Intervertebral disc having translation

An intervertebral motion disc comprising:

• a) a prosthetic vertebral endplate comprising:
• i) an outer surface adapted to mate with a vertebral body,
• ii) an inner surface having a first opening thereon,
• iii) a body portion connecting the inner and outer surfaces and defining a sidewall comprising a second opening thereon, and
• iv) a first articulation surface suitable for supporting articulation motion,
• wherein the first and second openings communicate to form a channel having a first open end, and
• b) a core member having a first articulation surface suitable for supporting articulation motion,
• wherein the core member is disposed within the channel and oriented therein to produce a first articulation interface between the first articulation surface of the first endplate and the first articulation surface of the core member, and
• c) means for retaining the core member within the channel,
• wherein the means for retaining the core member within the channel comprises a tab shaped for insertion into the channel, wherein the tab is disposed within the channel,
• wherein the tab comprises a body portion and deformable arms extending from the body portion,
• wherein each deformable arm comprises a wing extending therefrom,
• wherein the body portion of the endplate further comprises second and third sidewalls defining a first width and the wings define a wingspan, and wherein the wingspan exceeds the first width of the channel, and
• wherein each of the second and third sidewall of the endplate further comprises a socket extending therein, thereby defining opposing sockets, and
• wherein the wings are shaped to be received within the opposing sockets.

An intervertebral motion disc comprising:

• a) a first prosthetic vertebral endplate comprising:
• i) an outer surface adapted to be attached to a first vertebral body,
• ii) an inner surface comprising an inner portion and a peripheral portion,
• wherein at least one of the portions comprises a first articulation surface, and
• b) a second prosthetic vertebral endplate comprising:
• i) an outer surface adapted to be attached to a second vertebral body,
• ii) an inner surface comprising an inner portion and a peripheral portion,
• wherein at least one of the portions comprises a first articulation surface, and
• c) a core member comprising:
• i) a first articulation surface adapted for articulation with the first articulation surface of the first endplate, and
• ii) a second articulation surface adapted for articulation with the first articulation surface of the second endplate,
• d) means for limiting the translation motion of the core member,
• wherein the core member is disposed between the endplates and oriented therein to produce a first articulation interface between the first articulation surface of the first endplate and the first articulation surface of the core member, and a second articulation interface between the first articulation surface of the second endplate and the second articulation surface of the core member, and a distance between the peripheral portions of the first and second endplates, and
• wherein the distance between the peripheral portions is greater than the height of the core member,
• wherein the means for limiting the translation motion of the core member comprises a tab shaped for insertion into the channel, wherein the tab is disposed within the channel,
• wherein the tab comprises a body portion and deformable arms extending from the body portion,
• wherein each deformable arm comprises a wing extending therefrom,
• wherein the body portion of the endplate further comprises second and third sidewalls defining a first width and the wings define a wingspan, and wherein the wingspan exceeds the first width of the channel, and
• wherein each of the second and third sidewall of the endplate further comprises a socket extending therein, thereby defining opposing sockets, and
• wherein the wings are shaped to be received within the opposing sockets.

An intervertebral motion disc comprising:

• a) a first prosthetic vertebral endplate comprising:
• i) an outer surface adapted to be attached to a first vertebral body, and
• ii) an inner surface comprising a first articulation surface,
• b) a second prosthetic vertebral endplate comprising:
• i) an outer surface adapted to mate with a second vertebral body, and
• ii) an inner surface having a first articulation surface,
• c) a core member comprising:
• i) a first articulation surface adapted for articulation with the first articulation surface of the first endplate, and
• ii) a second articulation surface adapted for articulation with the first articulation surface of the second endplate,
• d) means for limiting a motion of the core member,
• wherein the core member is disposed between the endplates and oriented therein to produce a first articulation interface between the first articulation surface of the first endplate and the first articulation surface of the core member, and a second articulation interface between the first articulation surface of the second endplate and the second articulation surface of the core member,
• wherein the first articulation interface has a range of anterior-posterior A-P motion and a range of medial-lateral M-L motion,
• wherein the range of A-P motion is between 1.5 and 50 times greater than the range of M-L motion,
• wherein the means for limiting the translation motion of the core member comprises a tab shaped for insertion into the channel, wherein the tab is disposed within the channel,
• wherein the tab comprises a body portion and deformable arms extending from the body portion,
• wherein each deformable arm comprises a wing extending therefrom,
• wherein the body portion of the endplate further comprises second and third sidewalls defining a first width and the wings define a wingspan, and wherein the wingspan exceeds the first width of the channel, and
• wherein each of the second and third sidewall of the endplate further comprises a socket extending therein, thereby defining opposing sockets, and
• wherein the wings are shaped to be received within the opposing sockets.