On October 7, 1975, Ysidore M. Martinez was granted for a knee implant prosthesis (This Day in Patent History)

















Problems solved by this invention
Previous knee implant prosthesis devices did not provide for a natural knee action or utilize unduly complex structures to obtain the complex motion that is accomplished by a natural knee.

Solutions provided by this invention
The invention provides a pivot structure having a relatively large pivot center spacing between dual pivot bearings but which has a small overall size, so that a full knee flexion may be obtained without entrapment of body tissues. The movements of the natural knee referred to as rotation and adduction-abduction are accommodated in the interconnection between the attachment means and the pivot roller element.

Patent Information
Patent Title: Knee implant prosthesis
Publication number: US3909854 A
Publication type: Grant
Publication date: 7 Oct 1975
Filing date: 18 Nov 1974
Priority date: 3 May 1973
Inventors: Martinez Ysidore M

Abstract: A knee prosthesis for replacing the functions of the natural knee including the ability of the natural knee to rotate, abduct-adduct and flex. The device incorporates spaced pivot bearings mounted in a pivot body. The pivoting structure is connected to the natural bone structure by a connector screw received in the bone, and a connector shield received in a cavity surgically prepared in the bone. Resilient plastic material provides a resistance restoring force for the abduction-adduction and rotation modes.