[Experimental studies in weakening the stability of the trochanter major by lateral fenestration]

A major disadvantage of the usual 130 degree angle plates when handling the fracture of the neck of the femur is the fact that the lateral corticalis of the femur is almost completely interrupted by the broad window at a biomechanical important and highly strained location. This often leads to the complications such as the breaking off of the greater trochanter or lack of stability etc. The experiment examines ten pairs of human femora for a decrease of stability, which results from the lateral fenestration for the osteosynthesis. One of the two bones out of a pair received a slit at a right angle concerning the axis of the femur, the other one a round hole. The slit was made into the proximal lateral femur as if preparing for the installation of a 130 degree angle plate. On the corresponding spot of the second bone a round hole was drilled. The remaining stability of the compact bone was measured by experimental pulling on the greater trochanter. Under the assumption that left and right femur have about the same stability, which was proven in one of the experiments, a significant disadvantage was found for the relatively wide slit.