The invention relates to an artificial joint element (1) for use in one or more single joints in a system of joints that consists of a combination of several kinematically coupled single joints, (series connection), in particular for use in one or more human finger joints. Said element comprises an essentially concave joint shell (2) and an essentially convex joint head (3). The aim of the invention is to obtain displacement characteristics for the artificial joint element (1), resulting from the additional degrees of freedom that are produced by incongruence, that mimic the natural behavior in an optimal manner. To achieve this, the joint element (1, 6) comprises at least four degrees of freedom and when used in the metacarpophalangeal joint, five degrees of freedom. For this purpose, the concave joint shell (2) comprises a curved contact line running over its surface with a first radius (R) and the concave joint head (3) has a contact line that is also curved running over its surface with a different second radius (r), which is smaller than the radius (R) of the contact line of the joint shell (2).