A device for establishing an anchorage in tissue with the aid of mechanical vibration and a material having thermoplastic properties and being liquefiable by the mechanical vibration, the device comprising: a vibrating element , a proximal end of the vibrating element being suitable for being coupled to a vibration source and the vibrating element being capable of transmitting vibration generated by the vibration source to a distal end of the vibrating element , and a tube-shaped liquefiable part comprising the liquefiable material and having an inner and an outer cross section, the device further comprising a guide element wherein • the guide element is a separate element and the device comprises an axial recess (51.5) in the vibrating element , which recess (51.5) is able to accommodate a proximal portion of the guide element , or • the vibrating element comprises a distal portion (51.2) of a smaller cross section, a proximal portion (51.1) of a larger cross section and a shoulder (51.3) therebetween, wherein the guide element is the distal portion (51.2) of the smaller cross section and wherein said distal portion has a constant cross-section, wherein the guide element (51.2, 55) is dimensioned in a manner that a distal end portion of the guide element can extend form a proximal side of the tube-shaped liquefiable part into the tube-shaped liquefiable part , and wherein the liquefiable part is fixed to the guide element (51.2, 55) or sits thereon. a vibrating element , a proximal end of the vibrating element being suitable for being coupled to a vibration source and the vibrating element being capable of transmitting vibration generated by the vibration source to a distal end of the vibrating element , and a tube-shaped liquefiable part comprising the liquefiable material and having an inner and an outer cross section, the device further comprising a guide element wherein • the guide element is a separate element and the device comprises an axial recess (51.5) in the vibrating element , which recess (51.5) is able to accommodate a proximal portion of the guide element , or • the vibrating element comprises a distal portion (51.2) of a smaller cross section, a proximal portion (51.1) of a larger cross section and a shoulder (51.3) therebetween, wherein the guide element is the distal portion (51.2) of the smaller cross section and wherein said distal portion has a constant cross-section, • the guide element is a separate element and the device comprises an axial recess (51.5) in the vibrating element , which recess (51.5) is able to accommodate a proximal portion of the guide element , or • the vibrating element comprises a distal portion (51.2) of a smaller cross section, a proximal portion (51.1) of a larger cross section and a shoulder (51.3) therebetween, wherein the guide element is the distal portion (51.2) of the smaller cross section and wherein said distal portion has a constant cross-section, wherein the guide element (51.2, 55) is dimensioned in a manner that a distal end portion of the guide element can extend form a proximal side of the tube-shaped liquefiable part into the tube-shaped liquefiable part , and wherein the liquefiable part is fixed to the guide element (51.2, 55) or sits thereon. <EOS>