The invention relates to an intramedullary locking bone screw for fixing the metatarsophalangeal joint of the big toe in foot surgery that can be completely received in the bone, said locking bone screw extending along a longitudinal axis (L), with a first outside thread section (6) having a first thread pitch and with at least one second outside thread section (7), preferably designed to be self-tapping, having a pitch that is different from the first thread pitch. According to the invention, at least one fixing channel (K1) penetrating the bone screw (1) for receiving fixing means is provided in the second outside thread section (7), extending at an angle, preferably perpendicular in relation to the longitudinal axis (L), and a second fixing channel (K2) penetrating the bone screw (1) arranged at an axial distance from the first fixing channel (K1) in the outside thread section (6) for receiving fixing means is provided in the first outside thread section, and a first longitudinal centre axis of the first fixing channel (K1) is arranged offset in the circumferential direction of the bone screw (1) at an angle, preferably 90° in relation to a second longitudinal centre axis of the second fixing channel (K2).