INTERVERTEBRAL PROSTHESIS

摘要

An intervertebral prosthesis for insertion between adjacent vertebrae includes upper and lower prosthesis plates locatable against respective vertebrae and having opposing, concavely curved recesses therein, and a core located between the plates. The core has opposed, convexly curved surfaces received in the recesses of the plates to allow the plates to slide in articulated manner over the core. The opposed surfaces of the core and the recesses of the plates have cooperating spherical curvatures. The recess of each plate surrounds a locating peg projecting centrally from the base of the recess and is bounded by an annular rim, such that the annular rims of the plates are arranged to contact one another at a predetermined limit of sliding movement of the plates over the core. The peg locates loosely in an opening located centrally in a curved surface of the core, whereby the plates can slide over the core in all directions while the peg holds the core captive.

主权项

1. A method comprising:
providing a prosthesis comprising: upper and lower prosthesis plates having at least one upstanding elongate projection, the upper prosthesis plate having a concavely curved, spherical bearing surface therein; a moveable core having a convexly curved, spherical surface configured to cooperate with the concavely curved surface of the upper plate, wherein the upper and lower plates are able to both translate and rotate with respect to each other and with respect to the core, and a protrusion on at least one of the plates and corresponding opening on the core which hold the core captive and prevent the core from slipping out sideways from between the plates; and implanting the prosthesis between adjacent vertebrae.