Biomechanical Analysis of Window Configuration of Femur under Different Loading Conditions

Background: In surgeries, when making a window in the bone cortex is necessary, a circular window is usually recommended. A review of the literature did not yield any positive evidence indicating the preference for the circular shape under bending and compression loading. Objectives: In this study, we examined this issue using two methods, including software analysis and performing load tests in laboratory. Methods: Windows of different shapes with the same area were made in 40 femoral bones of the same-weight New Zealand rabbits, and then they were put under bending and compression force by a hydraulic device in the laboratory to measure the force required to fracture the bone by a computer. Simultaneously, ANSYS® software was used to simulate the test by the Biomechanics Research Team of the University of Technology. Results: According to the results obtained from software analysis and simulation, under compression and bending loading conditions, the mean fracture force in a trapezoidal shape was more than that in circular, square, and triangular shapes. These results were also confirmed in the experiments. Conclusion: Based on the results, no significant difference was observed between these shapes under the bending force. Moreover, under compression loading, no significant difference was found between trapezoidal and circular shapes.