Abstract: According to the state of the art, the replacement of a basal finger joint is effected by, for example, interposition of soft part tissue or a distance piece, which does not, however, constitute a replacement joint. In joint prostheses with a metal-metal sliding combination, but in particular with a metal/polyethylene sliding combination, wear of the material can lead to osteolyses at the bone ends. Owing to the fact that the metal or plastic joint prostheses known from the state of the art are as a rule multipart, loosening of the individual components can occur, which shorten the service life of the implant.

Abstract: According to the state of the art, the replacement of a basal finger joint is effected by, for example, interposition of soft part tissue or a distance piece, which does not, however, constitute a replacement joint. In joint prostheses with a metal-metal sliding combination, but in particular with a metal/polyethylene sliding combination, wear of the material can lead to osteolyses at the bone ends. Owing to the tact that the metal or plastic joint prostheses known from the state of the art are as a rule multipart, loosening of the individual components can occur, which shortens the service life of the implant.

Abstract: The articulated prosthesis comprises two cooperating prosthesis portions each portion having an anchoring stem to fix the prosthesis portion in a bone. The first prosthesis portion is provided with a essentially ball-shaped head member which comprises two diametrically opposite flattened portions. The second prosthesis portion is provided with a shell member having essentially the shape of a spherical sector and having a height which is greater than the radius of the head member. It is provided with a window allowing the assembling of the first and second prosthesis portions in an assembling position. To assemble the two portions to an articulated prosthesis, the two portions are aligned to each other in the assembling position, the head member is inserted into the shell member and the two portions are rotated with respect to each other into an operating position. In that operating position, the articulated prosthesis may be subjected to a pull strain without the danger of luxation.

Abstract: The artificial joint part consists of a distal spherical bearing member (1), which can be attached by attachment means (16) to the capitate bone (14) or/and hamate bone (15), and also of a platform (18), which is attached to the radius (6) and at right angles to the longitudinal axis (7) of the radius (6) towards the ulna (8) comprises a guide surface (5). An intermediate member (2) is supported at the proximal end with a sliding surface (4) on the guide surface (5) and is displaceable in the direction of the ulna (8), whereas at the distal end it forms a spherical bearing (3) for the bearing member (1).