Filing Information

Inventor(s)	Greg Marik · Kevin Foley · Tom Francis · Randall Allard ·
Assignee(s)	Warsaw Orthopedic, Inc. ·  View assignee updates
Primary Examiner	Corrine McDermott ·
Assistant Examiner	Cheryl Miller ·
Application Number	US10806961
Filing date	03/23/2004
Issue date	12/29/2009
Prior Publication Data	US20050216086 - 09/29/2005
Predicted expiration date	06/13/2024
Patent term adjustment	82
U.S. Classifications	623/171.4  · 623/171.5  ·
International Classifications	A61F244  ·
Kind Code	B2

Patent Family

Abstract

An intervertebral implant comprises a first member for engaging a first vertebral body and a second member for engaging a second vertebral body. The first member has a first surface with a first curve, and the second member has a second surface with a second curve. The first member is translatable with respect to the second member and the second curve is positioned within the first curve to bias the first and second curved surfaces towards central alignment along a longitudinal axis passing through the first and second vertebral bodies.

Independent Claims | See all claims (17)

1. 1. An intervertebral implant comprising: a first member for engaging a first vertebra, the first member comprising a concave first surface, the concave first surface having a substantially constant first radius of curvature; a second member for engaging a second vertebra, the second member comprising a convex second surface and a tapered surface extending outwardly from the convex second surface, the convex second surface having a substantially constant second radius of curvature, the second radius of curvature being smaller than the first radius of curvature; and a center member positioned at least partially between the first member and the second member and in sliding articulating engagement with the first and second members, the center member comprising: a convex third surface for articulating with the concave first surface of the first member, the third surface having a substantially constant third radius of curvature substantially similar to the first radius of curvature, a concave fourth surface for articulating with the convex second surface of the second member, the concave fourth surface having a substantially constant fourth radius of curvature substantially similar to the second radius of curvature, a convex fifth surface extending substantially around the concave fourth surface, the convex fifth surface having a substantially constant fifth radius of curvature substantially equal to the first radius of curvature, the convex fifth surface configured for articulating with the tapered surface of the second member, the convex fifth surface being spaced from the tapered surface in a neutral position and in contact with the tapered surface in an articulation position, and a sidewall extending between the convex third surface and the convex fifth surface, the sidewall having a substantially circular outer profile; wherein the first member and the second member are formed of a relatively rigid biocompatible material and wherein the third and fourth surfaces of the center member are formed of an outer material that is harder than an inner material closer to a core of the center member.
2. 8. An intervertebral implant comprising: a first member for fixedly engaging a first vertebral body, the first member comprising a first surface with a first curve defining a concave recess with a substantially circular boundary, the first curve having a first radius of curvature; a second member for fixedly engaging a second vertebral body, the second member comprising a second surface with a second curve defining a convex projection with a substantially circular boundary, the second curve having a second radius of curvature smaller than the first radius of curvature; and a center member positioned between the first member and the second member, the center member in sliding articulating engagement with the first and second members and comprising: a convex third surface for movably mating with the concave recess defined by the first curve of the first surface, the third surface having a third radius of curvature substantially similar to the first radius of curvature, a fourth surface having a concave central portion and a convex outer portion extending substantially around the concave central portion, the concave central portion for movably mating with the convex projection defined by the second curve of the second surface, the concave central portion having a substantially circular boundary and a fourth radius of curvature substantially similar to the second radius of curvature, and the convex outer portion having a fifth radius of curvature substantially similar to the first radius of curvature; wherein the first and second members are translatable with respect to one another via the sliding articulating engagement with the center member and wherein the first and second members are biased towards a central alignment where the first and second members are substantially aligned with one another; wherein the center member articulates with respect to the first and second members such that the convex outer portion of the center member is spaced from the second member in the central alignment and is in contact with a surface of the second member surrounding the convex projection in at least some articulation positions; and wherein the first member and the second member are formed of a relatively rigid biocompatible material and wherein the third and fourth surfaces of the center member are formed of an outer material that is harder than an inner material closer to a core of the center member.