The morphology of the articular surfaces of biological knee joints provides essential guidance for the construction of functional knee endoprostheses.

Purpose: In comparative examinations of kinematics of the knees of humans and pigs in flexional/extensional motion under compressive loads, the significant differential geometric essentials of articular guidance are elaborated to criticise the shaping of the articular surfaces of conventional knee-endoprostheses and to suggest constructional outlines that allow the endoprosthesis to adopt natural knee kinematics. Implantation is discussed with regard to the remaining ligamentous apparatus.

Methods: Twelve fresh pig knee joints and 19 preserved human knee joints were moved into several flexional/extensional positions.