Fig. 3

A combination of an osteotomy and implant-positioning guide (A and B in red) for placement of an angle blade plate. Additional to the cutting slit for the osteotomy (green plane), a chisel slit has been added to the guide design. The chisel slit guides the seating chisel in its direction and depth. A supplementary drilling hole, just above the chiseling slit, has been added for drilling of a K-wire parallel to the chiseling direction. The K-wire serves as a second safety check for the appropriate blade positioning. In C, the intraoperative positioned guide with the placed seating chisel, the asterisk marks the greater trochanter. In D, the angle plate could simply be placed over the reference pins distally and into the pre-chiseled position proximally after the osteotomy to achieve the aimed deformity correction. The asterisk marks the greater trochanter