Humeral joint replacement component

A method of replacing a portion of a joint of a patient, comprising:

• making an incision in the patient and exposing a native articulating surface of the joint;
• cutting bone of the joint to remove at least a portion of the native articulating surface, and to form a spherical shape;
• positioning a prosthetic head, at any of a plurality of angles, upon the spherical shape of the cut bone, the prosthetic head comprising a replacement articulating surface having a shape of a semi-ellipsoid, and a bottom surface, the replacement articulating surface having a central point and a central semi-spherical portion being centered upon the central point and being semi-spherical with a predetermined radius of curvature extending across about 30% of the replacement articulation surface, at least a portion of the replacement articulation surface other than the central semi-spherical portion being semi-elliptical;
• wherein the replacement articulation surface includes a superior to inferior maximum separation distance which intersects the central point and an anterior to posterior maximum separation distance which is substantially perpendicular to the superior to inferior maximum separation distance and intersects the central point;
• and
• wherein a superior to inferior surface curvature length of the replacement articulation surface along the superior to inferior maximum separation distance is greater than an anterior to posterior surface curvature length along the anterior to posterior maximum separation distance, the prosthetic head further having a spherical chamber formed in the bottom surface, the spherical chamber sized and dimensioned to conform to the size and dimension of the spherical shape of the cut bone;
• and
• inserting the cut bone of the joint into the spherical chamber;
• wherein the prosthetic head therapeutically replaces the removed portion of the native articulating surface.