Orthopaedic medical device

Abstract

An artificial disc having a pair of opposing plates () for seating against opposing vertebral bone surfaces separated by an inner stress distributor and spacer device () called in this specification a supporting element, functioning as both a spacer and structural support. Various plate geometries are disclosed including ones with flat outer faces and ones with convex outer faces to conform to the adjacent vertebral mating surface geometry. Inner surfaces are described as comprising two sloping substantially flat or curved surfaces meeting at an ridgeline with a radius. Various inner device embodiments are disclosed including circular ones and non-circular ones, plate flat ones, ones with a raised rim or circular recess, ones with raised hubs and ones with an elastomeric planar core to perform a shock-absorbing function, ones with central bore and ones with no central bore. Inner spacers comprising various combinations of these features are disclosed. The inner spacer/support devices are dispersed between the plates, through various disclosed couplings, so that the plates compress, rotate and angulate freely relative to one another, enabling the artificial disc to mimic a healthy natural intervertebral disc.