Joint endoprosthesis

US4944762A · kind A · utility

Assignee

• interplanta Arzt-und Krankenhausbedarf GmbH · DE

Inventors

• Helmut D. Link · Hamburg, DE
• Arnold Keller · Kayhude, DE

Key dates

• Filing date: Sep 11, 1986
• Grant date: Jul 31, 1990
• Expiry date: Sep 11, 2006

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61F2002/3631
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

The invention relates to a femoral hip-joint endoprosthesis having a shaft to be inserted into the medullary cavity (4) of the femur (1) and a support plate (7), which terminates the shaft proximally and the under surface (12) of which is provided for support on the resection surface (16) of the bone. The overall axis (6) of the resection surface is inclined. The prerequisites for the transfer of forces from the prosthesis to the bone are improved when the under surface (12) and the resection surface (16), which is prepared to be of the same shape, are formed so that the medial part of the under surface includes an angle with the axis of the femur which is, on average, larger than its lateral part. A cylindrical shape of the two surfaces witha cylindrical axis running from anterior to posterior, or a spherical shape, are particularly advantageous. Furthermore, it is advantageous to form the under surface as a surface of revolution about a rotation axis running transverse to the under surface. This permits very exact preparation of the resection surface with a cutter which is held in a predetermined position by a holding shaft which coincides with the shaft of the prosthesis and whi…