Van Nguyen Luong
Institute of Trauma and Orthopaedics, 108 Central Military Hospital, No. 01 Tran Hung Dao Street, Hanoi, Vietnam.
Eur J Orthop Surg Traumatol. 2024 Feb;34(2):839-846. doi: 10.1007/s00590-023-03726-4. Epub 2023 Sep 23.
The mechanical characteristics of leg lengthening over a nail (LON) using an external fixator are not well known; specifically, the number of rings and K-wires required for this method has not been determined. This study aimed to compare the mechanical characteristics of leg LON using the simplest configuration for a domestic frame and those of leg lengthening using the Ilizarov frame alone.
The mechanical characteristics of cow tibial samples for lengthening over an intramedullary nail in combination with a domestic external fixator (LON samples) and for lengthening with the Ilizarov frame (Ilizarov samples) were evaluated by assessing axial compression, bending load, and torsional load. The research indices were compression stiffness, bending stiffness, torsion stiffness, yield axial load, ultimate axial load, yield bending load, and ultimate bending load.
No statistically significant differences were observed in the compression stiffness, ultimate axial load, bending stiffness, and ultimate, yield bending forces between the Ilizarov samples and LON samples. The compressive stiffness, yield axial load, and ultimate axial load of the LON samples were 98 ± 1.31 N/mm, 915 ± 23.89 N, and 1032 ± 29.86 N, respectively. The anterior-posterior bending stiffness and lateral bending stiffness of the LON samples were 122.48 ± 2.92 N/mm and 116.34 ± 3.95 N/mm, respectively. The yield anterior-posterior bending and ultimate anterior-posterior bending forces of the LON samples were 616.4 ± 3.64 N and 753.2 ± 3.49 N, respectively. The yield lateral bending and ultimate lateral bending forces of the LON samples were 624.6 ± 4.04 N and 759.0 ± 3.39 N, respectively. The axial torsional stiffness of the LON samples was 1.73 ± 0.05 N m/°, which was significantly lower than that of the Ilizarov samples (2.63 ± 0.03 N m/°).
No statistically significant differences were observed in the mechanical fixation characteristics of axial compression and bending between the Ilizarov samples and LON samples. However, the axial torsional stiffness of the Ilizarov samples was statistically greater than that of the LON samples. We recommend using the simplest configuration for domestic frames in combination with LON for limb lengthening. Partial weight-bearing is permitted in the distraction stage.
Case-control study.
使用外固定器在髓内钉上进行肢体延长（LON）的力学特性尚不明确；具体而言，该方法所需的环和克氏针数量尚未确定。本研究旨在比较使用国产框架最简单配置进行肢体LON的力学特性与单独使用伊里扎洛夫框架进行肢体延长的力学特性。
通过评估轴向压缩、弯曲载荷和扭转载荷，对结合国产外固定器在髓内钉上进行延长的牛胫骨样本（LON样本）和使用伊里扎洛夫框架进行延长的牛胫骨样本（伊里扎洛夫样本）的力学特性进行评估。研究指标为压缩刚度、弯曲刚度、扭转刚度、屈服轴向载荷、极限轴向载荷、屈服弯曲载荷和极限弯曲载荷。
伊里扎洛夫样本和LON样本在压缩刚度、极限轴向载荷、弯曲刚度以及极限和屈服弯曲力方面未观察到统计学上的显著差异。LON样本的压缩刚度、屈服轴向载荷和极限轴向载荷分别为98±1.31N/mm、915±23.89N和1032±29.86N。LON样本的前后弯曲刚度和侧向弯曲刚度分别为122.48±2.92N/mm和116.34±3.95N/mm。LON样本的屈服前后弯曲力和极限前后弯曲力分别为616.4±3.64N和753.2±3.49N。LON样本的屈服侧向弯曲力和极限侧向弯曲力分别为624.6±4.04N和759.±3.39N。LON样本的轴向扭转刚度为1.73±0.05N·m/°，显著低于伊里扎洛夫样本（2.63±0.03N·m/°）。
伊里扎洛夫样本和LON样本在轴向压缩和弯曲的机械固定特性方面未观察到统计学上的显著差异。然而，伊里扎洛夫样本的轴向扭转刚度在统计学上大于LON样本。我们建议在肢体延长中使用国产框架的最简单配置结合LON。在牵张期允许部分负重。
病例对照研究。
