Patent ID: 8118869

Claim:
A system comprising a dynamic interbody device for a human spine, the device comprising: a first member configured to couple to an endplate of a first vertebra, the first member comprising a first inferior surface configured to couple to the first vertebra, and a first superior surface; and a second member configured to couple to an endplate of a second vertebra and the first member, the second member comprising a second superior surface configured to couple to the second vertebra and a second inferior surface, wherein the second member comprises an upper portion and a lower portion, and wherein one of the lower portion or the upper portion comprises two coupling protrusions, and the other of the lower portion and the upper portion comprises two substantially complementary coupling slots configured to engage the coupling protrusions during use such that the lower portion and the upper portion are coupled; wherein one of the first superior surface and the second inferior surface comprises a convex curvature and the other of the first superior surface and the second inferior surface comprises a concave curvature shaped substantially complementary to the convex curvature, wherein one of the first superior surface and the second inferior surface comprises a substantially elongated slot extending in a substantially lateral direction, and the other of the first superior surface and the second inferior surface comprises a substantially complementary protrusion configured to engage the slot to substantially guide lateral movement of the first member relative to the second member during use, wherein the first superior surface is configured to slide laterally along at least a portion of the second inferior surface during use, and wherein engagement of the protrusion with the slot substantially guides the lateral sliding of the first superior surface and the second inferior surface relative to one another such that the first and second members move substantially laterally relative to one another during use to allow for substantially lateral movement of the first vertebra relative to the second vertebra during use.