Pre-operatively planned humeral implant and planning method

A pre-operative planning method for designing a humeral prosthetic implant having a cup including a stem projecting outwardly from a surface of the cup at at least one of an offset and an angle, the method comprising:

• analyzing one or more of humerus stem size, length, head diameter, head height, head offset, rotation (axial), humeral diaphysis and/or metaphysis offset of a patient to be treated,
• wherein the cup includes:
• a first end and a second end, the first end defining a first interior recess that extends inwardly toward the second end;
• an exterior backside extending from the second end toward the first end;
• wherein a second additional recess is defined at the first end of the cup, the second additional recess sized and configured to receive a snap ring when the snap ring is inserted into a groove in an articular liner such that the interior recess is configured to receive and securely hold the articular liner, and
• wherein the exterior backside is configured to be received within the head of the humerus, the exterior backside including at least one fin, rib, or projection extending away from the exterior backside and which is configured or sized and shaped to provide rotational control under a torsional load;
• and
• storing a design for the humeral prosthetic implant in a non-transitory computer readable media.