Haraguchi Naoki, Armiger Robert S
Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland, USA.
J Bone Joint Surg Am. 2009 Apr;91(4):821-9. doi: 10.2106/JBJS.G.01288.
Researchers have found it difficult to recreate a Lauge-Hansen supination-external rotation-type ankle fracture in experimental settings. We hypothesized that a pronation-external rotation mechanism could cause both distal, short oblique and high fibular fractures and that the fracture type would be affected by associated, laterally directed forces applied to the foot. Methlods: Twenty-three cadaver ankles were subjected to fracture loading that replicated the Lauge-Hansen pronation-external rotation mechanism with or without applying an external lateral force. In Phase I, an axial load was applied to fifteen specimens mounted on a materials testing machine. Each foot was rotated externally to failure. In Phase II, eight specimens were tested according to the Phase-I protocol, but external forces were applied laterally at the foot to increase the abduction moment at the ankle. Load and position versus time curves were recorded and were correlated with video image data to establish the sequence of failure of specific anatomic structures.
Eight specimens tested in Phase I sustained an oblique fracture of the distal end of the fibula with both medial and posterior injuries that occurred after the fibular fracture. Increasing the external lateral force and hence the abduction moment within the ankle (Phase II) resulted in three of eight specimens sustaining a high fibular fracture with a reversed fracture line (anterosuperior to posteroinferior) and/or a comminuted high fibular fracture. The distribution of traditional pronation-external rotation-type fractures differed significantly between Phase I and Phase II (p=0.032).
This study generated counterexamples to the Lauge-Hansen classification system by showing that a short oblique fracture of the distal end of the fibula can occur with the foot in the pronated position. Furthermore, a high fibular fracture was recreated by increasing the abduction moment at the ankle.
研究人员发现在实验环境中重现Lauge-Hansen旋前-外旋型踝关节骨折很困难。我们推测旋前-外旋机制可导致腓骨远端短斜形骨折和高位骨折，并且骨折类型会受到施加于足部的相关侧向力的影响。方法：对23个尸体踝关节施加骨折负荷，模拟Lauge-Hansen旋前-外旋机制，施加或不施加外侧外力。在第一阶段，对安装在材料试验机上的15个标本施加轴向负荷。每只脚向外旋转至骨折。在第二阶段，根据第一阶段的方案对8个标本进行测试，但在足部外侧施加外力以增加踝关节的外展力矩。记录负荷和位置与时间的曲线，并与视频图像数据相关联，以确定特定解剖结构的骨折顺序。
在第一阶段测试的8个标本中，腓骨远端出现斜形骨折，同时伴有内侧和后侧损伤，这些损伤发生在腓骨骨折之后。增加外侧外力，从而增加踝关节内的外展力矩（第二阶段），导致8个标本中的3个出现高位腓骨骨折，骨折线方向相反（从前上到后下）和/或粉碎性高位腓骨骨折。第一阶段和第二阶段传统旋前-外旋型骨折的分布有显著差异（p=0.032）。
本研究通过表明足部处于旋前位时可发生腓骨远端短斜形骨折，对Lauge-Hansen分类系统产生了反例。此外，通过增加踝关节的外展力矩重现了高位腓骨骨折。
