Other

Nakashima Propeller Co., Ltd.

Nakashima Medical Co., Ltd.

Koichi Kuramoto

Keitaro Yamamoto

Toru Suguro

Satoshi Hayakawa

Kanji Tsuru

Akiyoshi Osaka

Ryutaku Kaneyama

Keitarou Yamamoto

Daisuke Maruyama

Atsushi Sugino

Kenji Doi

A bone resection jig that can make ligament tension equal at extension and flexion positions without any actual measurements when resecting femur and tibia during artificial knee joint replacement surgery. The bone resection jig used in artificial knee joint replacement surgery includes a spacer block () comprised of a grip (), a hollow box () that is provided on an other end side of the grip and has a vertical hole () therein, and a reference spacer part () that extends out from the hollow box () and is adapted be inserted into the resection region between femur and tibia; a reference pin guide () which, when the femur and tibia are in the flexion position, is inserted into the vertical hole () of the hollow box, extends on the reference spacer part () to the other end side of the grip so as to come into contact with a resection plane (F) of the tip of the distal end of the femur, and is formed with guide holes () for guiding reference pins () to be installed from a front side into the resection plane (F) of the tip of the distal end of the femur; and an aiming member () which is, after the spacer block () has been removed from a space between the femur and tibia leaving the reference pins (), brought onto the reference pins () by being guided thereby, the aiming member being provided with an indicator () that indicates a resection plane (F) at a back of the distal end of the femur when the aiming member () comes into contact with the resection plane (F) of the tip of the distal end of the femur.

Bone resection jig used in artificial knee joint replacement surgery

By forming a bone-compatible implant wherein a groove or hole has been formed in the surface of a base material made of titanium metal or a titanium alloy at its joint with a bone tissue and the groove or hole has on the inner surface thereof an oxide film formed by heating in an oxygen-containing atmosphere, apatite is allowed to deposit on the inner surface of the groove or hole easily. Thus, an implant is provided which can be attached to a bone within a relatively short period of time even without resorting to bone cement.

Bone-compatible implant and method of producing the same

An artificial knee joint including a femoral component and a tibial component which are in relation of making relative rotation, in which the tibial component has a post that has an outwardly curving posterior surface and is disposed approximately in the longitudinal center between the articular surfaces so that the post is inside an intercondylar groove that is between the medial and lateral condyles and extends from the posterior end to the anterior end of the femoral component; and the femoral component has a cam that is disposed at the posterior portion of the intercondylar groove and comes into contact with the posterior surface of the post when the above-described rotation proceeds; and the post and the cam are shaped so that the femoral component is turned outwardly when the cam comes into contact with the post as a result of the rotation and as the rotation proceeds.

Artificial knee joint

An artificial knee joint including a femoral component to be attached to a femur and a tibial component to be attached to a tibia, wherein in the femur component a medial condyle thereof is thicker than a lateral condyle thereof; in the tibial component, a medial articular surface thereof, which supports the medial condyle of the femur component, is thinner or deeper than a lateral articular surface thereof, which supports the lateral condyle of the femur component; and a joint line joining the lowest points of contact surfaces between the medial and lateral condyles of the femur component and the medial and lateral articular surfaces of the tibial component in a longitudinal cross section in a medial-lateral direction is inclined inward at virtually the same angle over the entire region of an angle of flexion-extension.

Growing community of inventors

Okayama, Japan

Koichi Kuramoto