Extradiscal intravertebral prosthesis for the control of intervertebral distance variations by means of a double damper

Abstract

Abstract Damper (shock-absorber), of the type comprising: (1) an elastic body whose volume is less than that of the chamber defined by the free position of the piston with respect to the bottom of the cylinder, consisting of the elements (1 or 1' or 10 or 10') (2) a hollow cylinder (1a) pierced with a through slot (1d), one of the ends of which cylinders is closed by a bottom (1b) which is integral on its outer face with a tenon (1c), while the other end receives a disc (2) which allows, by means of an assembly ring (3), connection with another element (1), a sleeve (4) placed in the cylinder (1), one of the ends of which sleeve is closed by a bottom (4a) while the other receives a face of the disc (2), on which face a boss (2a) is provided, a notch (4b) being made on the periphery of the sleeve (4) and a screw (5) whose spherical head (5a) is pivotally mounted between the disc (2) and the bottom (4a), and an elastic body (7) placed between the sleeve (4) and the bottom (2b) of the cylinder (1) so as to damp the displacements of this cylinder under the effect of the displacements of the screw, in order to regulate the movement between two vertebrae so as to match the physiological appearance of a disc movement as closely as possible. <IMAGE>

Inventors

• 👤 Fernand Navas

Bibliographic Details