AO Research Institute Davos, Davos, Switzerland.
Department of Traumatology and Reconstructive Surgery, BG Trauma Center Tübingen, Eberhard-Karls University of Tübingen, Tübingen, Germany.
Biomed Res Int. 2021 Mar 6;2021:6649712. doi: 10.1155/2021/6649712. eCollection 2021.
Minimally invasive plate osteosynthesis (MIPO) is one of the generally accepted surgical techniques for the treatment of humeral shaft fractures. However, despite the high bone union rate, a variety of complications are still prevailing. Moreover, the current literature lacks data comparing the anterolateral MIPO approach using dynamic compression plates accommodating different numbers of screws. The aim of this study was to analyze the biomechanical performance of comminuted humeral shaft fractures fixed with dynamic compression plates using either two or three screws per fragment.
Six pairs of fresh-frozen human cadaveric humeri from donors aged 66.8 ± 5.2 years were randomized to two paired study groups for simulation of bridge-plated comminuted shaft fracture type AO/OTA 12-C1/2/3 without interfragmentary bony support, using a dynamic compression plate positioned on the anterolateral surface and fixed with two (group 1) or three (group 2) screws per fragment. All specimens underwent nondestructive quasistatic biomechanical testing under lateral bending, anterior bending, axial bending, and torsion in internal rotation, followed by progressively increasing cyclic torsional loading in internal rotation until failure.
Initial stiffness of the plated specimens in lateral bending, anterior bending, axial bending, and torsion was not significantly different between the groups ( ≥ 0.22). However, cycles to 10°, 15°, and 20° torsional deformation and cycles to construct failure were significantly higher in group 2 compared with group 1 ( ≤ 0.03).
From a biomechanical perspective, no significant superiority is identified in terms of primary stability when using two or three screws per fragment for bridge compression plating of comminuted humeral shaft fractures. However, three-screw configurations provide better secondary stability and maintain it with a higher resistance towards loss of reduction under dynamic loading. Therefore, the use of a third screw may be justified when such better secondary stability is required.
微创钢板接骨术（MIPO）是治疗肱骨干骨折的一种普遍接受的手术技术。然而，尽管骨愈合率较高，但仍存在多种并发症。此外，目前的文献缺乏比较使用不同数量螺钉的前外侧 MIPO 入路的资料。本研究旨在分析使用每块骨折 2 枚或 3 枚螺钉固定粉碎性肱骨干骨折的动力加压钢板的生物力学性能。
将 6 对来自年龄为 66.8 ± 5.2 岁的供体的新鲜冷冻人尸体肱骨干随机分为两组配对研究，模拟无骨间支撑的桥接钢板粉碎性骨干骨折 A0/OTA 12-C1/2/3 型，使用前外侧放置的动力加压钢板，每块骨折固定 2 枚（组 1）或 3 枚（组 2）螺钉。所有标本均在侧向弯曲、前弯曲、轴向弯曲和内旋扭转以及随后逐渐增加的内旋扭转循环加载直至失效的情况下进行非破坏性准静态生物力学测试。
在侧向弯曲、前弯曲、轴向弯曲和扭转中，钢板标本的初始刚度在两组之间无显著差异（≥0.22）。然而，组 2 达到 10°、15°和 20°扭转变形的循环次数和达到构建失败的循环次数明显高于组 1（≤0.03）。
从生物力学角度来看，在使用每块骨折 2 枚或 3 枚螺钉进行桥接压缩钢板固定粉碎性肱骨干骨折时，在初始稳定性方面没有明显优势。然而，三螺钉构型提供了更好的二级稳定性，并在动态载荷下保持更高的抗复位丢失能力。因此，当需要更好的二级稳定性时，使用第三枚螺钉是合理的。
