Afshar R, Fong T S, Latifi M Hadi, Kanthan S R, Kamarul T
Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence in Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
J Hand Surg Eur Vol. 2012 Jun;37(5):396-401. doi: 10.1177/1753193411424557. Epub 2011 Oct 21.
The use of bicortical screws to fix metacarpal fractures has been suggested to provide no added biomechanical advantage over unicortical screw fixation. However, this was only demonstrated in static loading regimes, which may not be representative of biological conditions. The present study was done to determine whether similar outcomes are obtained when cyclic loading is applied. Transverse midshaft osteotomies were created in 20 metacarpals harvested from three cadavers. Fractures were stabilised using 2.0 mm mini fragment plates fixed with either bicortical or unicortical screw fixation. These fixations were tested to failure with a three-point bending cyclic loading protocol using an electromechanical microtester and a 1 kN load cell. The mean load to failure was 370 N (SD 116) for unicortical fixation and 450 N (SD 135) for bicortical fixation. Significant differences between these two constructs were observed. A biomechanical advantage was found when using bicortical screws in metacarpal fracture plating.
有人认为，使用双皮质螺钉固定掌骨骨折，与单皮质螺钉固定相比，不会带来额外的生物力学优势。然而，这仅在静态加载条件下得到证实，而静态加载可能无法代表生物学条件。本研究旨在确定施加循环载荷时是否会得到类似结果。从三具尸体上获取20根掌骨，制作横断中轴截骨。骨折采用2.0毫米微型接骨板固定，分别使用双皮质或单皮质螺钉固定。使用机电式微型测试仪和1 kN测力传感器，通过三点弯曲循环加载方案对这些固定方式进行测试直至失效。单皮质固定的平均失效载荷为370 N（标准差116），双皮质固定为450 N（标准差135）。观察到这两种固定方式之间存在显著差异。在掌骨骨折钢板固定中使用双皮质螺钉时发现了生物力学优势。
