Hjs Gelenk System Gmbh

Joachim Theusner

Dietmar Kubein-Meesenburg

Hans Naegerl

Peter Adam

An artificial joint (), particularly for replacing a talocrural joint, including a first primary joint surface () that forms an articular fossa () particularly for replacing the tibia composed of concave curvatures extending parallel to a primary function plane of the joint (), which corresponds to the sagittal plane, and a second primary joint surface () which cooperates with the first primary joint surface () as a component of a condoyle () that replaces the talus and has convex curvatures () on the primary function plane that are adapted to the first primary joint surface (). To achieve high stress resistance and optimal joint mobility, depending on the position of the joint, the radii of the curvatures () are calculated such that the differential amounts arising between the corresponding radii of the first and second primary joint surfaces () in an ascending angular position (V) relative to a descending angular position and also simultaneously between a medial face () and a lateral face () of the joint () deviate from one another.

Artificial joint

An artificial joint () suitable for use as an endoprosthesis for a human knee joint, having a first joint compartment () formed by a first condyle () and a first socket () and a second joint compartment () formed by a second condyle () and a second socket (). The contact surfaces (C) of the respective joint compartments () are offset in the main functional plane. To further improve the characteristics of the artificial joint (), the contact surfaces (C) of the two joint compartments () are sloped as a function of the flexion angle such that the surface normals () of the contact surfaces (C) have a common point of intersection at every flexion angle. This arrangement of the contact surfaces (C) achieves self-stabilization of the joint () both when a rotary motion or torsion and when lateral forces are introduced.

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Munich, Germany

Joachim Theusner