Shoulder prosthesis components and assemblies

A stemless humeral anchor, comprising:

• a distal portion extending proximally from a distal end of the stemless humeral anchor, the distal portion configured to occupy a portion of a metaphysis of a humerus when implanted;
• a proximal portion extending distally from a proximal end of the stemless humeral anchor;
• a recess extending distally from the proximal end of the stemless humeral anchor and into the proximal portion;
• and
• an inner periphery disposed about the recess adjacent to the proximal end of the stemless humeral anchor, the inner periphery comprising:
• a concave locking feature disposed in the inner periphery;
• and
• a convex locking feature disposed in the inner periphery, the concave locking feature spaced apart from the convex locking feature.

A humeral anchor, comprising:

• a distal portion extending proximally from a distal end of the humeral anchor, the distal portion configured to occupy a portion of a metaphysis of a humerus when implanted;
• a proximal portion extending distally from a proximal end of the humeral anchor and having an outer surface that is enlarged to occupy at least a majority of the volume of a metaphysis of a humerus into which the humeral anchor is to be disposed, the proximal portion having a lateral side configured to be disposed adjacent to a cortical wall of a lateral portion of a humeral metaphysis and a medial side configured to be spaced apart from a cortical wall of a medial side of the humeral metaphysis;
• and
• a bone compression surface disposed at the proximal end of the humeral anchor, the bone compression surface being disposed about the medial side of the proximal portion and being configured to extend from the medial side of the proximal portion to the cortical wall of the medial side of the humeral metaphysis when implanted in a humerus,
• wherein the bone compression surface comprises a flange that extends outward from the proximal end of the proximal portion of the humeral anchor.