Artificial head assembly for an articulated joint between two bones

US4012795A · kind A · utility

Assignee

• Feldmuhle Anlagen und Produktionsgesellschaft mit beschrankter Haftung

Inventors

• Erhard Dorre · Plochingen, DE
• Manfred Semlitsch · Winterthur, CH
• Otto Frey · Winterthur, CH

Key dates

• Filing date: Oct 29, 1975
• Grant date: Mar 22, 1977
• Expiry date: Oct 29, 1995

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16C2316/10
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

An artificial head assembly for a human femur consists of the head portion roper and a metal pin. The head portion is a sintered ceramic ball having a polished contact face of convex, spherical curvature and a blind bore tapering conically inward toward the contact face. The pin is shaped for insertion of one end into the hollow stump of the femur, the other end tapering conically at the same apex angle as the bore in the ball. A knurling of the conical face of the pin reduces the compressive strength of the pin surface to less than the tensile strength of the ball so that the assembled head and pin can be sterilized without cracking the ceramic head portion because of differences in coefficients of thermal expansion between the metal and the ceramic material.