Stress analysis of the vascularized fibular bone transplantation in large tibia defect reconstruction: A finite element study

Microsurgical vascularized bone graft has been successfully used to treat large tibial defects. The shape, size and length of the fibula make it a popular donor site for most tibia defects. The goal of this study is to numerically analyze the stress distribution in the transferred fibula and to evaluate the nature of the placement of the fibular graft and its relations to failure. A finite element analysis was conducted to investigate the stress distribution and to predict the stress fracture positions in transferred bones. The calculated results matched well with clinical observations. The simulation suggests that those grafts having a lower site transfer exhibit a higher level of stress distribution. The finite element model also suggests that the stress level of an obliquely placed graft is higher than that of a vertically placed graft, especially at the distal tibia-fibula junction. A longer period of protection is therefore recommended for the treatment of a lower site transfer or an obliquely placed grafted bone to avoid bone stress fracture.