Device for elastically stabilizing vertebral bodies
AssigneeSynthes USA, LLC
InventorsStephan Hartmann, Armin Studer
Life of this patent
Estimating the term…
Abstract
A device for elastically stabilizing vertebral bodies includes at least two bone anchoring means, each having a central axis and a head segment. The device also includes elastic means that can be joined to the head segments of two adjacent bone anchoring means in such a manner that the longitudinal axis of the elastic means extends transversely to the central axes of the bone anchoring means. Under compressive loads, the elastic means has a progressive spring characteristic. The elastic means is manufactured from a metallic material and has a plurality of spring coils, of which at least two spring coils have a geometric dimension which is different from the other spring coils.
Claims20
A device for dynamic stabilization of vertebral bodies, the device comprising:
- at least a first and second bone anchoring device each having a head segment;
- and an elastic means having a first end section, a second end section and a longitudinal axis, the first end section of the elastic means connectable to the head segments of the first bone anchoring device and the second end section of the elastic means connectable to the head segment of the second bone anchoring device such that the longitudinal axis extends between the first and second bone anchoring devices, wherein:
- the elastic means is made of a metallic material and comprises a plurality of helical spring coils having a pitch δ, at least two of the spring coils have at least one geometric dimension which is different than the other of the spring coils, and the pitch of the spring coils varies continuously along the longitudinal axis, and under a compressive load, the elastic means has a progressive spring characteristic, wherein the pitch of the helical spring coils increases from center towards the ends of the plurality of helical spring coils.
A device for the elastic stabilization of bodies of the vertebra, the device comprising:
- at least a first and second bone anchoring device each having a head segment;
- and
- an elastic means having a first end section, a second end section, a longitudinal axis and a center located between the first end section and the second end section, the first end section of the elastic device connectable to the head segments of the first bone anchoring device, the second end section of the elastic device connectable to the head segment of the second bone anchoring device such that the longitudinal axis extends transversely between the first and second bone anchoring devices, wherein:
- the elastic means is made of a metallic material, and comprises a plurality of spring coils having a pitch δ that continuously increases along the longitudinal axis from the center towards the ends of the plurality of spring coils, of which at least two of the spring coils have at least one geometric dimension which is different than the other of the spring coils, and under a compressive load, the elastic means has a progressive spring characteristic.
A device for the elastic stabilization of bodies of the vertebra, the device comprising:
- at least a first and second bone anchoring device each having a head segment;
- and
- an elastic means having a first end section, a second end section, a longitudinal axis and a center located between the first end section and the second end section, the first end section of the elastic device connectable to the head segments of the first bone anchoring device, the second end section of the elastic device connectable to the head segment of the second bone anchoring device such that the longitudinal axis extends transversely between the first and second bone anchoring devices, wherein the elastic means is made of a metallic material, and comprises a plurality of spring coils having a pitch δ, a cross sectional area perpendicular to the longitudinal axis and a slot width x between adjacent spring coils,
- wherein the pitch δ continuously increases along the longitudinal axis from the center towards the ends of the plurality of spring coils, the cross sectional area of the spring coils have a height h measured parallel to the longitudinal axis that increases from the center towards the ends of the plurality of the helical spring coils, and the slot width x remains constant along the entire plurality of helical spring coils, and under a compressive load, the elastic means has a progressive spring characteristic.
Dependencies are inferred from the claim text.