New York-Presbyterian Lower Manhattan Hospital, New York, NY 10038, USA.
AO Research Institute Davos, 7270 Davos, Switzerland.
Medicina (Kaunas). 2023 Jul 15;59(7):1310. doi: 10.3390/medicina59071310.
: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit of simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations in comparison to crossed screws and locked plating in a human anatomical model. : Thirty-two paired human anatomical lower legs were randomized to four groups for TMT-1 treatment via: (1) crossed-screws fixation with two 4.0 mm fully threaded lag screws; (2) plate-and-screw fixation with a 4.0 mm standard fully threaded cortex screw, inserted axially in lag fashion, and a 6-hole TMT-1 Variable-Angle (VA) Fusion Plate 2.4/2.7; (3) CCI fixation with two two-leg staples placed orthogonally to each other; (4) CCI fixation with one two-leg staple and one four-leg staple placed orthogonally to each other. Each specimen was biomechanically tested simulating forefoot weightbearing on the toes and metatarsals. The testing was performed at 35-37 °C under progressively increasing cyclic axial loading until construct failure, accompanied by motion tracking capturing movements in the joints. : Combined adduction and dorsiflexion movement of the TMT-1 joint in unloaded foot condition was associated with no significant differences among all pairs of groups ( ≥ 0.128). In contrast, the amplitude of this movement between unloaded and loaded foot conditions within each cycle was significantly bigger for the two CCI fixation techniques compared to both crossed-screws and plate-and-screw techniques ( ≤ 0.041). No significant differences were detected between the two CCI fixation techniques, as well as between the crossed-screws and plate-and-screw techniques ( ≥ 0.493) for this parameter of interest. Furthermore, displacements at the dorsal and plantar aspects of the TMT-1 joint in unloaded foot condition, together with their amplitudes, did not differ significantly among all pairs of groups ( ≥ 0.224). : The low-profile superelastic nitinol staples demonstrate comparable biomechanical performance to established crossed-screws and plate-and-screw techniques applied for fusion of the first tarsometatarsal joint.
: 本研究旨在探讨在动态负载下，模拟的第一跖跗关节（TMT-1）融合中，使用低轮廓超弹性镍钛诺钉作为连续压缩植入物（CCI）的潜在生物力学优势，与交叉螺钉和锁定板在人体解剖模型中的两种不同配置进行比较。 : 32 对配对的人类解剖学小腿随机分为四组，通过以下方式进行 TMT-1 治疗：（1）交叉螺钉固定，使用两个 4.0 毫米全螺纹拉力螺钉；（2）板钉固定，使用轴向插入的 4.0 毫米标准全螺纹皮质螺钉和 6 孔 TMT-1 可变角度（VA）融合板 2.4/2.7；（3）CCI 固定，使用两个相互正交放置的两腿钉；（4）CCI 固定，使用一个两腿钉和一个四腿钉相互正交放置。每个标本在模拟前足负重于脚趾和跖骨的情况下进行生物力学测试。测试在 35-37°C 下进行，逐步增加循环轴向载荷，直到结构失效，同时进行运动跟踪以捕捉关节的运动。 : 在未加载脚条件下，TMT-1 关节的内收和背屈运动的组合在所有组对之间没有显著差异（≥0.128）。相比之下，在每个循环中，与交叉螺钉和板钉技术相比，两种 CCI 固定技术的未加载脚和加载脚条件之间的这种运动幅度要大得多（≤0.041）。对于感兴趣的这个参数，在两种 CCI 固定技术之间以及在交叉螺钉和板钉技术之间没有检测到显著差异（≥0.493）。此外，在未加载脚条件下，TMT-1 关节的背侧和跖侧的位移以及它们的幅度在所有组对之间没有显著差异（≥0.224）。 : 低轮廓超弹性镍钛诺钉的生物力学性能与应用于第一跖跗关节融合的交叉螺钉和板钉技术相当。
