Intervertebral disc prosthesis
AssigneeSynthes USA, LLC
InventorsArmin Studer, Jason Trachsel, Martin Wymann
Life of this patent
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Abstract
Intervertebral disc prosthesis comprising an upper apposition plate appropriate to rest against the base plate of a vertebra, an apposition plate spaced apart from the apposition plate and suitable to rest against the upper plate of a vertebra, a plurality of elastic devices mounted between the two apposition plates and in their peripheral zones in a manner that the two apposition plates shall be displaceable in mutually resilient manner, and a central axis which runs essentially perpendicularly to the two apposition plates, the elastic devices being designed/configured in a manner that the intervertebral disc prosthesis as a whole exhibits asymmetrical stiffness.
Claims20
An intervertebral disc prosthesis comprising:
- a first plate configured to engage a first vertebrae;
- a second plate configured to engage a second vertebrae;
- and
- first and second elastic elements disposed at least partially between the first and second plates;
- wherein the first elastic element has a greater stiffness than the second elastic element, such that the prosthesis is more stiff in a first direction than in a second direction.
An intervertebral disc prosthesis comprising:
- a first plate configured to engage a first vertebrae;
- a second plate configured to engage a second vertebrae;
- an outer perimeter;
- a central axis substantially perpendicular to the first and second plates;
- and
- a first elastic element disposed at least partially between the first and second plates, and at least partially disposed proximate the outer perimeter;
- wherein the prosthesis is asymmetrically stiff with respect to the central axis.
An intervertebral disc prosthesis comprising:
- a first plate configured to engage a first vertebrae;
- a second plate configured to engage a second vertebrae;
- and
- a coiled elastic element disposed at least partially between the first and second plates;
- wherein the coiled elastic element has a first portion having a first stiffness, and a second portion having a second stiffness;
- and
- wherein the first stiffness is greater than the second stiffness, such that the prosthesis is more stiff in a first direction than in a second direction.
Dependencies are inferred from the claim text.