ARTIFICIAL DISC REPLACEMENT DEVICE
An artificial disk replacement device includes opposing plate members with a pivoting assembly disposed therebetween. The pivoting assembly allows the plate members to pivot relative to each other in a first direction, but inhibit movement of the plate members in a second direction. The plate members may be installed prior to installing the pivoting assembly. An installation tool for use with the artificial disk replacement device is also disclosed.
1 . An intervertebral implant comprising:
a first plate member;
a second plate member; and
a coupling disposed between the first plate member and the second plate member, the coupling adapted to allow the first plate member to pivot relative to the second plate member about a first axis extending through the coupling and inhibiting the first end plate from rotating relative to the second plate member about a second axis that is transverse to the first axis.
2 . The intervertebral implant of claim 1 , wherein the first plate member and the second plate member are adapted for engaging opposing vertebral endplates.
3 . The intervertebral implant of claim 1 , wherein the coupling includes:
a support member having a substantially hemispherical dome and a pair of opposing arms extending therefrom, and
a cup adapted for operative engagement with the support member, the cup having a complementary substantially hemispherical configuration and a pair of opposed openings configured to slidably engage the pair of opposing arms such that the cup is movable relative to the support member in a first direction and is inhibited from moving relative to the support member in a second direction that is orthogonal to the first direction.
4 . The intervertebral implant of claim 1 , wherein the coupling includes:
a support member having a substantially asymmetric dome and a pair of opposing arms extending therefrom, and
a cup adapted for operative engagement with the support member, the cup having a complementary substantially asymmetric configuration and a pair of opposed openings configured to slidably engage the pair of opposing arms such that the cup is movable relative to the support member in a first direction and is inhibited from moving relative to the support member in a second direction that is orthogonal to the first direction
5 . The intervertebral implant of claim 1 , further including at least one engaging member for attaching the coupling to at least one of the first and second plate members.
6 . The intervertebral implant of claim 2 , wherein the first and second plate members include a plurality of extensions, each extension adapted to frictionally engage the endplate of a vertebral body.
7 . A method of installing an intervertebral implant comprising the steps of:
providing a distraction device having a jaw assembly with a pair of movable blades;
attaching a first plate member to one of the movable blades and a second plate member to the other of the movable blades;
inserting the first plate member and the second plate member attached to the distraction device between adjacent vertebral bodies;
operating the distraction device to spread apart the adjacent vertebral bodies with the first plate member in contact with one vertebral body and the second plate member in contact with the other vertebral body;
inserting a coupling into a space between the first plate member and the second plate member;
forming the intervertebral implant by securing the coupling to the first end plate and the second end plate; and
removing the distraction device such that the first plate member and the second plate member engage opposing sides of the coupling and the coupling.
8 . The method of claim 7 , wherein the step of inserting the coupling includes the coupling having a support member operably coupled to a cup such that the cup is movable relative to the support member in a first direction and inhibited from moving relative to the support member in a second direction.
9 . The method of claim 7 , wherein the step of inserting the coupling further includes the support member having a substantially hemispherical surface with a pair of opposing arms extending therefrom and the cup including a complementary configuration with a pair of opposed openings that are adapted for rotatably engaging the arms.
10 . The method of claim 7 , wherein the step of inserting the coupling further includes the support member having a substantially asymmetric surface with a pair of opposing arms extending therefrom and the cup including a complementary configuration with a pair of opposed openings that are adapted for rotatably engaging the arms