Background

Displaced midshaft fractures are the most common surgically treated clavicle fractures. However, they are associated with high complication rates following plating due to fixation failure in terms of plate breakage, screw breakage and/or screw loosening. The aim of this study was to compare the biomechanical competence of three different plating techniques for fixation of displaced midshaft clavicle fractures.

Methods

Displaced midshaft fractures type 2B according to the Robinson classification were simulated by standardized osteotomy gap in 18 synthetic clavicles, assigned to three groups (n = 6) for plating with either superiorly placed Dynamic Compression Plate (width/thickness 11.0/4.0 mm), locked Superior Anterior Clavicle Locking Compression Plate (width/thickness 10.2/2.0 mm), or two non-locked Reconstruction Plates placed superiorly and anteriorly (width/thickness 10.0/2.8 mm). Each specimen was cyclically tested at 3 Hz under craniocaudal cantilever bending, superimposed with torsion around the shaft axis over 720′000 cycles or until failure occurred. The latter was defined by plate breakage, screw breakage or screw loosening.

Findings

Initial construct stiffness (N/mm) and cycles to failure in group Reconstruction Plates (22.30 ± 4.07; 712′778 ± 17′691) were significantly higher compared with both groups Compression Plate (12.53 ± 2.09; 348′541 ± 212′941) and Locking Plate (4.19 ± 0.46; 19′536 ± 3′586), p ≤ 0.019. In addition, these two outcomes were significantly higher in group Compression Plate versus Locking Plate, p ≤ 0.029.

Interpretation

Double plating of unstable midshaft clavicle fractures with reconstruction plates seems to provide superior fixation stability under dynamic loading, when compared to single compression or locked plating, whereas the latter is associated with inferior performance.

中文翻译：

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与单个钢板相比，两个重建钢板可提供移位的中轴锁骨骨折优越的稳定性–生物力学研究

背景

移位的中轴骨折是最常见的经手术治疗的锁骨骨折。然而，由于在板断裂，螺钉断裂和/或螺钉松动方面的固定失败，它们与电镀后的高并发症发生率有关。这项研究的目的是比较三种不同的钢板技术固定移位中轴锁骨骨折的生物力学能力。

方法

通过标准的截骨间隙在18个合成的锁骨中模拟根据Robinson分类的2B型移位中轴骨折，将其分为三组（n  = 6），使用位置优越的动态加压钢板（宽度/厚度11.0 / 4.0 mm）进行锁定锁骨前上加压钢板（宽度/厚度10.2 / 2.0毫米），或上下放置两个非锁定重建钢板（宽度/厚度10.0 / 2.8毫米）。每个样本在颅尾悬臂弯曲下以3 Hz的频率进行循环测试，并在720'000个循环内或在绕轴扭转之前叠加扭转，直到发生故障。后者的定义是板断裂，螺丝断裂或螺丝松动。

发现

组重建板的初始构造刚度（N / mm）和破坏循环（22.30±4.07; 712'778±17'691）与两组压迫板（12.53±2.09; 348'541±212'941）相比均显着更高）和锁定板（4.19±0.46; 19'536±3'586），p  ≤0.019。此外，这些两个结果在组加压接骨板与锁定钢板，均显著更高p  ≤0.029。

解释

与单次加压或锁定钢板相比，用重建钢板双钢板固定不稳定的中轴锁骨骨折在动态载荷下似乎提供了优越的固定稳定性，而后者则具有较差的性能。