Foot Ankle Int. 2012 Jul;33(7):548-52. doi: 10.3113/FAI.2012.0548.
Ankle fractures are the most common fracture treated by orthopaedic surgeons in the United States. Isolated lateral malleolus fractures are treated nonoperatively, while associated deltoid disruption injuries are unstable and usually treated by fixation of the fracture. Various stress radiographs and MRI have been used to determine deltoid competency and the subsequent need for operative stabilization of lateral malleolus fractures. To date, no standardization of stress radiography has been performed. The aim of this study was to evaluate the ability of weightbearing ankle X-rays to determine stability and their reliability.
This study sought to utilize simulated weightbearing radiography as a potential method to determine the need for lateral malleolus fixation. Twelve cadaveric ankle specimens were tested by obtaining ankle mortise radiographs for interpretation of medial clear space. Each ankle was tested with 0, 25, 36, and 50 kg of axially applied weight. The groups of measurements obtained were: intact ankles (Group A), ankles with an isolated oblique fibular osteotomy (Group B), and osteotomized ankles after complete deltoid ligament transaction (Group C). Three authors measured the medial clear space for every ankle using PACSR software. Instability of the ankle mortise was defined as medial clear space widening of greater than 2 mm from the intact ankle.
An isolated lateral malleolus fracture (Group B) and a lateral malleolus fracture with an incompetent deltoid ligament (Group C) showed no statistical medial clear space widening with simulated axial weightbearing radiography when compared to intact ankles (Group A). ANOVA's between Group A and B had p < 0.001, and between Group A and C of p < 0.001.
Our model did not find instability with an osteotomized fibula and a disrupted deltoid.
This study suggests a weightbearing radiograph of an isolated lateral malleolus fracture cannot determine deltoid ligament integrity and thus need for fibular operative fixation.
在美国，足踝部骨折是骨科医生最常治疗的骨折类型。单纯外踝骨折采用非手术治疗，而伴有三角韧带撕裂的骨折则不稳定，通常需要固定骨折。各种应力量线片和 MRI 已被用于确定三角韧带的完整性，以及随后是否需要手术固定外踝骨折。迄今为止，还没有对线片进行标准化。本研究旨在评估负重踝关节 X 线片确定稳定性的能力及其可靠性。
本研究试图利用模拟负重放射摄影作为一种潜在的方法来确定是否需要固定外踝。对 12 例尸体踝关节标本进行测试，通过获得踝关节正位片来测量内侧间隙。每个踝关节分别施加 0、25、36 和 50kg 的轴向负荷。获得的测量组包括：完整踝关节（A 组）、单纯腓骨斜行切开（B 组）和完全切断三角韧带后的切开踝关节（C 组）。三位作者使用 PACSR 软件测量每只踝关节的内侧间隙。距骨正位片显示内侧间隙增宽超过 2mm 被定义为踝关节不稳定。
与完整踝关节（A 组）相比，单纯外踝骨折（B 组）和外踝骨折伴三角韧带不连续（C 组）在模拟轴向负重放射摄影时，内侧间隙未见统计学意义上的增宽。A 组和 B 组之间的 ANOVA 有 p<0.001，A 组和 C 组之间的 p<0.001。
我们的模型在外踝切开和三角韧带撕裂的情况下没有发现不稳定。
本研究表明，单纯外踝骨折的负重 X 线片不能确定三角韧带的完整性，因此不需要腓骨手术固定。
