Abstract: The present invention relates to an intervertebral disc prosthesis preferably comprising at least three pieces including an upper plate (1), a lower plate (2) and a mobile core (3) at least in relation to the lower plate (2), co-operation means (23, 33) allowing to limit or eliminate the movements of the core (3) in relation to the lower plate (2), in translation and in rotation, respectively, about an axis substantially parallel to the lower plate (2) and about an axis substantially perpendicular to the lower plate (2), at least one part of the surface of at least one plate being concave and complementary with a convex surface (30) of the core (3), with which it is in contact, wherein the tip (31) of the convex surface (30) of the core (3) is off centre, in at least one direction, in relation to the centre (32) of this convex surface (30).

Abstract: An intervertebral disc prosthesis designed to be substituted for fibrocartilaginous discs ensures a connection between the vertebra of the vertebra column or the end of the latter. The prosthesis includes a pair of plates spaced from each other by a nucleus. The prosthesis has increased stability by providing the nucleus with a translation or rotation stop, or by inducing an angular correction between its plates contacting vertebra, or a combination of these characteristics. The stop includes parts external to the nucleus and contact surfaces perpendicular to their contact directions.

Abstract: An intervertebral cage includes a thin main wall having two return parts at opposite ends of the wall. The wall has an approximately constant thickness. The return parts are extended by facing end parts having a gap between them. The wall, the return parts and end parts delimit an inner cavity. The gap extends parallel to the wall and has a length between 50% and 100% of the cavity length. The gap length is preferably between 70% to 90% of the cavity length.

Abstract: An intervertebral cage includes a thin main wall having two return parts at opposite ends of the wall. The wall has an approximately constant thickness. The return parts are extended by facing end parts having a gap between them. The wall, the return parts and end parts delimit an inner cavity. The gap extends parallel to the wall and has a length between 50% and 100% of the cavity length. The gap length is preferably between 70% to 90% of the cavity length.

Abstract: The present invention relates to an osseous anchoring device intended to maintain a prosthesis or an implant in position, and in particular an anchoring device for an intervertebral prosthesis. The anchoring device for a prosthesis (1), or an implant, is intended to be anchored in a prepared osseous surface (310, 321). It comprises at least one protruding element extending beyond the prosthesis, this protruding element being able to be positioned relative to the prosthesis in a plurality of positions thus making it possible to choose a position adapted to the case to be treated or to the chosen mode of inserting the prosthesis or the anchoring device.

Abstract: An intervertebral nucleus prosthesis characterized in that it consists of at least one, in particular, spherical body movable in two directions of a plane and made of a rigid, non-oxidizing, biocompatible material with a diameter adapted to the biological nucleus, the spherical body being mounted non-displaceably but freely rotatably about its center in a cage and protruding at both opposite sides of said cage in the form of a spherical caps. Also proposed is a method for implanting such a prosthesis.