Patent ID: 6517580
Filing Date: 2003-02-11
Classification: A61F

Abstract:
A disk prosthesis for cervical vertebrae, the prosthesis being of the type comprising:first and second plates designed to be fixed to adjacent cervical vertebrae; and a ball joint interposed between the two plates mounted in a superposed position, the joint being constituted by a spherical cap co-operating with a spherical cup, wherein: the spherical cap is provided on a first insert, while the spherical cup is provided on a second insert; each insert is made of a ceramic material and possesses a base of circular right cross-section; one of the inserts is mounted on the first plate while the other insert is mounted on the second plate in such a manner that the center of rotation of the joint lies substantially centered relative to the edges of the plates so as to be centered in the sagittal plane and in the frontal plane of the vertebrae; the spherical cup possesses a contact area that is not less than the contact area of the spherical cap and is connected via an annular molding to the base of the insert; and the plate provided with the insert having the spherical cap has an annular setback to leave clearance for the annular molding of the spherical cup during movements of the plates.