A device for implanting and assembling in a patient comprising a base piece (1) that is equipped to be anchored in bone tissue (11) with the help of a first liquefiable material and mechanical vibration, and a piece based (2), which is equipped to be connected in situ to the base piece (1) either after or at the same time as the base piece (1) is anchored in the bone tissue, where each of the two pieces (1, 2) The device comprises one of a pair of matching junctions, of which one first (F) comprises a second liquefiable material and a second (S) comprises a non-liquefiable material and a structure that is suitable to form a positive fitting connection with the second liquefiable material, and where the place of attachment of the base piece (1) is located on a proximal or lateral side thereof and the place of attachment of the base piece (2) is located on a distal side or lateral of the same, the device to implant and assemble with a method that bought thus the steps of: providing the base piece (1) and the base piece (2) of the device anchor the base piece (1) in bone tissue (11) of the patient by positioning in the bone tissue and coupling with mechanical vibration in it for a sufficient time to liquefy at least part of the first liquefiable material and press it into the bone tissue (11), position the base piece (2) with respect to the base piece (1) so that the two places (F, S ) of union are in contact with each other and join the base piece (2) to the base piece (1) by coupling with mechanical vibration in the base piece (2) or the base piece (1) for a sufficient time to liquefy at least part of the second liquefiable material of the first place (F) of connection and let it penetrate the structure of the second place (S) of union.Un dispositivo para implantar y ensamblar en un paciente que comprende una pieza de base (1) que se equipa para ser anclada en tejido óseo (11) con la ayuda de un primer material licuable y vibración mecánica, y una pieza basada (2), q
