Abstract：
BACKGROUND: This biomechanical study aimed to test if the fixation of the posterior malleolus (PM) only with screws inserted from posterior to anterior (PA) restores stability comparable with the natural condition. The extent of stability was also compared with that of anterior to posterior (AP) screw osteosynthesis (OS) with an additional syndesmotic screw (SS).
METHODS: First, the stability of the upper ankle joint in seven pairs of intact lower legs were examined. Subsequently, half of the lower legs were treated with PA screw fixation of a PM fracture without SS and the other half with AP screw fixation with additional tricortical SS.
RESULTS: PA OS without SS showed significantly more diastasis (p = 0.027). The AP OS with an SS revealed a diastasis that was comparable with the intact condition (p = 0.797). The use of SS led to significantly higher stability compared to OS without SS (p = 0.019).
CONCLUSIONS: The Fixation of the PM alone without an additional syndesmotic screw cannot achieve intact upper ankle stability. Fixation of a PM fracture with an SS helps in nearly achieving the natural condition.
METHODS: First, the stability of the upper ankle joint in seven pairs of intact lower legs were examined. Subsequently, half of the lower legs were treated with PA screw fixation of a PM fracture without SS and the other half with AP screw fixation with additional tricortical SS.
RESULTS: PA OS without SS showed significantly more diastasis (p = 0.027). The AP OS with an SS revealed a diastasis that was comparable with the intact condition (p = 0.797). The use of SS led to significantly higher stability compared to OS without SS (p = 0.019).
CONCLUSIONS: The Fixation of the PM alone without an additional syndesmotic screw cannot achieve intact upper ankle stability. Fixation of a PM fracture with an SS helps in nearly achieving the natural condition.
摘要：
背景：这项生物力学研究旨在测试仅使用从后到前（PA）插入的螺钉固定后踝（PM）是否恢复了与自然条件相当的稳定性。还将稳定性的程度与前后（AP）螺钉接骨术（OS）和额外的联合滑膜螺钉（SS）进行了比较。
方法：首先，检查了七对完整小腿的上踝关节的稳定性。随后，小腿的一半用PA螺钉固定治疗无SS的PM骨折，另一半用AP螺钉固定并附加三皮质SS。
结果：无SS的PAOS显示明显更多的舒张（p=0.027）。具有SS的APOS显示出与完整条件相当的舒张(p=0.797)。与没有SS的OS相比,使用SS导致显著更高的稳定性(p=0.019)。
结论：单独固定PM而没有额外的联合韧带螺钉不能获得完整的上踝关节稳定性。用SS固定PM骨折有助于几乎达到自然状态。
方法：首先，检查了七对完整小腿的上踝关节的稳定性。随后，小腿的一半用PA螺钉固定治疗无SS的PM骨折，另一半用AP螺钉固定并附加三皮质SS。
结果：无SS的PAOS显示明显更多的舒张（p=0.027）。具有SS的APOS显示出与完整条件相当的舒张(p=0.797)。与没有SS的OS相比,使用SS导致显著更高的稳定性(p=0.019)。
结论：单独固定PM而没有额外的联合韧带螺钉不能获得完整的上踝关节稳定性。用SS固定PM骨折有助于几乎达到自然状态。
