Humeral shoulder prosthesis

A modular humeral shoulder prosthesis for implant in a predetermined position in the natural humerus to replace the natural humeral head of a shoulder joint with a prosthetic implant, the humeral shoulder prosthesis comprising:

• a humeral head component including a humeral head member having a spherical bearing surface with a predetermined radius extending from an origin to the bearing surface, an undersurface extending in a first direction and including a central location, an elongate post integral with and projecting in a given direction from the humeral head member, the given direction making a first acute angle with the first direction, the post extending along an axis which intersects the undersurface at a further location spaced laterally away from the central location, the post being integral with the humeral head member at said further location, and a post portion on the post;
• and
• a humeral stem component including a platform having an upper surface, a stem integral with and depending from the platform, the stem extending along a longitudinal axis for alignment generally longitudinally along the natural humerus, the upper surface extending in a second direction making a second acute angle with the longitudinal axis, and an elongate recess in the stem, the recess extending along the stem and including at least a recess portion complementary to the post portion for reception of the post portion within the recess portion in an integrated coupled assembly wherein the humeral head component is affixed to the humeral stem component with the undersurface of the humeral head member confronting the upper surface of the platform when the bearing surface is in the predetermined position to replace the natural humeral head.