Patent ID: 8043379

Claim:
An intervertebral disc prosthesis configured for insertion between a superior vertebral body and an inferior vertebral body, the intervertebral disc prosthesis comprising: a first endplate including a first upper vertebra facing surface and a concave articulating surface; a second endplate including a second lower vertebra facing surface and a convex articulating surface; and a bearing component positioned between the first endplate and the second endplate, the bearing component including (i) a convex bearing surface configured to engage the concave articulating surface of the first endplate and (ii) a concave bearing surface configured to engage the convex articulating surface of the second endplate, wherein the concave bearing surface of the bearing component and the convex articulating surface of the second endplate form a first contact pair and define a flexion/extension center of rotation for the bearing component, and wherein, when the intervertebral prosthesis is viewed in a side cross-sectional view in which (i) the second lower vertebra facing surface defines a left lower plate end and a right lower plate end, (ii) a region in the cross-sectional view is defined between a first vertical plane tangent to the left lower plate end and a second vertical plane parallel to the first plane and tangent to the right lower plate end, (iii) an entire cross-section of the bearing component is located within the region, (iv) an entire cross-section of the concave bearing surface is directly beneath the first upper vertebra facing surface, and (v) an entire cross-section of the convex bearing surface is directly above the second lower vertebra facing surface, the flexion/extension center of rotation for the bearing component is outside of the region.