INTERVERTEBRAL SPACER DEVICE
An intervertebral spacer device includes a first plate and a second plate, each plate having an outer surface for seating against opposing vertebral bone surfaces. The device includes a ball captured in a central opening of a coupling element, the coupling element being maintained against the first plate by a retaining ring coupled with the first plate.
1 . An intervertebral spacer device for insertion into an intervertebral space comprising:
first and second members disposed in a spaced apart relationship such that inner surfaces of the first and second members oppose one another;
a resilient element articulably coupled to the second member; and
a retaining ring attached to the first member to hold the resilient element against the inner surface of the first member.
2 . The device of claim 1 , wherein the resilient element has a radially varying thickness such that the resilient element has a non-linear load deflection profile after the intervertebral spacer device is fully assembled for insertion into the intervertebral space.
3 - 4 . (canceled)
5 . The device of claim 1 , wherein the second member further comprises a post to which the resilient element is articulably coupled, the post extending from the inner surface thereof.
6 . The device of claim 1 , wherein the post further includes a threaded bore which extends axially from the ball shaped head toward the inner surface of the second member, and which receives therein a threaded set screw such that, prior to insertion of the set screw therein, the bore permits the ball-shaped head to compress radially inwardly.
7 . The device of claim 15 , wherein the resilient element further comprises a central opening which defines a curvate volume for receiving and holding therein the ball-shaped head.
8 . The device of claim 1 , wherein the first and second members are base plates.
9 . The device of claim 1 , wherein at least one of the first and second members include a porous coating on an outer surface thereof to facilitate bone in-growth.
10 . The device of claim 1 , wherein the first member at least partially encloses the resilient element.
11 . The device of claim 10 , wherein the first member includes a retaining wall extending therefrom, and wherein the retaining ring is attached to and is at least partially enclosed by the retaining wall.
12 . The device of claim 1 , wherein the retaining ring is attached to the inner surface of the first plate member by a retaining wall.
13 . The device of claim 1 , wherein the resilient element is movable toward or away from the first member after the intervertebral spacer device is fully assembled for insertion into the intervertebral space.
14 . The device of claim 1 , wherein the resilient element is a Belleville washer having a concave surface that contacts the first member to hold the Belleville washer against the inner surface of the first member.
15 . The device of claim 5 , wherein the post includes a ball-shaped head.
16 . The device of claim 6 , wherein, after the insertion of the set screw, the ball-shaped head is not readily radially compressible.
17 . The device of claim 1 , wherein the resilient element is a slotted washer.
18 . An intervertebral spacer device for insertion into an intervertebral space comprising:
first and second plate members disposed in a spaced apart relationship such that inner surfaces of the first and second plate members oppose one another;
a Belleville washer coupled to the second member; and
a retaining ring attached to the first plate member to hold the Belleville washer against the inner surface of the first plate member.
19 . The device of claim 18 , wherein the first plate member includes a retaining wall extending therefrom, and wherein the retaining ring is attached to and is enclosed by the retaining wall.
20 . The device of claim 18 , wherein the second plate member further comprises a post to which the Belleville washer is articulably coupled, the post extending from the inner surface thereof and including a ball-shaped head.
21 . The device of claim 20 , wherein the post further includes a threaded bore which extends axially from the ball-shaped head toward the inner surface of the second member and which receives therein a threaded set screw such that, prior to insertion of the set screw therein, the bore permits the ball-shaped head to compress radially inwardly.
22 . The device of claim 20 , wherein the Belleville washer further comprises a central opening which defines a curvate volume for receiving and holding therein the ball-shaped head.