Abstract: A rotation-symmetrical articulation chamber is formed in the shaft head of an endoprosthesis. An axial articulation member is disposed in this chamber. The articulation member axis and the axis of rotation are perpendicular relative to each other. A joint neck can be pivoted about the axis of rotation and the articulation member axis at any selected angle of inclination or rotation. Clamping surfaces that are disposed at an angle to the axis of rotation are rotation-symmetrical or planar and interact with articulation surfaces of the articulation member that can also be rotation-symmetrical.

Abstract: In a joint prosthesis with a base piece for anchoring in the bone, a collar piece articulated thereon and defining a collar axis, and a collar extension on the collar piece situated on the collar axis, an articulation space is formed on the base piece. An articulation head of the collar piece is disposed therein. The joint prosthesis further includes a head cap disposed on the collar extension and at least one pressure piece for pressing the articulation head against the base of the articulation space. The pressure piece and the base piece can be connected. In a joint prosthesis of this kind, the pressure piece includes a pressure disc with a passage opening for the collar extension.

Abstract: A joint prosthesis is disclosed which includes an articulation cavity for an articulation body, in a head section of a base part. The position of the articulation body used in the articulation cavity defines the subsequent collar axis for an articulation part mounted on the articulation body. The articulation cavity has a tapering lateral surface which co-operates with an articulation surface that is symmetrical to a pivoting axis. The articulation surface has a circular edge. In an cutting plane perpendicular to the pivoting axis, which passes through the contact point between lateral surface and the circular edge, the radius of the circular edge is larger than the radius at the vertex circle of the cutting curve between the cutting plane and the lateral surface. Two contact points can thus be created between the circular edge and the lateral surface, said contact points being located on different sides of a plane containing the rotation axis and the pivoting axis.

Abstract: In a joint prosthesis the head cap is connected via a collar piece to the shaft piece which may be anchored in the bone. The collar piece is coupled to the shaft piece by a joint head in a ball-jointed manner. The articulation surfaces between the joint cavity in the shaft piece and the articulation head on the collar piece are embodied such that on pressing the articulation head to the base of the joint cavity, edges or projections on the one articulation surface digs into the other articulation surface lying on a virtual spherical surface. It is thus possible to achieve a ball-joint like articulation, whereby the spherical surfaces may have a relatively large production tolerance without the above affecting the clamping connection between the articulation surfaces.

Abstract: In a joint prosthesis with a base piece for anchoring in the bone, a collar piece articulated thereon and defining a collar axis, and a collar extension on the collar piece situated on the collar axis, an articulation space is formed on the base piece. An articulation head of the collar piece is disposed therein. The joint prosthesis further includes a head cap disposed on the collar extension and at least one pressure piece for pressing the articulation head against the base of the articulation space. The pressure piece and the base piece can be connected. In a joint prosthesis of this kind, the pressure piece includes a pressure disc with a passage opening for the collar extension.

Abstract: In a joint prosthesis the head cap is connected via a collar piece to the shaft piece which may be anchored in the bone. The collar piece is coupled to the shaft piece by a joint head in a ball-jointed manner. The articulation surfaces between the joint cavity in the shaft piece and the articulation head on the collar piece are embodied such that on pressing the articulation head to the base of the joint cavity, edges or projections on the one articulation surface digs into the other articulation surface lying on a virtual spherical surface. It is thus possible to achieve a ball-joint like articulation, whereby the spherical surfaces may have a relatively large production tolerance without the above affecting the clamping connection between the articulation surfaces.

Abstract: A rotation-symmetrical articulation chamber is formed in the shaft head of an endoprosthesis. An axial articulation member is disposed in this chamber. The articulation member axis and the axis of rotation are perpendicular relative to each other. A joint neck can be pivoted about the axis of rotation and the articulation member axis at any selected angle of inclination or rotation. Clamping surfaces that are disposed at an angle to the axis of rotation are rotation-symmetrical or planar and interact with articulation surfaces of the articulation member that can also be rotation-symmetrical.

Abstract: A joint base for a hip joint endoprosthesis includes an elongate base element and a base insert. The base element has a longitudinal axis and an outline which, in a front view, is of asymmetrical design at least relative to the longitudinal axis. The base insert has at a front side a semi-spherical hollow for accommodating a joint ball.

Abstract: An endoprosthetic knee joint has a femur portion, a tibia portion, and a coupling portion. The femur portion has a femur shaft having convexly curved condyle shells at a lower end, the shells having primary slide surfaces and two spaced apart side walls forming an intercondylar space. The tibia portion has a tibia shaft with a tibia plateau at an upper end, upon which are formed secondary slide surfaces. The tibia plateau has an axial recess. The coupling portion has a coupling pin rotatably housed in the recess, and a joint head at the upper end of the pin projects into the intercondylar space. The joint head has a bore extending transversely to the femur axis and is pivotally mounted by a coupling bolt which extends through the bore and is supported on the side walls of the condyle shells. A slide bush may be provided about the medial portion of the coupling bolt to enhance flexion/extension capability and varus/valgus movement.

Abstract: An endoprosthetic knee joint has a femur portion, a tibia portion, and a coupling portion. The femur portion has a femur shaft having convexly curved condyle shells at a lower end, the shells having primary slide surfaces and two spaced apart side walls forming an intercondylar space. The tibia portion has a tibia shaft with a tibia plateau at an upper end, upon which are formed secondary slide surfaces. The tibia plateau has an axial recess with a cross-section which expands toward the plateau from the depth of the recess on one side to a slot in the plateau. The coupling portion has a coupling pin rotatably housed in the recess, and a joint head at the upper end of the pin projects into the intercondylar space. During coupling of the parts of the prosthesis, the knee need not be stretched by the length of the coupling pin, but rather the pin can be introduced into the tibia portion by simple pivoting.

Abstract: The artificial joint part consists of a distal spherical bearing member (1), which can be attached by attachment means (16) to the capitate bone (14) or/and hamate bone (15), and also of a platform (18), which is attached to the radius (6) and at right angles to the longitudinal axis (7) of the radius (6) towards the ulna (8) comprises a guide surface (5). An intermediate member (2) is supported at the proximal end with a sliding surface (4) on the guide surface (5) and is displaceable in the direction of the ulna (8), whereas at the distal end it forms a spherical bearing (3) for the bearing member (1).

Abstract: A femur head prosthesis consists of a shaft having several plate springs fixed unilaterally, which are enclosed by a thin-walled and deformable shell body. The shell body is connected to the shaft edge and seals the enclosed volume so as to be impermeable to air. The plate springs are laminated springs, which are separated by slits. The depth of the slits towards the proximal end leaves a narrow unslit yoke part. When an intermittent load occurs, a slight bending of the yoke part results and, within the yoke part, a slight displacement of the plate springs with respect to one another to result in a damping and a non-linear increase in the compressive force.

Abstract: The femur part is made for clamping to the end of a femur bone in the manner of a "clamp strap". The femur part includes a backwall having a convex outer surface facing a patella shield which is likewise provided with a facing convex surface. The vertex lines of the respective surfaces define a wedge angle which permits the femur part to be clamped to the femur bone. In addition, the vertex lines of the two surfaces are located in a common connecting plane which is perpendicular to the respective tangential planes passing through the vertex lines. The wedge angle may extend up to 30.degree..

Abstract: The tibial implant is made with two truncoconical faces which extend from a common plane for different distances. The differential extent permits implantation in a natural tibia having sockets which have different degrees of wear, thus avoiding unnecessary loss of healthy bone during a resection procedure. The truncoconical faces are provided on metal bowls which can be welded together along a common plane and which together form a support to receive a plastic member providing the joint sliding surfaces and providing a pair of expansion elements for expanding barbed hollow bodies extending from the metal bowls.