| abstract |
The invention relates to an endoprosthesis (11h) for a joint, in which the two cooperating parts (15h, 16h) of the joint are connected by a cord-like connecting piece (21h) which is fastened near the body axis (M2h, M2') of the convex articular head (15h), and extends along an oblong groove in the direction of flexion of the joint. The connecting piece guarantees a certain play (31h) between the two contact surfaces (19h, h', 20h, h') of the joint (11h). A projection (50h, 43h) in the concave joint part (16h) protects the connecting piece from friction at the groove wall (55h, 55h'). A projection (43h, 50h) in the concave joint part (16h) and a cavity (49h) in the convex joint part (15h) cooperate in such a way that the play of lateral motion between the cavity and the projection determines the freedom of motion of the lateral flexion of the joint. In an advantageous version of the invention, spherical surfaces guarantee that, when pressure is applied, at least one pair of corresponding sliding surfaces (19h, 20h; 19h', 20h') rest against each other on the two joint heads, in all positions of the joint. |