Bone anchor with a drilling template connecting to this bone anchor and method for manufacturing the bone anchor and the drilling template

A method for manufacturing at least one bone anchor and a corresponding drilling template, wherein the bone anchor has an anchor plate which is to be fixed with one or several screws provided with screw heads against the surface of a bone, such that the anchor plate has a bone side which is to be connected to the surface of the bone and a free side opposite to said bone side, the method comprising:

• a) generating a three-dimensional digital image of the bone;
• b) selecting, on the basis of this three-dimensional image, a position and orientation for each of said one or several screws for fixing the anchor plate to the surface of the bone as a function of the structure and density of the bone, wherein a borehole with a borehole axis is thus defined for said screws in relation to said bone;
• c) designing, starting from said three-dimensional digital image and the selected position and orientation for said one or several screws, said anchor plate with, for each of said screws, a recess in the anchor plate with an axis which coincides with said borehole axis in order to make it possible for the anchor plate to be fixed to said bone through this recess in the anchor plate by said screws, such that its bone side connects to the surface of the bone, wherein said screws extend in the bone according to the selected position and orientation,
• d) designing the shape of the drilling template so as to be placed against said free side of the anchor plate, and designing said drilling template with, for each of said screws, a cylindrical recess in the drilling template having a central axis for guiding a drill or a cutter,
• wherein said borehole axis for each of the screws for fixing the anchor plate to the surface of the bone coincides with said central axis of the corresponding cylindrical recess of the drilling template and the central axis of the cylindrical recess of the drilling template coincides with the axis of the recess in the anchor plate,
• wherein the diameter of said cylindrical recess of the drilling template is equal to or larger than the diameter of the head of the corresponding screw and larger than the diameter of the corresponding recess of said anchor plate, and
• e) manufacturing the drilling template and the bone anchor according to the designs in steps c)-d).