Xiong Yan, Zhao Xueliang, Xiang Hongyi, Wang Yunjiao, Liao Zhikang, Zhu Xiyan, Zhao Hui
Department of Orthopedics, Daping Hospital and the Research Institute of Surgery, Third Military Medical University, Chongqing 400042, China.
Institute for Traffic Medicine, State Key Laboratory of Trauma, Burns & Combined Wound, Third Military Medical University, Chongqing 400042, China.
Appl Bionics Biomech. 2018 Aug 5;2018:1407345. doi: 10.1155/2018/1407345. eCollection 2018.
Knee joint collision injuries occur frequently in military and civilian scenarios, but there are few studies assessing longitudinal impacts on knee joints. In this study, the mechanical responses and damage characteristics of knee longitudinal collisions were investigated by finite element analysis and human knee impact tests.
Based on a biocollision test plateau, longitudinal impact experiments were performed on 4 human knee joints (2 in the left knee and 2 in the right knee) to measure the impact force and stress response of the bone. And then a finite element model of knee joint was established from the Chinese Visible Human (CVH), with which longitudinal impacts to the knee joint were simulated, in which the stress response was determined. The injury response of the knee joint-sustained longitudinal impacts was analyzed from both the experimental model and finite element analysis.
The impact experiments and finite element simulation found that low-speed impact mainly led to medial injuries and high-speed impact led to both medial and lateral injuries. In the knee joint impact experiment, the peak flexion angles were 13.8° ± 1.2, 30.2° ± 5.1, and 92.9° ± 5.45 and the angular velocities were 344.2 ± 30.8 rad/s, 1510.8 ± 252.5 rad/s, and 9290 ± 545 rad/s at impact velocities 2.5 km/h, 5 km/h, and 8 km/h, respectively. When the impact velocity was 8 km/h, 1 knee had a femoral condylar fracture and 3 knees had medial tibial plateau fractures or collapse fractures. The finite element simulation of knee joints found that medial cortical bone stress appeared earlier than the lateral peak and that the medial bone stress concentration was more obvious when the knee was longitudinally impacted.
Both the experiment and FE model confirmed that the biomechanical characteristics of the injured femur and medial tibia are likely to be damaged in a longitudinal impact, which is of great significance for the prevention and treatment of longitudinal impact injuries of the knee joint.
膝关节碰撞伤在军事和民用场景中均频繁发生，但评估其对膝关节长期影响的研究较少。本研究通过有限元分析和人体膝关节冲击试验，研究膝关节纵向碰撞的力学响应和损伤特征。
基于生物碰撞试验平台，对4个膝关节（左膝2个，右膝2个）进行纵向冲击实验，测量骨骼的冲击力和应力响应。然后根据中国可视化人体（CVH）建立膝关节有限元模型，模拟膝关节的纵向冲击，确定应力响应。从实验模型和有限元分析两方面分析膝关节承受纵向冲击的损伤响应。
冲击实验和有限元模拟发现，低速冲击主要导致内侧损伤，高速冲击导致内侧和外侧均损伤。在膝关节冲击实验中，冲击速度分别为2.5km/h、5km/h和8km/h时，峰值屈曲角度分别为13.8°±1.2、30.2°±5.1和92.9°±5.45，角速度分别为344.2±30.8rad/s、1510.8±252.5rad/s和9290±545rad/s。当冲击速度为8km/h时，1例膝关节出现股骨髁骨折，3例膝关节出现胫骨内侧平台骨折或塌陷骨折。膝关节有限元模拟发现，内侧皮质骨应力比外侧峰值出现更早，膝关节纵向冲击时内侧骨应力集中更明显。
实验和有限元模型均证实，纵向冲击时股骨和胫骨内侧的生物力学特征可能受损，这对膝关节纵向冲击伤的防治具有重要意义。
