Abstract:
Pairs of partner elements for artificial joint implants have two-dimensional surface contact in which one joint part (1) rotates, rolls, slides or combines these in one movement relative to another joint part (2). A gap (10) is formed between the sliding partner elements for a film consisting of natural synovia fluid. The surface of at least one of the sliding partner elements has regularly positioned recesses (3) which serve as a reservoir for the synovia.
Abstract:
A prophylactic implant is provided for protecting osteoporosis-affected bone segments against fractures, in particular the neck of the femur, the vertebral column and the wrist. According to a proposed solution, the implant comprises a thin-walled hollow reinforcing body (1) having such a large number of passages (2) in its outer wall (3) that the ratio of the total area of the passages (2) to the total surface area is at least 1:2.
Abstract:
A femur endoprosthesis for an artificial hip joint is provided with a stem (1) which can be implanted without cement in the upper region of a femur below the greater trochanter. The proximal end (8) of the stem is connectable with an adapter (2) for accommodating an artificial spherical part of a joint (20). The exterior of the stem is at least partially covered with an open-meshed three-dimensional spatial lattice structure (9). A distal end of the stem is bent caudally with a caudally oriented step (31) in the transition area and constructed as a stem end (30), which is also at least partially covered with an open-meshed three-dimensional spatial lattice structure (9).
Abstract:
This invention relates to knee-joint endoprostheses, and provide an endoprosthetic member embodying condylar replacement surface means to simulate the natural slideway for the knee cap, said slideway defining a space for the cruciate ligaments of the natural joint, and also having a curved boundary to be brought into alignment with the transverse edge of the natural joint which forms the upper boundary of the space for the cruciate ligaments relative to the intercondylar eminence. The prosthesis for the inner tibial plateau is made concave and the prosthesis for the outer tibial plateau is made saddle-shaped to match the natural tibial plateaus, all the prosthetic parts being made from a wear-resistant plastics material such as polyethylene for example.More generally, the invention provide an endoprosthetic condylar surface member comprising a shell of wear-resistant plastics material having a cupped shape connected to a slideway projecting laterally therefrom or alternatively the shell may comprise two cup-shaped parts interconnected by a slideway bridging piece.
Abstract:
A knee joint endoprosthesis has an element for the femur (2) which is substantially U-shaped when seen from a medial to a lateral angle, one horizontal, two diagonal and two vertical support surfaces facing the femur for accommodation on the resected femur bone, which is fitted with two runners (24, 25), and an element for the tibia (1) having two slide tracks (4, 5) on which the runners for the femur element can roll, and optionally slide, and a horizontal support surface (6) facing the tibia for accommodation on the resected tibia. The femur element (20) and tibia element (1) are configured without any shanks. At least both diagonal support surfaces of the femur element (2) and the horizontal support surface (6) of the tibia element (20) are fitted with an open-mesh, three-dimensional spatial network structure (7) which is an integral component of the base structures (8, 8′) of the femur element (20) and the tibia element (1). Two latches (21, 22) angled toward the femur and provided with at least one respective through hole (23) are medially and laterally formed on the femur element (20), whereby a bone screw (26) can be inserted therein; and two latches (11,12) angled toward the tibia and provided with at least one respective through hole (18) are formed on the tibia element, whereby a bone screw (14) can be inserted therein.
Abstract:
A knee joint endoprosthesis is provided having a femoral part (1) that can be linked with a shank part to be anchored in the femur, the femoral part being provided with two runners (2, 3) interlinked ventrally via a bridge. A tibia plateau part (5) interacts with a shank part to be anchored in the tibia and is provided with two slide guides (6) in which the runners (2, 3) of the femoral part (1) can roll off and slide. With increasing bend of the knee joint and upon exceeding a predetermined bending angle, the femoral part is allowed to perform an increasing rotation relative to the tibia plateau part (5).
Abstract:
This invention relates to shanks for knee joint endoprostheses which, on implantation, are inserted in a space prepared in the spongiose and marrow of the receiving bone. The invention consists in matching the external contour of the shank for at least a part of its length to the cross-section of the medullar cavity in a normal human bone receiving the shank.
Abstract:
A knee-joint endoprosthesis comprising an upper and lower shank for attachment to the femur and tibia and provided with two pads which are yoked together across a central ridge. In such an endoprosthesis, the invention provides the improvement which consists in that a saddle-shaped ridge is provided with a fixed guiding cross-shaft which forms a free spigot on either side of said ridge and which lies off and to the rear of the center axis of said lower shank when the joint is in the extended position, in that two curved, hollowed-out bearing faces, and said supporting pads, which conform to said bearing faces in the extended position, diminish in width from front to rear as a result of said ridge becoming wider in the rearwards direction, in that said spigots engage with clearance in guide grooves in said supporting pads which extend approximately parallel to the lower faces of said pads and which open upwards at their rear ends, and in that the extension of the two sections of the joint is restricted by an abutment.
Abstract:
The invention relates to a hydraulically assisted steering system for a motor vehicle. Because there is associated with the hydraulic system an electromechanical valve 12 which, in the open state, hydraulically indirectly or directly connects the working chambers 3 , 4, it is possible to dispense with conventional mechanical pressure limiting valves, secondary suction valves and limit stop valves.
Abstract:
An implant to replace a rear patella part is provided, which comprises a prosthesis part imitating the patella part and a metal attachment part fixed in the prosthesis part, with which the implant can be attached in the natural patella part. In order to produce a gentle and secure attachment for the implant, the attachment part has a convexly curved external contour, which at least in sections has an open-cell and open-pore surface structure.