Other

Joachim Theusner

Hans Nagerl

Dietmar Kubein-Meesenburg

Dieter Kubein-Meesenburg

Artificial joint, in particular endoprosthesis for replacing natural

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.

Artificial joint

Exoprosthesis for the human knee joint

Artificial joint to replace the human patella

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.

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. The joint head (3) and the joint pan (2) are arranged in relation to their functional surfaces such that in their position corresponding to the rest position of the arm in a dangling state the functional surfaces (5,7) have the same radius of curvature in the contact area (8) on both sides in the frontal plane with a linear contact of the functional surfaces (5,7), and such that a roll-off area (9) adjoins, in which the radii R.sub.P1, R.sub.K1 of both functional surfaces (5,7) are selected such that a circumferentially widening gap section covers the area between both joint parts (2,3).

Artificial joint as an endoprosthesis for the human shoulder joint

Artificial joint for replacing human joints in particular, consisting of at least two joint parts with spherical functional surfaces that can move relative to each other. 2 The curvature relationships of the functional surfaces having a circular cross-sectional contour are convex/convex, convex/concave or concave/concave relative to each other, and the geometric design of the joint is determined by a joint chain with two joint axes running through the centers of rotation M.sub.1 and M.sub.2 of the functional surfaces with radii R.sub.1 and R.sub.2, where R.sub.1 is the radius of the circular cross-sectional contour of the functional surface with center of rotation M.sub.1, and R.sub.2 is the radius of the circular cross-sectional contour of the functional surface with center of rotation M.sub.2.

Growing community of inventors

Klein-Lengden, Germany

Hans Nagerl