US Patent 6863690 Humeral shoulder prosthesis

The humeral portion of a shoulder prosthesis includes a diaphyseal component configured for fixation within the humerus, a metaphyseal component, configured for removable implantation within the metaphysis of the humerus, and an engagement mechanism for removably engaging the two components. The metaphyseal component can initially include a convex articulating surface that can be replaced with a concave surface during the shoulder arthroplasty procedure or in a subsequent revision surgery. The metaphyseal component can also include a feature to facilitate removal of the component from the bone once it has been disengaged from the diaphyseal component.