| 摘要 |
Bone screw, method for producing the threads thereof and drill for drilling holes therefor. The present invention relates to a bone screw, a method for producing the threads of the bone screw and a drill for drilling holes therefor. The bone screw is adapted for implants for fixation of bone fragments at fractures and it comprises a threaded or tapped part (16) which is adapted to be screwed into a bone fragment at the fracture. The threaded part (16) extends backwards from a front end portion (17) of the bone screw (6) to an untapped part (18) thereof and has threads (19) with the same outer diameter (YD). The threads (19) have the same pitch of thread (P) and extend from a core (21). At least front parts of the core (21) closest to the front end portion (17) of the bone screw (6) are conical and have their least diameter (MD) situated at the front end portion (17). The threads (19) have truncated crests (23) and the width (b1-b7) of the crests (23) of the threads (19) increases in backwards direction from the front end portion (17). The width (B1-B6) of grooves (20) between the threads (19) decreases in dependence of the increase in width (b1-b7) of the crests (23) (FIG. 2).
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