Abstract: An artificial knee joint comprising: a femoral component comprising a femoral condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have convex exterior surfaces, and a tibial component comprising a tibial condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have concave interior surfaces so as to slidably receive the medial and lateral condylar sections of the fermoral condylar portion therein; and a space between the respective medial and lateral condylar sections of the femoral condylar portion and of the tibial condylar portion being formed so as to be gradually narrower toward the rear side of the knee joint, thus forming a “rear-in” configuration.

Abstract: An artificial socket comprising a composite body of a calcium phosphate compound and an in vivo-absorptive polymeric material. The artificial socket is embedded and secured in the pelvis side of the artificial hip joint. The socket has a configuration of a semi-spherical shell body, and the thickness thereof is thinner than that of a conventional artificial socket and the inner diameter thereof is substantially the same as that of a real socket in a human bone. An artificial hip joint using the artificial socket and a fixing screw suitable for the fixation of the socket in the pelvis are also disclosed.

Abstract: A magnetostrictive brake is provided with an electrically-driven actuator for moving friction materials back and forth toward a rotary member by utilizing a magnetostrictive element which extends and contracts by means of magnetostriction, a fluid-type displacement enlarging mechanism which is provided between the magnetostrictive element and the friction materials and used for enlarging the displacement of the magnetostrictive element and transmitting the enlarged displacement to the friction materials, and bias magnetic field applying means for applying a bias magnetic field to the magnetostrictive element.