Intramedullary locking bone screw for fixing the metatarsophalangeal joint of the big toe in foot surgery

An intramedullary locking bone screw for fixing the metatarsophalangeal joint of the big toe in foot surgery which is completely receivable in the bone and which extends along a longitudinal axis, comprising a first outer threaded section having a first thread pitch and having at least one second outer threaded section having a second thread pitch different from the first thread pitch, wherein at least one first fixing passage is provided for the reception of fixation means in the second outer threaded section, the passage extending at an angle with respect to the longitudinal axis and passing through the bone screw;

• wherein a second fixing passage for the reception of fixing means is provided which has an axial spacing with respect to the first fixing passage, which is arranged in the first outer threaded section and which passes through the bone screw;
• wherein a first longitudinal middle axis of the first fixing passage is arranged rotated by an angle with respect to a second longitudinal middle axis of the second fixing passage in the circumferential direction of the bone screw;
• wherein the first outer threaded section is arranged in the region of a rear bone screw end having a drive and a smaller pitch than the second outer threaded section;
• wherein a core diameter of the bone screw in the region of the first outer threaded section changes over the longitudinal extent of the bone screw, namely tapers from the rear to the front;
• wherein the core diameter of the bone screw in the region of the first outer threaded section is conically contoured, wherein the conical shape of the core continues starting from a cylindrical section up to the axial rear end of the bone screw;
• wherein the conical angle of the conical section, measured between a conical jacket surface and the longitudinal axis of the screw, amounts to between approximately 2° and 6°;
• and
• wherein the first outer threaded section has a cylindrical sleeve contour.