Centrally articulating spinal device and method

1 . An artificial spinal joint for creating at least a portion of a coupling between a superior vertebra and an inferior vertebra comprising:

an articulating joint replacement assembly comprising an anterior joint replacement component for placement into an intervertebral disc space between the superior and inferior vertebrae, a first posterior joint replacement component, and a first bridge component coupled between the anterior joint replacement component and the first posterior joint replacement component; and

a support joint replacement assembly comprising an anterior support component for placement into an intervertebral disc space between the superior and inferior vertebrae, a second posterior joint replacement component, and a second bridge component coupled between the anterior support component and the second posterior joint replacement component,

wherein the anterior support component is adapted for engagement with the anterior joint replacement component.

2 . The artificial spinal joint of claim 1 wherein the anterior joint replacement component comprises a convex wall and the anterior support component comprises a convex wall, further wherein the convex wall is slidably engaged with the concave wall.

3 . The artificial spinal joint of claim 1 wherein the anterior joint replacement component includes a first connecting mechanism and the anterior support component includes a second connecting mechanism, further wherein the first connecting mechanism attaches to the second connecting mechanism.

4 . The artificial spinal joint of claim 3 wherein the first connecting mechanism includes a slot and the second connecting mechanism includes a tab and further wherein the tab is adapted for insertion into the slot.

5 . The artificial spinal joint of claim 3 wherein the first connecting mechanism includes a threaded recess and the second connecting mechanism includes a threaded post.

6 . The artificial spinal joint of claim 1 wherein the anterior support component is movably engaged with the anterior joint replacement component.

7 . The artificial spinal joint of claim 1 wherein the first bridge component extends posteriorly from the anterior joint replacement component and outwardly of the intervertebral disc space.

8 . The artificial spinal joint of claim 1 wherein the anterior joint replacement component includes a rostral anterior component engaged with a caudal anterior component.

9 . The artificial spinal joint of claim 8 wherein the first bridge component comprises a rostral bridge extending from the rostral anterior component.

10 . The artificial spinal joint of claim 9 wherein the rostral bridge component comprises a jog adapted to permit passage of a neural element.

11 . The artificial spinal joint of claim 8 wherein the first bridge component comprises a caudal bridge extending from the caudal anterior component.

12 . The artificial spinal joint of claim 1 wherein the first posterior joint replacement component comprises:

a rostral posterior component, wherein the rostral posterior component includes a posterior socket and

a caudal posterior component, wherein the caudal posterior component includes a posterior articulating portion,

wherein the posterior articulating portion is adapted to articulate with the posterior socket.

13 . The artificial spinal joint of claim 12 further comprising a fastener, wherein the posterior articulating portion comprises an aperture and the fastener is adapted for insertion through the aperture into the superior or inferior vertebrae and further wherein at least a portion of the fastener is adapted to articulate with the posterior socket.

14 . The artificial spinal joint of claim 13 wherein the posterior socket comprises a slot and wherein the fastener is adapted to articulate within the slot.

15 . The artificial spinal joint of claim 13 wherein the fastener is a bone screw.

16 . The artificial spinal joint of claim 1 further comprising a bone fastener for attaching the artificial spinal joint to either the superior vertebra or the inferior vertebra.

17 . The artificial spinal joint of claim 16 wherein the posterior joint replacement component comprises a connection component adapted to receive the bone fastener.

18 . The artificial spinal joint of claim 17 wherein the bone fastener is a bone screw and the connection component is further adapted to direct the received bone screw for extrapedicular connection to the inferior vertebra.

19 . The artificial spinal joint of claim 17 wherein the bone fastener is a bone screw and the connection component is further adapted to direct the received bone screw into a generally cylindrical body portion of the superior vertebra.

20 . The artificial spinal joint of claim 1 wherein the anterior joint replacement component includes a curved protrusion engaged with an anterior socket.

21 . The artificial spinal joint of claim 1 wherein the anterior joint replacement component is sized for insertion through Kambin's triangle.

22 . The artificial spinal joint of claim 1 wherein the first bridge component is at least a portion of an artificial pedicle.

23 . A method of implanting an artificial spinal joint, the method comprising:

creating a first exposure through a patient's back to access an intervertebral space;

creating a second exposure through the patient's back to access the intervertebral space;

delivering an articulating assembly portion of the artificial spinal joint to the intervertebral space along a first path through the first exposure;

delivering a support assembly portion of the artificial spinal joint to the intervertebral space along a second path through the second exposure; and

engaging the articulating assembly portion with the support assembly portion,

wherein the first exposure provides a first minimum clearance for the articulating assembly portion and the second exposure provides a second minimum clearance for the support assembly portion and

wherein the first exposure is larger than the second exposure.

24 . The method of claim 23 wherein the first path is curved.

25 . The method of claim 23 wherein the second path is contralateral to the first path.

26 . The method of claim 23 wherein the articulating assembly portion includes a recess and the support assembly includes a tab and wherein engaging the articulating assembly portion includes inserting the tab into the recess.

27 . The method of claim 23 wherein engaging the articulating assembly portion with the support assembly portion includes threadedly engaging the articulating assembly portion with the support assembly portion.

28 . The method of claim 23 wherein engaging the articulating assembly portion with the support assembly portion includes pivotally engaging a convex wall of the articulating assembly portion with a concave wall of the support assembly portion.

29 . The method of claim 23 further comprising:

positioning a first posterior joint portion of the artificial spinal joint outside of the intervertebral space,

wherein the first posterior joint portion is connected to the articulating assembly portion and wherein positioning a first posterior joint portion includes engaging a posterior articulating surface of the first posterior joint portion with a posterior socket of the first posterior joint portion.

30 . The method of claim 29 wherein positioning the first posterior joint portion further includes restricting displacement of the posterior articulating surface within the posterior socket to restrict rotational movement in the articulating assembly portion.

31 . The method of claim 29 wherein positioning the first posterior joint portion further includes restricting displacement of the posterior articulating surface within the posterior socket within a predetermined range to limit flexion-extension movement in the articulating assembly portion.

32 . The method of claim 29 wherein positioning the first posterior joint portion further includes restricting displacement of the posterior articulating surface within the posterior socket to limit lateral bending movement in the articulating assembly portion.

33 . The method of claim 29 further comprising:

positioning a second posterior joint portion of the artificial spinal joint outside of the intervertebral space,

wherein the second posterior joint portion is connected to the support assembly portion.

34 . The method of claim 23 wherein the step of delivering an articulating assembly portion includes engaging a rostral concave surface of the articulating assembly portion with a caudal convex surface of the articulating assembly portion.

35 . The method of claim 23 wherein the step of inserting includes inserting at least a portion of the articulating assembly portion through Kambin's triangle.

36 . A system for creating a coupling between a superior vertebra and an inferior vertebra, the system comprising:

an anterior articulating assembly for implantation through a first approach into an intervertebral disc space between the superior and inferior vertebrae and

a first posterior articulating assembly connected to the anterior articulating assembly and extending posteriorly of the intervertebral disc space, wherein the anterior articulating assembly comprises a caudal articulating surface engaged with a rostral articulating surface wherein the engagement of the caudal and rostral articulating surfaces defines a center of rotation, further wherein

the center of rotation lies generally along a central anterior-posterior axis through the intervertebral disc space.

37 . The system of claim 36 further comprising:

a rigid bridge assembly connecting the anterior articulating assembly and the first posterior articulating assembly.

38 . The system of claim 36 further comprising:

a support assembly for implantation through a second approach, wherein the second approach is contralateral to the first approach, into the intervertebral disc space to engage the anterior articulating assembly.

39 . The system of claim 38 wherein the support assembly comprises a concave wall for engaging a convex wall of the anterior articulating assembly.

40 . The system of claim 38 wherein the support assembly comprises a tab for engaging a recess of the anterior articulating assembly.

41 . The system of claim 38 wherein the support assembly is threadedly engaged with the anterior articulating assembly.

42 . The system of claim 38 wherein the support assembly further comprises a second posterior articulating assembly extending posteriorly of the intervertebral disc space.

43 . A method of implanting an artificial spinal joint, the method comprising:

creating a first exposure through a patient's back to access an intervertebral space;

positioning a first portion of the artificial spinal joint in the intervertebral space wherein the first portion comprises a rostral articulating component and a caudal articulating component;

centering a center of rotation between the rostral articulating component and the caudal articulating component along an anterior-posterior axis defined through the intervertebral space; and

positioning a second portion of the artificial spinal joint posteriorly of the intervertebral space,

wherein the first and second portions are rigidly connected.

44 . The method of claim 43 wherein the first exposure is a transforaminal exposure.

45 . The method of claim 43 wherein the first exposure is a posterior exposure.

46 . The method of claim 43 further comprising:

creating a second exposure through a patient's back to access the intervertebral space;

positioning a third portion of the artificial spinal joint in the intervertebral space wherein the third portion comprises a support component; and

connecting the support component to at least one of the rostral or caudal articulating components.

47 . The method of claim 46 wherein the support component comprises a rostral support component and a caudal support component and wherein the step of connecting further comprises connecting the rostral support component to the rostral articulating component and connecting the caudal support component to the caudal articulating component.

48 . The method of claim 46 further comprising:

positioning a fourth portion of the artificial spinal joint posteriorly of the intervertebral space,

wherein the third and fourth portions are rigidly connected.

49 . An artificial spinal joint for creating at least a portion of a coupling between a superior vertebra and an inferior vertebra comprising:

an anterior joint replacement component extending into an intervertebral disc space between the superior and inferior vertebrae;

a bridge component coupled to the anterior joint replacement and extending posteriorly from the anterior joint replacement beyond the intervertebral disc space; and

a posterior joint replacement component coupled to the bridge, wherein the posterior joint replacement component includes a posterior protrusion engaged with a posterior socket,

wherein the bridge and the posterior joint replacement component are adapted to be positioned on a single lateral side of a laterally centralized, anterior-posterior axis defined between the superior and inferior vertebrae.

50 . The artificial spinal joint of claim 49 wherein the anterior joint replacement component defines a center of rotation and wherein the center of rotation is positioned along the anterior-posterior axis.

51 . The artificial spinal joint of claim 49 wherein the anterior joint replacement component defines a center of rotation and wherein the center of rotation is positioned to the single lateral side.

52 . A system for creating at least a portion of a coupling between a superior vertebra and an inferior vertebra comprising:

a first means adapted for articulation in an intervertebral disc space between the superior and inferior vertebrae;

a second means adapted for articulation posteriorly of the intervertebral disc space;

a third means for coupling between the first means and the second means; and

a fourth means for supporting the first means in the intervertebral disc space.