Abstract: The invention relates to a postero-lateral intervertebral disc prosthesis characterised in that: the insert (1) has a fixed planar section on the lower vertebral plateau, the element (3) has a lower planar surface for support on the insert (1) with a limited capacity for translational displacement and an upper surface with a generally hemispherical form, the insert (2) has a fixed planar section on the upper vertebral plateau and opposite thereto, a concave surface for cooperating with the hemispherical surface of the element (3), with the possibility of multi-directional articulation. The inserts (1) and (2) and the insert (3) are in the form of a disc with a diameter of less than about 30 mm and, when juxtaposed, define a total height of about 11 to 15 mm to permit introduction by an initially postero-lateral route.

Abstract: This hip prosthesis includes a femoral stem (3), a spherical head (6) designed to fit over a neck (5) of the femoral stem, and a metal socket (1) in which the head can articulate; a cup (7) is inserted between the head (6) and the socket, the head and the cup being made of ceramic or similar material having a low coefficient of friction, the head being articulated on the cup; the cup itself is articulated in a plastic socket (8) fixed in the metal socket (1). This prosthesis thus comprises a double articulation, on the one hand between its head (6) and the cup (7), and on the other hand between the cup (7) and the polyethylene socket (8), the first ceramic-ceramic articulation being the one principally stressed. For this reason, the wear of the polyethylene socket (8) produces extremely little debris, which considerably reduces the risks of separation and very substantially prolongs the total lifetime of the prosthesis. This prosthesis has low-wear properties.

Abstract: A prosthesis including (a) a flexible ligament (1) with a first narrowed thinner portion (2) and a second wider portion (3) forming an extension of, and having a greater width and thickness (e2) than, the first portion, which portion may be passed around the spinous processes (12) of two adjacent vertebrae (L5, L4) in a figure eight pattern, whereas the second portion circles around the processes; (b) a semi-flexible interprocess block (6) with two pairs of through-channels (7, 8) having differing cross-sections and receiving the respective portions of the ligament; and (c) members (4, 5) for joining the ends of the ligament. The prosthesis prevents sagittal and frontal lumbar vertebral rotational instability.