Li Zhengdong, Zhang Jianhua, Wang Jinming, Huang Ping, Zou Donghua, Chen Yijiu
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China.
Shanghai Key laboratory of Forensic Medicine, Academy of Forensic Science, Ministry of Justice, Shanghai, China.
Forensic Sci Res. 2021 May 20;7(3):518-527. doi: 10.1080/20961790.2021.1875582. eCollection 2022.
Ankle injuries are common in forensic practice, which are mainly caused by falling and traffic accidents. Determining the mechanisms and manners of ankle injuries is a critical and challenging problem for forensic experts. The identification of the injury mechanism is still experience-based and strongly subjective. There also lacks systematic research in current practice. In our study, based on the widely used Total Human Model of Safety 4.0 (THUMS 4.0), we utilized the finite element (FE) method to simulate ankle injuries caused by falls from different heights (5 m, 10 m and 20 m) with different landing postures (natural posture, inversion, eversion, plantar-flexion and dorsi-flexion) and injuries caused by impacts from different directions (anterior-posterior, lateral-medial and posterior-anterior) with different speeds (10 m/s, 15 m/s and 20 m/s) at different sites (ankle and lower, middle and upper sections of leg). We compared the injury morphology and analyzed the mechanisms of ankle injuries. The results showed that falling causes a specific compression fracture of the distal tibia, while fractures of the tibia and fibula diaphysis and ligament injuries caused by falling from a lower height or inversion, planter flexion or dorsiflexion at a large angle are not distinguishable from the similar injury patterns caused by impact on the middle and upper segments of the leg. No obvious compression fracture of the tibia distal was caused by the impacts, whereas ligament injuries and avulsion fractures of the medial or lateral condyle and fractures of the diaphysis of the tibia and fibula were observed. Systematic studies will be helpful in reconstructing the ankle injury processes and analyzing the mechanisms in forensic practice, providing a deeper understanding of ankle injury mechanisms for forensic experts.
踝关节损伤在法医实践中很常见，主要由跌倒和交通事故引起。确定踝关节损伤的机制和方式对法医专家来说是一个关键且具有挑战性的问题。损伤机制的识别仍然基于经验且主观性很强。目前的实践中也缺乏系统的研究。在我们的研究中，基于广泛使用的全人类安全模型4.0（THUMS 4.0），我们利用有限元（FE）方法模拟了从不同高度（5米、10米和20米）以不同着地姿势（自然姿势、内翻、外翻、跖屈和背屈）跌倒导致的踝关节损伤，以及在不同部位（踝关节以及小腿的下、中、上段）以不同速度（10米/秒、15米/秒和20米/秒）从不同方向（前后、内外侧和后前）撞击导致的损伤。我们比较了损伤形态并分析了踝关节损伤的机制。结果表明，跌倒会导致胫骨远端特定的压缩性骨折，而较低高度跌倒或大角度内翻、跖屈或背屈导致的胫腓骨干骨折和韧带损伤与小腿中、上段受到撞击导致的类似损伤模式无法区分。撞击未导致胫骨远端明显的压缩性骨折，而观察到了韧带损伤以及内外侧髁的撕脱性骨折和胫腓骨干骨折。系统的研究将有助于在法医实践中重建踝关节损伤过程并分析损伤机制，为法医专家提供对踝关节损伤机制更深入的理解。
