David R Greene

US Patent:

43522122, Oct 5, 1982

Filed:

Jun 20, 1980

Appl. No.:

6/161503

Inventors:

David J. Greene - Boston MA
Peter S. Walker - Ridgewood NJ

Assignee:

Howmedica, Inc. - New York NY

International Classification:

A61F 103

US Classification:

3 191

Abstract:

A novel joint prosthesis, particularly suitable as a metacarpophalangeal joint prosthesis, is disclosed comprising first and second intramedullary plugs adapted to be secured to the walls of the intramedullary canals of the two bones forming the joint, and first and second components each comprising a bearing portion and a stem slidably received in a longitudinal bore provided in each of said intramedullary plugs. Transmission of stresses to the bone-prosthesis fixation interfaces is substantially reduced as a result of the freedom of motion of the stems within these longitudinal bores. In a preferred embodiment, axial rotation of one, but only one, of said stems with respect to the intramedullary plug receiving it is prevented. Use of preferred configurations for the bearing portions of the two components provides an accurate reproduction of the movement and degrees of freedom of the natural metacarpophalangeal joint.