关键词: 法医病理学, 下肢交通伤, 有限元模型, 损伤重建

Abstract:

Objective A detailed FE （finite element） model of human lower limb was developed to explore the mechanism of injury suffering from rolling and impact， and to reconstruct a real case with the developed model. Methods Human lower limb consists of long bones， patella， menisci， knee ligaments and soft tissues. They were reconstructed by Mimics software on the basis of CT scans of a victim. The model was divided by structural grid approach， and the material properties of different parts were defined according to the literature data. The developed FE model was validated by three points bending tests of long bones， thigh and leg. Three different loading conditions including rolling and impact at low， medium and high speed were applied to explore the possible injury mechanism of a real case. Results A FE model of lower limb was developed， and it is mainly composed of hexahedral elements. The peak forces， maximum bending moments and history curves of the model in tests were agreed with the data in literatures. Under the running over condition， the segmental fracture pattern could be formed. Femur fracture pattern and mechanism were similar to the actual case of being run over by a wheel. Conclusion The study shows the method can be applied to explore possible mechanisms of lower limb fractures in forensic cases. The model can also help to determine the possible loading conditions.

Key words: forensic pathology, lower limb traffic injury, finite element model, injury reconstruction