
• US Class Current: 623/17.14
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30392 Rotation
• CPC Class Codes: A61F 2002/30397 Limited lateral translation of the rib within a larger groove
• CPC Class Codes: A61F 2002/304 with additional means for limiting said sliding
• CPC Class Codes: A61F 2002/30517 using a locking plate
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30649 Ball-and-socket joints
• CPC Class Codes: A61F 2002/3065 Details of the ball-shaped head
• 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 2310/00011 Metals or alloys

Abstract

An intervertebral prosthesis, in particular for the cervical spine, includes a first cover plate to be connected to a first vertebral body, second cover plate to be connected to the second vertebral body, and a prosthesis core which forms an articulation with the second cover plate. The prosthesis core is held by seat of the first cover plate which is designed as a guide device. The core can be pushed into the guide device from the ventral side in the anterior-posterior (AP) direction relative to the first cover plate. A limit-stop plate is provided on the ventral edge of the first cover plate. This limit-stop plate is displaceable in a slide guide between a locking position and a nonlocking position.

Claims

1. An intervertebral prosthesis, comprising a first cover plate configured to be connected to a first vertebral body, a second cover plate configured to be connected to a second vertebral body, a prosthesis core which forms an articulation with the second cover plate and is held by a seat of the first cover plate, which seat is designed as a guide device into which the core can be moved from a ventral side relative to the first cover plate, and a limit-stop plate having a tongue portion extending perpendicularly from a wing portion, the limit-stop plate having a height such that the limit-stop plate does not interfere with relative motion between the prosthesis core and the second cover plate, and

wherein the first cover plate has, on a ventral edge, a slide guide with respect to which the limit-stop plate is displaceable between a locking position and a nonlocking position, and

wherein the slide guide for the limit-stop plate is formed by a slide-guide surface extending transverse to an anterior-posterior direction on the ventral edge of the first cover plate and by a pivot pin projecting from the slide-guide surface and on which the limit-stop plate is pivotably mounted, and

wherein, in the locking position, the limit-stop plate is positioned such that the tongue portion protrudes above a bottom surface of the first cover plate and the wing portion engages with a screw head located in a screw hole provided on the first cover plate, and in the nonlocking position, the limit-stop plate is positioned such that both the tongue portion and the wing portion are lowered below the bottom surface of the first cover plate and the wing portion does not interfere with placement of a screw in the screw hole provided on the first cover plate.

2. The prosthesis as claimed in claim 1, wherein the prosthesis core has an articulation surface that covers substantially the entire first cover plate.

3. The prosthesis as claimed in claim 2, wherein the prosthesis core is also movable relative to the first cover plate in the anterior-posterior direction when the limit-stop plate is positioned in the locking position.

4. The prosthesis as claimed in claim 1, wherein the limit-stop plate is made of resilient metal.

5. The prosthesis as claimed in claim 4, wherein the resilient material is pre-stressed such that the wing portion of the limit-stop plate presses against the slide guide surface.

6. The prosthesis as claimed in claim 1, further comprising an opening or depression in the limit-stop plate for engagement of a turning tool.

7. The prosthesis as claimed in claim 1, wherein when the limit-stop plate is positioned in the nonlocking position, both the tongue portion and the wing portion do not interfere with insertion of the prosthesis core.

8. The prosthesis as claimed in claim 1, wherein the limit-stop plate is T-shaped.

9. The prosthesis as claimed in claim 8, wherein the wing portion comprises a pair of extensions extending laterally from the tongue portion.

10. The prosthesis as claimed in claim 9, wherein the wing portions engage over more than one screw head located in more than one screw holes provided on the first cover plate.