Abstract: In order to allow a knee-joint orthesis which is equipped with mounting structure for both the thigh and lower leg to take over the physiological movement of the knee-joint as precisely as possible, it is foreseen in accordance with the invention to connect the respective mounting structure pivotably by two intermediate rotation elements, whereby at least one rotation element includes a center of rotation which is displaceable relative to the mounting structures. The other rotation element includes preferably a center of rotation which is fixed relative to the mounting structures, and this rotation element is preferably arranged at the medial side of the knee-joint. Rotation elements with a displaceable center of rotation are designed preferably in form of a cross-over quadruple joint. The rotation element which possibly includes a fixed axis of rotation is formed preferably by a ball and socket joint.

Abstract: The vertebrae implant has a stabilizing element which is articulated to a pair of bone screws so as to accommodate skew positions of the bone screws relative to each other. A slotted clamp is provided to secure the stabilizing element to each bone screw. In addition, each clamp is disposed between a shoulder having a spherical surface and a clamping nut. A washer is also disposed between the clamping nut and the clamp. The clamping nut and/or washer is provided with a spherical surface to provide for pivoting of the clamp relative to the bone screw prior to tightening of the clamping nut.