US Patent 7147665 Threaded cylindrical multidiscoid single or multiple array disc prosthesis

A small profile, cylindrically shaped prosthetic disc device is provided. The device housing is comprised of two longitudinally split hollow halves, between which are contained multiple discoid shaped resilient bodies which may be of a polymeric type, or they may contain hydrogel. These bodies may lie in concave surfaces located on the interior of each side of the split cylindrical housing. The housing halves even under maximum physiological loads, do not contact one another directly. Threads on the exterior surface of the cylindrical housing facilitates insertion and retention in the prepared bone opening.