Numerical modelling of hip fracture patterns in human femur

[EN] Background and Objective: Hip fracture morphology is an important factor determining the ulterior surgical repair and treatment, because of the dependence of the treatment on fracture morphology. Although numerical modelling can be a valuable tool for fracture prediction, the simulation of femur fracture is not simple due to the complexity of bone architecture and the numerical techniques required for simulation of crack propagation. Numerical models assuming homogeneous fracture mechanical properties commonly fail in the prediction of fracture patterns. This paper focuses on the prediction of femur fracture based on the development of a finite element model able to simulate the generation of long crack paths. Methods: The finite element model developed in this work demonstrates the capability of predicting fracture patterns under stance loading configuration, allowing the distinction between the main fracture paths: intracapsular and extracapsular fractures. It is worth noting the prediction of different fracture patterns for the same loading conditions, as observed during experimental tests. Results and conclusions: The internal distribution of bone mineral density and femur geometry strongly influences the femur fracture morphology and fracture load. Experimental fracture paths have been analysed by means of micro-computed tomography allowing the comparison of predicted and experimental crack surfaces, confirming the good accuracy of the numerical model.The authors are indebted to University Complutense of Madrid and to the radiological team of the Hospital Universitario Infanta Leonor for supporting the experimental work on human bones included in this paper. The micro-CTs were performed in the Micro-Computed Tomography laboratory at CENIEH facilities with the collaboration of CENIEH staff. The authors gratefully acknowledge the funding support received from the Spanish Ministry of Economy and Competitiveness and the FEDER operation program for funding the projects DPI2013-46641-R, DPI2017-89197-C2-1-R, DPI2017-89197-C2-2-R, RTC-2015-3887-8 and the Generalitat Valenciana through theproject Prometeo/2016/007. The authors also acknowledge the funding support received from the Fundacion Espanola de Investigacion Osea y del Metabolismo Mineral through the 2018 research fellowship program.Marco, M.; Giner Maravilla, E.; Caeiro-Rey, JR.; Miguélez, MH.; Larrainzar-Garijo, R. (2019). Numerical modelling of hip fracture patterns in human femur. Computer Methods and Programs in Biomedicine. 173:67-75. https://doi.org/10.1016/j.cmpb.2019.03.010S677517