A carpometacarpal prosthesis system generally includes a trapezial implant for replacing an excised trapezium within a human hand and a component stem implant for replacing a partially excised first metacarpal. The component stem implant is adapted to be press fit within the medullary cavity of the partially excised first metacarpal bone of the human hand the component stem when so implanted is adapted to effect universal movement of the first metacarpal bone relative to the trapezial implant thereby providing a restructured thumb metacarpal joint that restores substantially normal thumb function in terms of strength and flexibility.