The invention relates to a prosthesis for movably coupling os metacarpale I of a hand to a second metacarpal bone of the hand, which prosthesis includes a first and a second element. The first element includes a first attachment member, which first attachment member is configured for attachment to os metacarpale I, and the second element comprises a second attachment member, which second attachment member is configured for attachment to the second metacarpal bone, which first and second element are movable relative to each other. The second metacarpal bone is os metacarpale II of the hand and the second attachment member is configured to be arranged from the radial side of os metacarpale II. The invention also relates to a combination of a prosthesis according to the invention and at least one fastening means.
