Computational modeling of the patient-specific femoral head before and after the treatment

In femoral head necrosis, the cortical shell of the femoral head collapses and buckles into the cancellous bone. The purpose of this study is to explore the biomechanical characteristics of the femoral head and the necrosis region by comparing the results before and after drug treatment. In this paper, we study two patient cases with femoral head necrosis disease and establish the corresponding computational three-dimensional models. The results show that the deformation of the femur decreases slightly after the treatment, the equivalent stress distributes more evenly, and the stress magnitude reduces. The results also reveal that the volume of the necrosis in the femoral head decreases after treatment, the overall necrosis presents relatively lower equivalent stress, and the area with the relatively high equivalent stress is smaller comparing to the necrosis in femoral head before treatment.