Department of Orthopaedics & Rehabilitation, Penn State Health, Milton S. Hershey Medical Center, Hershey, PA, USA.
Department of Orthopaedics & Rehabilitation, Penn State Health, Milton S. Hershey Medical Center, Hershey, PA, USA.
Foot Ankle Surg. 2024 Dec;30(8):656-661. doi: 10.1016/j.fas.2024.05.011. Epub 2024 May 24.
The objective of this study was to evaluate the biomechanical stability of a medially placed nitinol staple compared to two crossed-screws in the first TMT-1 joint fusion in a cadaveric cyclic loading model.
Seven matched pairs (N = 7) of lower limb cadaveric specimens were utilized. TMT-1 joints from each donor were fixed with a medially placed nitinol staple or dorsally placed two 3.5 mm partially threaded cannulated crossed-screws. Specimens were tested in a 4-point bending setting with increasing cyclic forces.
The mean plantar gapping was not significantly different between the two groups at any loading stage below 200 N. Specimens fixed with a nitinol staple failed at a mean load of 305 ± 57 N. Conversely, those fixed with crossed-screws failed at 373 ± 86 N. (P = .09).
There was no statistical difference between a medially placed nitinol staple and dorsally placed crossed-screws in failure loads and plantar gapping under cyclic loads at the TMT-1 joint, however, the staple fixation was much more variable.
Level V, basic science study, biomechanics.
本研究旨在评估在尸体循环加载模型中，与 TMT-1 关节融合的两种交叉螺钉相比，内侧放置的镍钛诺钉的生物力学稳定性。
本研究使用了 7 对（N=7）匹配的下肢尸体标本。每个供体的 TMT-1 关节分别用内侧放置的镍钛诺钉或背侧放置的两个 3.5mm 部分螺纹的套管交叉螺钉固定。标本在四点弯曲设置中进行测试，施加递增的循环力。
在低于 200N 的任何加载阶段，两组之间的足底间隙平均值均无显著差异。用镍钛诺钉固定的标本的平均失效负荷为 305±57N。相比之下，用交叉螺钉固定的标本的失效负荷为 373±86N（P=0.09）。
在 TMT-1 关节的循环负荷下，内侧放置的镍钛诺钉与背侧放置的交叉螺钉在失效负荷和足底间隙方面没有统计学差异，但钉固定的变异性更大。
V 级，基础科学研究，生物力学。
