Abstract: An endoprosthesis for replacing at least part of a tibia, includes an elongate shaft extending longitudinally in the direction of a lower leg and having an upper end facing a knee joint and a lower end facing a natural talus. An endoprosthetic knee joint having a tibial plateau is secured to the upper end of the shaft. The talus supports a coupling portion which is connected to the lower end of the shaft.

Abstract: A saddle-type prosthesis for replacement of a hip joint; includes a shank assembly for engagement in a femur, a saddle-shaped head having a seat to form a bearing area for engagement by a portion of a pelvic bone, and a mounting for so coupling the saddle-shaped head to the shank assembly as to permit a pivoting of the saddle-shaped head relative to the shank assembly about at least two predetermined axes for rotation with at least two degrees of freedom wherein one of the predetermined axes is positioned above the bearing area of the saddle-shaped head.

Abstract: A knee joint prosthesis with a tibial component, a femoral component and a hinge which connects the two components and defines a pivot axis at a fixed distance from both components. The planes of the axes of shanks of the two components are located at selected distances from each other and from the pivot axis, and the pivot axis is placed nearer to the rear portions than to the front portions of the two components. This reduces the need for resection of affected bones and enhances the transfer of forces as well as the stability of the prosthesis.

Abstract: A hip prosthesis wherein a saddle-shaped head has a seat flanked by two horns and engageable with the surface bounding a recess in the lower part of a damaged pelvic bone. The head is rotatably or rigidly secured to a substantially S-shaped adapter which, in turn, is rotatably or non-rotatably secured to the adjacent end of a shank that is implantable in the cavity of a femur. One or more distancing rings can be inserted between the adapter and the head.

Abstract: A knee joint prosthesis wherein a first component which is partially embedded in the femur carries a pivotably mounted tubular guide for a pin-shaped second guide mounted on a second component which is partially embedded in the tibia. The second guide is rotatable and reciprocable in the tubular guide, and the extent of the reciprocatory movement is limited by two abutments one of which is mounted on the first component and the other of which is mounted on the second component.

Abstract: A prosthesis which is particularly well-suited for use in the region of the hip joint has a shaft which carries a bearing at one end. The bearing has a rim at its junction with the shaft. The end of the bearing opposite the rim has a saddle-shaped portion including a pair of protrusions which flank a depression. The depression has a pair of bearing surfaces separated by a protuberance which is formed in the depression and extends from one of the protrusions to the other. The prosthesis is installed at a hip joint by inserting the shaft into the end of the femur nearest the pelvis. The shaft is pushed into the femur until the rim on the bearing contacts the end of the femur. One of the protrusions is passed through an opening in the wall of the pelvis so that the wall is received in the depression of the bearing. The wall is contoured so as to conform to the shape of the depression and the protuberance therein and rests on the surface of the protuberance as well as the bearing surfaces of the depression.

Abstract: A prosthesis for the knee joint has a tibial component and a femoral component. No mechanical connection exists between these components. The tibial component includes a shaft which carries a platform and is received in the cavity of the tibia so as to position the tibial component. The platform supports a bearing element which engages the femoral component and, in addition, a projection is mounted on the platform and extends towards the femoral component. The femoral component includes a shaft which carries a hinge and is received in the cavity of the femur to position the femoral component. The hinge, which defines a pivot axis for bending of the knee, comprises a hinge pin having a recess which faces the tibial component. The projection is slidably received in the recess and defines a rotational axis about which limited rotation of the tibial component relative to the femoral component may take place. In addition, the projection maintains the hinge pin in requisite position.