Abstract: The implant comprises a stem (10) terminating in a head (20). The stem is adapted to be inserted in the metacarpus of the thumb and the head to be disposed in a space obtained particularly by removing at least a portion of the trapezium. The surface of the head is constituted by a base (201) connected to the stem and adapted to rest on the proximal end of the metacarpus, a distal surface portion (202) opposite the base and serving as a contact surface with the bone located facing the proximal end of the metacarpus, and a connecting portion (203) connecting the base and the distal surface portion of the head. The distal surface portion (202) of the head is inclined relative to a longitudinal axis (104) of the stem by a predetermined angle (?), such that, when the stem (10) is mounted straight in the metacarpus, the distal surface portion (202) of the head can be located in varus.

Abstract: The implant includes a stem terminating in a head. The stem is adapted to be inserted in the metacarpus of the thumb and the head to be disposed in a space obtained particularly by removing at least a portion of the trapezium. The surface of the head is constituted by a base connected to the stem and adapted to rest on the proximal end of the metacarpus, a distal surface portion opposite the base and serving as a contact surface with the bone located facing the proximal end of the metacarpus, and a connecting portion connecting the base and the distal surface portion of the head. The distal surface portion of the head is inclined relative to a longitudinal axis of the stem by a predetermined angle, such that, when the stem is mounted straight in the metacarpus, the distal surface portion of the head can be located in varus.

Abstract: A conical coupling of a male member (10) and a female member (11), the male member (10) comprising a cone (12) ensleeved in a truncated conical portion (15) of a corresponding recess (14) formed in the female member (11), is characterized in that the female member (11) is made of a material having a Young's modulus at most equal to about 35 GPa and at most equal to that of the material from which the male member (10) is made, and in that a surface (13) of the male member perpendicular to the axis (A1) of the coupling is in contact with a surface (17) of the female member also perpendicular to the coupling axis such that the male and female members (10, 11) are in axial abutment against each other. The female member (11) is for example of pyrocarbon and the male member (10) of metal, ceramic or pyrocarbon.

Abstract: The implant includes a stem terminating in a head. The stem is adapted to be inserted in the metacarpus of the thumb and the head to be disposed in a space obtained particularly by removing at least a portion of the trapezium. The surface of the head is constituted by a base connected to the stem and adapted to rest on the proximal end of the metacarpus, a distal surface portion opposite the base and serving as a contact surface with the bone located facing the proximal end of the metacarpus, and a connecting portion connecting the base and the distal surface portion of the head. The distal surface portion of the head is inclined relative to a longitudinal axis of the stem by a predetermined angle, such that, when the stem is mounted straight in the metacarpus, the distal surface portion of the head can be located in varus.

Abstract: A conical coupling of a male member (10) and a female member (11), the male member (10) comprising a cone (12) fitted in a truncated conical portion (15) of a corresponding recess (14) formed in the female member (11), is characterized in that the female member (11) is made of a material having a Young's modulus at most equal to about 35 GPa and at most equal to that of the material from which the male member (10) is made, and in that a surface (13) of the male member perpendicular to the axis (A1) of the coupling is in contact with a surface (17) of the female member also perpendicular to the axis of the coupling such that the male and female members (10, 11) are in axial abutment against each other. The female member (11) is for example of pyrocarbon and the male member (10) of metal, ceramic or pyrocarbon.