Assembly consisting of head and movable neck for preparing the implantation of an artificial hip

Assembly (1) consisting of head (2) and movable neck (3) for preparing the implantation of an artificial hip, the said head (2) and the said movable neck (3) having, respectively, a frustoconical hole (2t) and a frustoconical portion (3t) able to be inserted in a complementary manner therein, characterized in that the flat end (3e) of the said frustoconical portion (3t) has, coaxially formed or mounted thereon, a o cylindrical protrusion (4) having a diameter (D) smaller than the diameter of the frustoconical portion (3t) opposite its said flat end (3e) and in that the said frustoconical hole (2t) has a coaxial, blind, cylindrical extension (5) from the side walls of which an annular protrusion (6) having an internal diameter (d) which produces a slight interference with the diameter (D) of the said cylindrical protrusion (4) of the frustoconical portion (3t) projects, and the height (H) of the said cylindrical extension (5) of the frustoconical hole (2t) is greater than or equal to the height (h) of the abovementioned cylindrical protrusion (4) so that, when the latter (4) is inserted over its entire height inside the said cylindrical extension (5), the said flat end (3e) of the frustoconical portion (3t) bears against a concentric shoulder (7) formed on the head (2) around the said cylindrical extension (5) before forced engagement occurs between the surfaces of the frustoconical portion (3t) of the neck (3) and the frustoconical hole (2t) in the head (2).