Cage-type intervertebral implant

Claim 2

A cage for a cage-like intervetebral implant, comprising a member divided into cavities, wherein the cage comprises a dished inner side wall, a cambered outer side wall, a front part, and a rear part, a first, inner readius of curvature being allocated to the dished inner wall, and a second, outer radius of curvature being allocated to the cambered outer side wall; the side walls are connected to the front part and the rear part; the side walls are connected to at least one intermediate wall substantially perpendicular to the side walls, whereby the cage has at least two cavities; and the side walls, the front part, the rear part, and at least one intermediate wall form an upper and a lower cage surface, a first lordosis angle being formed between said upper and lower cage surfaces in a front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said front part—rear part direction, and second lordosis angle being formed between said upper and lower cage surfaces in an outer side wall—inner side wall direction perpendicular to said front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said outer side wall—inner side wall direction.

Claim 3

A cage according to claim 1 , wherein the inner side wall has a smaller height than the outer side wall, or the outer sidewall has a smaller height than the inner sidewall.

Claim 4

A cage according to claim 1 , wherein the front part and the rear part have a substantially equal second lordosis angle.

Claim 5

A cage according to one of claims 1 , wherein the first lordosis angle is 2° and 8°.

Claim 6

A cage according to claim 4 , wherein the first lordosis angle is 3°.

Claim 7

A cage according to claim 4 , wherein the first lordosis angle is 5°.

Claim 8

A cage according to one of claims 4 , wherein first lordosis angle is 7°.

Claim 9

A cage according to claims 1 , wherein the second lordosis angle is between 0.1° and 4°.

Claim 10

A cage according to claims 1 , wherein the first, inner radius of curvature and the second, outer radius of curvature have centers arranged offset to one another.

Claim 11

A cage according to claim 1 , wherein the inner radius of curvature is between 15 and 23 mm and the outer radius of curvature is between 18 mm and 26 mm.

Claim 12

A cage according to claim 1 , wherein the inner side wall has a least one opening.

Claim 13

A cage according to claim 1 , wherein the outer side wall has a least one opening.

Claim 14

A cage according to claim 1 , wherein the front part is rounded and has a least one beveled surface.

Claim 15

A cage according to claim 1 , wherein holes are provided in the front part and in the rear part for markers of a metal of high density, said markers comprising at least one of balls and pins.

Claim 16

A cage according to claim 14 , wherein tantalum is provided as the metals for the markers.

Claim 17

A cage according to claim 14 , wherein the markers are arranged as pins that are one of approximately perpendicular or parallel to a threaded hole.

Claim 18

A cage according to claim 14 , wherein said markers are pins and the pins are parallel to a threaded hole.

Claim 19

A cage according to claim 1 , wherein the cage surfaces have tabular raised portions which run substantially parallel to the cage surfaces.

Claim 20

A cage according to claim 1 , wherein the cage has a moment of tilt (M) directed in the direction of the center of the inner radius of curvature that is at least 1.30 times greater than the moment of tilt of a cuboidal cage of the same cross section, same length and comparable cage structure.

Claim 21

A cage according to claim 1 , wherein the cage comprises carbon fiber reinforced composites of CFK/PEEK and CFK/PEKEKK.

Claim 22

A cage according to claim 1 , wherein the cage comprises a Ti alloy.

Claim 23

A cage according to claim 21 , wherein said cage has one of a hydroxyapatite ceramic (HAK) coating or a tricalcium phosphate (TCP) coating.

Claim 24

A cage according to claim 1 , wherein said cage has a Cage Mass Index (CMI) according to Equation CMI=Volume of cage material/Volume of cage  (1) which for CFK/PEEK, CFK/PEKEKK, and CFK/PS is less that 0.25 and for Ti alloys, is less thatn 0.20.

Claim 25

A cage according to claim 23 , wherein a CMI for CFK reinforced PEEK, a CMI for CFK reinforced PEKEKK and a CMI for CFK reinforced PS is equal 0.22.

Claim 26

A cage according to claim 23 , wherein a CMI for titanium alloy is equal 0.17.

Claim 27

A cage for a cage-like intervertebral implant, comprising a member divided into cavities, wherein the cage comprises a dished inner side wall, a cambered outer side wall, a front part, and a rear part, a first, inner radius of curvature being allocated to the dished inner side wall, and a second, outer radius of curvature being allocated to the cambered outer side wall; the side walls are connected to the front part and the rear part; the side walls are connected to at least one intermediate wall substantially perpendicular to the side walls, whereby the cage has at least two cavities; and the side walls, the front part, the rear part, and the at least one intermediate wall form an upper and a lower cage surface, a first lordosis angle being formed between said upper and lower cage surfaces in a front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said front part—rear part direction, and a second lordosis angle being formed between said upper and lower cage surfaces in an outer side wall—inner wall direction perpendicular to said front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said outer side wall—inner side wall direction, wherein the rear part has in its middle a hole with an internal thread, which is surrounded by two guide elements which run substantially parallel or in a V-shape.

Claim 28

A cage for a cage-like intervertebral implant, comprising a member divided into cavities, wherein the cage comprises a dished inner side wall, a cambered outer side wall, a front part, and a rear part, a first, inner radius of curvature being allocated to the dished inner side wall, and a second, outer radius of curvature being allocated to the cambered outer side wall; the side walls are connected to the front part and the rear part; the side walls are connected to at least one intermediate wall substantially perpendicular to the side walls, whereby the cage has at least two cavities; and the side walls, the front part, the rear part, and the at least one intermediate wall form an upper and a lower cage surface, a first lordosis angle being formed between said upper and lower cage surfaces in a front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said front part—rear part direction, and a second lordosis angle being formed between said upper and lower cage surfaces in an outer side wall—inner wall direction perpendicular to said front part—rear part direction such that said upper and lower cage surfaces are not parallel to each other in said outer side wall—inner side wall direction, wherein the rear part has in its middle a hole with an internal thread, which is surrounded by two guide elements which run substantially parallel or in a V-shape.

Claim 29

A cage according to claim 26 , wherein the guide elements are arranged at one of approximately perpendicular, or about parallel, or at an angle of 0° to 90° to the cage surfaces around the threaded hole.

Claim 30

A cage according to claim 26 , wherein the internal thread is surrounded by recesses which run substantially parallel or in a V-shape.

Claim 31

A cage according to claim 26 , wherein the two guide elements are in a V-shape.

Claim 32

A cage according to claim 26 , wherein the guide elements are arranged approximately parallel to the cage surfaces around the hole.

Claim 33

A cage according to claim 26 , wherein the guide elements are arranged approximately at an angle between 0° and 90° to the cage surfaces around the hole.

Claim 34

A cage according to claim 26 , wherein the guide elements are arranged approximately at a 45° angle to the cage surfaces around the hole.

Claim 35

A cage for a cage-like intervertebral implant, the cage comprising: a member divided into cavities; a concave-curved inner sidewall having a first inner radius of curvature; a convex-curved outer sidewall having a second outer radius of curvature; a front portion; a rear portion where both the concave-curved sidewall and the convex-curved sidewall are connected to the front portion and the rear portion, the concave-curved sidewall and the convex-curved sidewall being connected to a least one partition substantially perpendicular to both the concave-curved sidewall and the convex-curved sidewall to form a cage with at least two cavities wherein the concave-curved sidewall, the convex-curved sidewall, the front portion, the rear portion and the at least one partition forms an upper cage surface and a lower cage surface where the upper cage surface and the lower cage surface form a first lordosis angle in a front portion—rear portion direction such that the upper cage surface and a lower cage surface are not parallel to each other in the front portion—rear portion direction and the upper cage surface and the lower cage surface form a second lordosis angle in a concave-curved sidewall—convex-curved sidewall direction such that the upper cage surface and the lower cage surface are not parallel to each other in the concave-curved sidewall—convex-curved sidewall direction.

Claim 36

A cage for a cage-like intervertebral implant, the cage comprising: a member divided into cavities; a concave-curved inner sidewall having a first inner radius of curvature; a convex-curved outer sidewall having a second outer radius of curvature; a front portion; a rear portion where both the concave-curved sidewall and the convex-curved sidewall are connected to the front portion and the rear portion, the concave-curved sidewall and the convex-curved sidewall being connected to a least one partition substantially perpendicular to both the concave-curved sidewall and the convex-curved sidewall to form a cage with at least two cavities wherein the concave-curved sidewall, the convex-curved sidewall, the front portion, the rear portion and the at least one partition forms an upper cage surface and a lower cage surface where the upper cage surface and the lower cage surface form a first lordosis angle in a front portion—rear portion direction such that the upper cage surface and a lower cage surface are not parallel to each other in the front portion—rear portion direction and the upper cage surface and the lower cage surface form a second lordosis angle in a concave-curved sidewall—convex-curved sidewall direction such that the upper cage surface and the lower cage surface are not parallel to each other in the concave-curved sidewall—convex-curved sidewall direction.

Claim 37

A cage according to claim 33 , wherein the outer sidewall has a smaller height that the inner sidewall to form the second lordosis angle.

Claim 38

A cage according to claim 33 , wherein the second lordosis angle is 2°.

Claim 39

A cage according to claim 33 , wherein a center of the first inner radius of curvature is offset from a center of the second outer radius of curvature.

Claim 40

A cage according to claim 33 , wherein the first inner radius of curvature is 22 mm.

Claim 41

A cage according to claim 33 , wherein the second outer radius of curvature is between 18 mm and 26 mm.

Claim 42

A cage according to claim 33 , wherein the second outer radius of curvature is 19 mm.

Claim 43

A cage according to claim 33 , wherein the second outer radius of curvature is 21 mm.

Claim 44

A cage according to claim 33 , wherein the second outer radius of curvature is 23 mm.