BACKGROUND This study aims to investigate the malreduction of syndesmosis and its effects on stability. METHODS The biomechanical tests, including the three-dimensional (3D) displacement of the syndesmotic incisura, fibular rotation angle, and torque resistance, were performed on six cadaver legs. These specimens were first tested intact (intact group), then cut all the syndesmotic ligaments and fixed in anatomical position (anatomical model group) and test again. After that, syndesmosis was fixed in 1 cm malreduction (anterior and posterior displacement group) to do the same test. RESULTS In internal or external load, there were significant differences in torque resistance and fibular rotation angle (internal t = 2.412, P = 0.036; external t = 2.412, P = 0.039) between the intact and post-malreduction groups. In internal rotation load, there were significant differences in sagittal displacement between the intact and post-malreduction groups (P = 0.011), and between the anatomical and post-malreduction groups (P = 0.020). In external rotation load, significant differences existed between the intact and ant-malreduction group (P = 0.034) in sagittal (anterior-posterior) displacement. Significant differences also existed between the intact and post-malreduction groups (P = 0.013), and between the anatomical and post-malreduction groups (P = 0.038) in coronal (medial-lateral) displacement. CONCLUSIONS Malreduction in different conditions does affect the stability of the syndesmotic fixation. The result of the study may reveal the biomechanical mechanism of poor clinical outcome in syndesmosis malreduction patients and pathological displacement patterns of the ankle under syndesmotic malreduction conditions. LEVEL OF EVIDENCE III.

中文翻译：

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降膜下融合不良可能会降低固定稳定性：一项生物力学研究。

背景技术本研究旨在研究恶性合成病的减少及其对稳定性的影响。方法对六个尸体腿进行了生物力学测试，包括下颌切牙的三维（3D）位移，腓骨旋转角度和抗扭力。首先对这些标本进行完整测试（完整组），然后切下所有韧带，并固定在解剖位置（解剖模型组），然后再次进行测试。此后，在1 cm畸形复位（前移位和后移位组）中固定结缔组织以进行相同的测试。结果在内部或外部负荷方面，完整和复位后组之间的扭矩阻力和腓骨旋转角度存在明显差异（内部t = 2.412，P = 0.036；外部t = 2.412，P = 0.039）。在内部旋转负载下 完整和复位后组之间的矢状位位移有显着差异（P = 0.011），解剖组和复位后组之间的矢状位移有显着差异（P = 0.020）。在外部旋转载荷下，矢状位（前后）位移在完整组和蚂蚁复位组之间存在显着差异（P = 0.034）。完整的和复位后的组之间（P = 0.013）以及解剖和复位后的组（P = 0.038）在冠状（内侧-外侧）移位方面也存在显着差异。结论在不同情况下的畸形复位确实会影响下颌骨联合固定的稳定性。研究结果可能揭示了在皮下病变不良的患者中，临床效果差的生物力学机制以及踝关节的病理移位模式。证据级别III。