[Dynamic stressing of petrochanterically osteotomized femurs treated with endoprostheses (author's transl)]

In the treatment of pertochanteric fractures of the femur, the use of a hip joint prosthesis is indicated in exceptional cases for patients of advanced age. Mechanical testing of the combined system (osteotomized bone-cement-prosthesis) reveals high resistance to stress. A report is presented on stress tests on pertrochanterically osteotomized cadaver femurs which have been treated with endoprostheses. Dynamic stressing was done in four stages up to a maximal force of 2050 N. The resulting movement was measured medially and laterally along the osteotomy fissure. In the medial area it was between 0 and 0.06 mm, and in the lateral between 0 and 0.2 mm. The mechanical stability of this combined system seems to be higher than other surgical methods (Ender-nailing, combined osteosynthesis with bone cement and angle plate). Its load bearing capacity is substantially greater than that of the physiological system.