Reconstruction of the biomechanical transfer path of femoral head necrosis: a subject-specific finite element investigation.

According to Wolff׳s law, the structure and function of bone are interdependent. The disruption of trabeculae in the necrotic femoral head destroys the biomechanical transfer path, increasing the risk of a collapse in the cortical bone. Hence, biomaterials are needed to promote osteogenesis to aid in the reconstruction of a similar biomechanical transfer path that can provide structural and biomechanical support to prevent and delay bone deterioration. Fibular allograft combined with impaction bone grafting (FAIBG) is a hip preservation method that provides both biological repair materials and biomechanical support. This method has been used successfully in the clinical setting, but it still lacks biomechanical insight. In this paper, we aim to provide a biomechanical basis for treatment using FAIBG, we used subject-specific finite element (FE) methods to analyse the biomechanical transfer characteristics of hip models: physiological, pathological and postoperative. The physiological model provided insight into the biomechanical transfer characteristics of the proximal femur. The pathological model showed an abnormal stress distribution that destroyed stress transfer capability. The postoperative model showed that FAIBG can reconstruct the biomechanical transfer path of the femoral head and reduce the risk of a collapse in the cortical bone. In conclusion, FAIBG seems to treat necrosis of the femoral head.