A device for attaching a flat and flexible band on at least one bone part, comprising the band having two end portions, a rigid base body crossed by an opening, and a retaining part that can be inserted in the opening. The retaining part is at least partially in the shape of a squeezable wedge comprising a central bore for passage of the end portions facing the flexible band, the bore having a transverse cross-section that can be deformed between a first cross-section for free passage of the end portions when the part has not been inserted in the opening and a second cross-section for locking the end portions by compression when the part is entirely or substantially entirely inserted in the opening.