Biomechanical Role of Fibula in Lower Limbs: a Fracture Mechanics Analysis

Abstract Background Fibular grafting is widely used in the treatment of various bone nonunion and bone defect because of its good therapeutic effect. Besides, partial fibular resection has also been used as a treatment for fibular tumors, injuries, etc. However, fibula plays an important role in the biomechanics of the lower limbs. Some experts have used cadaver specimens to study these aspect. In this study, the biomechanical effects of fibula in lower limbs were researched based on mechanics analysis.Methods The CT image data of a middle-aged male normal knee joint were selected. The tibia and fibula were extracted by CT-bone function in Mimics software, and the 3D model of tibia and fibula was obtained. The model was imported into 3-matic and LS-DYNA software to smooth the surface, mesh, define material properties, set failure parameters and interface properties, and set vertical loads and boundary conditions. The tibial fractures in both models were calculated to evaluate the biomechanical role of the fibula in the lower leg.Results The validity of the model was verified, and the fibula load condition was similar to the previous references. In the model with fibula support, the fracture load of the tibia was 78.5KN, the initial fracture time was 0.67164S, and the complete fracture time was 0.73225S. The fibula distributes about 7% of the load on the lower leg. In the fibula defect model, the fracture load of tibia was 73.5KN, the initial fracture time was 0.54034S, and the complete fracture time was 0.61105S.Conclusions Fibula plays an irreplaceable biomechanical role in the process of lower limb load-bearing, which is worthy of clinical attention. Meanwhile, LS-DYNA can be used as an effective tool for bone fracture and numerical analysis.