Bullock Robert S, Coury John G, Liakos Brendan, Huish Eric G
Valley Consortium for Medical Education, 1400 Florida Ave Suite 200, Modesto, CA, 95350, USA.
J Orthop. 2024 Sep 16;61:43-46. doi: 10.1016/j.jor.2024.09.013. eCollection 2025 Mar.
Far cortical locking (FCL) is a concept of locking plate fixation with reduced stiffness and symmetric micromotion to improve callus formation. The goal of our study was to review biomechanical data evaluating FCL plate and screw fixation versus standard locking (SL) plate and screw fixation by analyzing studies of cadaveric and synthetic bone models to draw biomechanical conclusions.
Biomechanical studies that compared FCL and SL plate fixation for simulated femoral fractures were reviewed for construct stiffness, load to failure, axial motion at the near and far cortices, and the difference between near and far cortical axial motion to demonstrate motion symmetry.
FCL decreased stiffness by 1.069 kN/mm compared to SL (95 % CI 0.405 to 1.732, p = 0.002). FCL demonstrated greater axial motion than SL in the near cortex by 0.425 mm (95 % CI 0.359 to 0.491, p < 0.001) and in the far cortex by 0.456 mm (95 % CI 0.378 to 0.534, p < 0.001). FCL resulted in symmetric motion with no significant difference between far and near cortices with the far cortex displacing 0.347 mm more than near (95 % CI -0.038 to 0.731, p = 0.78). SL resulted in asymmetric motion favoring the far cortex by 0.270 mm (0.096-0.443, p = 0.002). Construct strength was not significantly different with FCL load to failure 0.367 kN greater than SL (95 % CI -0.762 to 1.496, p = 0.524).
FCL screw fixation in femoral fractures achieves the goals of reducing construct stiffness and promoting more symmetric axial motion while maintaining construct strength. These results support the overall biomechanical goals of far cortical locking and should encourage investigation into its effects on clinical and radiographic outcomes.
远皮质锁定（FCL）是一种锁定钢板固定概念，其刚度降低且微动对称，以促进骨痂形成。我们研究的目的是通过分析尸体和合成骨模型的研究来回顾评估FCL钢板和螺钉固定与标准锁定（SL）钢板和螺钉固定的生物力学数据，从而得出生物力学结论。
对比较FCL和SL钢板固定模拟股骨骨折的生物力学研究进行回顾，分析其结构刚度、破坏载荷、近远皮质的轴向运动以及近远皮质轴向运动的差异，以证明运动对称性。
与SL相比，FCL使刚度降低了1.069kN/mm（95%CI 0.405至1.732，p = 0.002）。FCL在近皮质的轴向运动比SL大0.425mm（95%CI 0.359至0.491，p < 0.001），在远皮质大0.456mm（95%CI 0.378至0.534，p < 0.001）。FCL导致运动对称，远皮质比近皮质多移位0.347mm，差异无统计学意义（95%CI -0.038至0.731，p = 0.78）。SL导致运动不对称，远皮质比近皮质多移位0.270mm（0.096 - 0.443，p = 0.002）。FCL的破坏载荷比SL大0.367kN，但结构强度差异无统计学意义（95%CI -0.762至1.496，p = 0.524）。
股骨骨折的FCL螺钉固定实现了降低结构刚度和促进更对称轴向运动的目标，同时保持了结构强度。这些结果支持远皮质锁定的总体生物力学目标，并应鼓励对其对临床和影像学结果的影响进行研究。
