Spring and spherical joint artificial disc replacements

摘要: One or more springs in an artificial disc replacement (ADR) provide natural movement and extend life of the spring ADR. In preferred embodiment, articulate with at least one convex concave surface on endplate (EP) More particularly, may with, connect to, articulating EP components. various alternative embodiments, ADR EPs include features that impinge otherwise limit maximum load a multiple springs. The be disposed cylinders, over posts, constrained. For example, posts surfaces corresponding components, surfaces, EPs. Also, center rotation (COR) preferably spherical joint vary vertically by compression expansion compressible component. Alternatively, multiple, separate CORs cooperate simultaneously to form ‘combined COR’ for