Abstract: The prosthesis includes a main element wherein one part forms an articulation side, an element called the “radial” element and an intermediate sliding element. The articulation side that delimits the part of the main element is convex and presents a round form. The intermediate element forms a concave articulation side appropriate for cooperating with the convex articulation side that forms the main element, this concave articulation side presenting, in sectional view in the sagittal plane, that is in the plane in which the flexion and extension movement of the wrist takes place, a rounded circle form very slightly larger than that of the convex articulation side, and presenting, in sectional view in the frontal plane, that is in the plane in which the abduction and adduction of the hand takes place, a rounded circle form markedly larger than that of the convex articulation side.