Systems and methods of thumb caropmetacarpal joints implants

An apparatus, comprising:

• a metacarpal implant, comprising:
• a stem having a first end and a second end;
• a radial lip extending from the second end;
• and
• an opening extending from the radial lip to the first end, wherein the stem comprises an inner stem surface facing the opening and the radial lip comprises an outer surface and an inner lip surface facing the opening, the inner stem surface and the inner lip surface connected by a seat extending from the inner stem surface;
• and
• a spacer, comprising:
• a spacer head portion having a top surface and a bottom surface, the bottom surface in contact with the surface;
• and
• an opening insert to be inserted in the opening and extending from the bottom surface.

A metacarpal implant, comprising:

• a stem configured to be inserted into a first cavity of a metacarpal bone and having a first end and a second end, the stem centered on a first axis;
• a radial lip extending radially outwards from the second end, the radial lip centered on a second axis parallel to and offset from the first axis;
• and
• an opening extending from the radial lip to the first end and including a first portion, a second portion, and a third portion, the first portion located within the radial lip and centered on the second axis, the second portion and the third portion located within the stem and centered on the first axis.