Artificial knee joint, and bridge member, insert member and base plate used therein

An unicompartmental artificial knee joint comprising:

• an insert member sized and configured to be embedded in only a part of a joint surface of a medial condyle or lateral condyle of a tibia;
• a pair of elongated bridge members sized and configured to be disposed underneath the insert member, each elongated bridge member having a length that allows opposite ends of the bridge member to be anchored to a cortical bone of the tibia, and supporting the insert member from below;
• and
• a cylindrical base plate disposed between the insert member and the bridge members, and supporting an outer edge of the insert member,
• wherein a longitudinal axis of each bridge member is disposed parallel to a bottom surface of the insert member,
• wherein the insert member has a circular shape, an elliptical shape, or a semicircular shape in plain view,
• wherein a top surface of the insert member is formed into a recessed curved surface, a protruding curved surface, or a flat surface, the top surface sized and configured to articulate with a femur or femoral component,
• wherein the insert member has a peripheral surface adjusted in height and shape so that the peripheral surface, when the insert member is embedded, is completely surrounded and smoothly connected to surrounding original joint surface.