Abstract: The present invention concerns an artificial joint, in particular an endoprosthesis to replace natural joints, consisting of at least two artificial joint parts with curved articulation surfaces, wherein, on each of the articulation surfaces, a contact line (k) in the shape of the arc of a circle is formed, which is a section of a contact circle with a center (M), lying in a plane. The articulation surfaces are arranged as a pair with respect to one another in such a manner that the contact lines (k) can roll onto one another, and vertical to the plane of the contact circles, are intersected at an intersection point (S) by axes (m) passing through their center (M).

Abstract: Artificial joint, in particular an endoprothesis for the human knee joint, consisting of at least two joint parts moving with respect to each other, a joint head and a joint base, with toroidal joint surfaces, that have function surfaces with differing circular intersection contours in mutually perpendicular planes--a longitudinal plane and a transverse plane--whereby the curve ratios of the function surfaces are defined in each of the planes as either convex-convex, convex-concave, or concave-concave, and the joint geometry of the function areas to each other in each of the two planes is determined by a link chain with two link axes (dimeric link chain), which proceed through the rotation centers of the function areas with the radii of the attendant intersection contours, respectively.

Abstract: The present invention relates to an exoprosthesis for the human knee joint consisting of a thigh part (1) which can be connected to the human thigh as well as a lower leg part (6) which can be connected to the human lower leg or which can replace it. The lower leg part (6) and the thigh part (1) are connected through a four-bar arrangement which consists of two parallel arranged partial joints, specifically a medial joint (11) and a lateral joint (10) each of which has the joint geometry of a link chain with two articulated axles (M.sub.u, M.sub.o ; L.sub.o, L.sub.u) (dimer link chains). The joint geometry of the medial joint (11) is designed as an overlapping, dimer link chain in which the articulated axle M.sub.u of the lower leg part (6) is displaced in the direction towards the thigh part (1) with respect to the articulated axle M.sub.o of the thigh part (1) and the joint geometry of the lateral joint (10) is designed as an extended dimer chain in which the articulated axle L.sub.

Abstract: Artificial joint, especially endoprosthesis for the human patella joint, consisting of two joint bodies which move with respect to one another, one joint body (1) with two coincidental joint heads (2,3) and one joint body (6) with two coincidental joint sockets (7,8) which in each case have toroid joint surfaces (4,5; 9,10) which have functional surfaces (4,5; 9,10) which have a longitudinal plane and a corresponding transverse plane, in planes which are vertical with respect to one another, of differing, circular section contours. The curvature relationships of the functional surfaces (4,5; 9,10) are either concave-convex or convex-convex in each of the planes.

Abstract: Artificial joint, in particular an endoprothesis for the human knee joint, consisting of at least two joint parts moving with respect to each other, a joint head and a joint base, with toroidal joint surfaces, that have function surfaces with differing circular intersection contours in mutually perpendicular planes--a longitudinal plane and a transverse plane--whereby the curve ratios of the function surfaces are defined in each of the planes as either convex--convex, convex-concave, or concave--concave, and the joint geometry of the function areas to each other in each of the two planes is determined by a link chain with two link axes (dimeric link chain), which proceed through the rotation centers of the function areas with the radii of the attendant intersection contours, respectively.

Abstract: The invention at hand concerns an artificial joint, in particular an endoprosthesis for a human shoulder joint, consisting of two parts, a joint head (3) and a joint pan (2) with spherical joint surfaces moving relative to one another. The bending conditions of the functional surfaces (5,7) are convex-concave in the frontal plane as well as in the perpendicular transverse plane. The joint geometry of the functional surfaces towards each other in both planes is determined through a dimeric joint chain which runs through the rotation centers of the functional surfaces of each of the intersection contours.