A prosthesis for reconstruction of a distal radioulnar joint after resection of a part of the ulna close to a distal end portion thereof, wherein the prosthesis comprises a first prosthesis member, one or more fixation means and a second prosthesis member, wherein the first prosthesis member is configured for fixation to the distal end portion of the ulna, wherein the fixation means is/are configured to extend into the radius via said distal end portion of the ulna for immovably locking said distal end portion of the ulna to the radius, wherein the second prosthesis member is configured for fixation to the ulna proximally of a space which is defined between the distal end portion of the ulna and the ulna proximally of said space by the resection of the part of the ulna close to said distal end portion of the ulna, wherein the second prosthesis member is configured to extend into said space for being joined with said first prosthesis member in a manner which allows said first and second prosthesis members to at least pivot and rotate relative to each other, wherein the first prosthesis member comprises a socket portion which is configured with a socket and a mounting portion which is configured for fixation of said socket portion in a cavity in the surface (U1c) of the distal end portion of the ulna facing the space which is defined between the distal end portion of the ulna and the ulna proximally of said space, wherein the second prosthesis member comprises a mounting portion which is configured for fixation in the marrow cavity of the ulna proximally of said space between the distal end portion of the ulna and the ulna proximally of said space, and a head portion which is configured to extend into said space for joining said second prosthesis member with said first prosthesis member, said head portion thereby further being configured with a ball element fitting into the socket of said socket portion such that said first and second prosthesis members can at least pivot and rotate relative to each other. wherein the prosthesis comprises a first prosthesis member, one or more fixation means and a second prosthesis member, wherein the first prosthesis member is configured for fixation to the distal end portion of the ulna, wherein the fixation means is/are configured to extend into the radius via said distal end portion of the ulna for immovably locking said distal end portion of the ulna to the radius, wherein the second prosthesis member is configured for fixation to the ulna proximally of a space which is defined between the distal end portion of the ulna and the ulna proximally of said space by the resection of the part of the ulna close to said distal end portion of the ulna, wherein the second prosthesis member is configured to extend into said space for being joined with said first prosthesis member in a manner which allows said first and second prosthesis members to at least pivot and rotate relative to each other, wherein the first prosthesis member comprises a socket portion which is configured with a socket and a mounting portion which is configured for fixation of said socket portion in a cavity in the surface (U1c) of the distal end portion of the ulna facing the space which is defined between the distal end portion of the ulna and the ulna proximally of said space, wherein the second prosthesis member comprises a mounting portion which is configured for fixation in the marrow cavity of the ulna proximally of said space between the distal end portion of the ulna and the ulna proximally of said space, and a head portion which is configured to extend into said space for joining said second prosthesis member with said first prosthesis member, said head portion thereby further being configured with a ball element fitting into the socket of said socket portion such that said first and second prosthesis members can at least pivot and rotate relative to each other.