An elongated bone screw is provided comprising a distal part and a proximal part both having a leading end and a trailing end, respectively. The trailing end of the distal part includes a tool engagement portion and the leading end of the proximal part includes a distal part engagement portion for an engagement with the tool engagement portion of the distal part. The implant further comprises an assembly element for firmly coupling the distal part and the proximal part when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part.
