Abstract: The invention is related to a method for the determination of reduction parameters for the subsequent adjustment of a reduction device to reduce the fragments of a fractured bonee. The method comprises: measuring points on the surfaces of the corresponding bones of interest at the patient's left and right side of the body; establishing a plane of symmetry containing an anterior-posterior axis and a proximal-distal axis; generating a mirror image of the patient's non-fractured bone symmetrically to the plane of symmetry; and determining the reduction parameters by comparison of the coordinates of the points at the fractured bone with the coordinates of the points within the mirror image.

Abstract: The invention is related to an intramedullary nail for fixation of a fractured bone having a medullary canal. The intramedullary nail may comprise a first radially expandable section provided in a proximal section adjacent to the head of the intramedullary nail, a second radially expandable section provided in the distal section adjacent to the tip of the intramedullary nail, and a non-expandable middle section provided between said two radially expandable sections of the intramedullary nail. The head may provide a distraction mechanism, by means of which said two radially expandable sections are distractible transverse to said longitudinal axis.

Abstract: The invention is related to a method for the determination of reduction parameters for the subsequent adjustment of a reduction device to reduce the fragments of a fractured bone. The method comprises: measuring points on the surfaces of the corresponding bones of interest at the patient's left and right side of the body; establishing a plane of symmetry containing an anterior-posterior axis and a proximal-distal axis; generating a mirror image of the patient's non-fractured bone symmetrically to the plane of symmetry; and determining the reduction parameters by comparison of the coordinates of the points at the fractured bone with the coordinates of the points within the mirror image.

Abstract: The invention is related to an intramedullary nail for fixation of a fractured bone having a medullary canal. The intramedullary nail may comprise a first radially expandable section provided in a proximal section adjacent to the head of the intramedullary nail, a second radially expandable section provided in the distal section adjacent to the tip of the intramedullary nail, and a non-expandable middle section provided between said two radially expandable sections of the intramedullary nail. The head may provide a distraction mechanism, by means of which said two radially expandable sections are distractible transverse to said longitudinal axis.

Abstract: A bone screw (1) has a screw head (2), a screw tip (11), and a shaft (5) with a thread (8,14). The threaded segment (6,7) of the shaft (5) has a head-end, essentially cylindrical first shaft section (6) with minor diameter d.sub.1 (16), and a tip-end second shaft segment (7) that is connected with the first shaft segment (6) and which has a smaller minor diameter d.sub.2 (17). The thread (8,14) in the two shaft segments (6,7) has the same pitch (10,12).