Harrington Arthritis Research Center

Thomas P Murray

Roger H Johnson

James B Koeneman

Thomas M Hansen

Allan M Weinstein

Joseph A Longo

Roy Drake Bloebaum

Frank P Magee

A femoral-side hip-joint prosthetic device for use in hip-joint replacement. The device includes an elongate stem whose surface defines maximally spaced infero-medial and supero-lateral surface curves, and which is characterized by a surface rotation which carries the supero-lateral surface curve about 15.degree.-30.degree. forward with respect to the infero-medial surface curve, on progressing upward along the upper surface portion of the stem, with the device in operative position. The rotation of the stem surface produces a close approximation to the cavity formed in the proximal femur by removal of the cancellous bone in the natural cavity formed by a wall of densified cancellous bone. A 3.degree.-15.degree. proximal anteversion of the neck is adapted to place a hip-joint ball carried on the stem at a position closely approximating that of the head in the natural femur. In the method of the invention, the cavity which receives the prosthesis stem is formed by a rasp/broach-type tool whose surface conforms closely to that of the stem.

Femoral-joint prosthetic device

An improved tibial component is provided for a knee prosthesis, wherein the tibial component includes a pair of tibial tray members adapted to accommodate independent longitudinal shifting during patient function while retaining a secure and stable fixation with respect to patient bone. The two tibial tray members comprise medial and lateral members for supporting the medial and laternal condyles of a knee joint. These tray members are interconnected by a slide key arrangement which restrains the tibial tray members against relative movement in the anterior-posterior and medial-lateral directions, while permitting relative shifting in a longitudinal direction corresponding generally with a central axis of the patient's tibia. In the preferred form, the two tibial tray members cooperatively define a common anchoring post and include one or more antirotation fins for mechanically locking with patient bone. In addition, in the preferred form, the two tray members include appropriate bone ingrowth surfaces for secure noncemented attachment to patient bone.

Tibial component for a knee prosthesis

A femoral-side hip-joint prosthetic device for use in hip-joint replacement. The device includes an elongate stem whose surface defines maximally spaced infero-medial and supero-lateral surface curves, and which is characterized by a surface rotation which carries the supero-lateral surface curve about 18.degree.-30.degree. forward with respect to the infero-medial surface curve, on progressing upward along the upper surface portion of the stem, with the device in operative position. The rotation of the stem surface produces a close approximation to the cavity formed in the proximal femur by removal of the cancellous bone in the natural cavity formed by a wall of densified calcellous bone. A 3.degree.-15.degree. proximal anteversion of the neck is adapted to place a hip-joint ball carried on the stem at a position closely approximating that of the head in the natural femur. In the method of the invention, the cavity which receives the prothesis stem is formed by a rasp/broach-type tool whose surface conforms closely to that of the stem.

Growing community of inventors

Scottsdale, AZ, United States of America

Thomas P Murray