Medical College, Soochow University, Suzhou, China.
Department of Hand Surgery, Wuxi 9th People's Hospital Affiliated to Soochow University, Wuxi, Jiangsu, China.
Arch Orthop Trauma Surg. 2022 Aug;142(8):2111-2120. doi: 10.1007/s00402-022-04432-2. Epub 2022 Apr 10.
In the reconstruction of distal radioulnar ligaments (DRULs), interference screws can be used for antegrade or retrograde fixation of grafts to the ulna. However, the biomechanics of interference screw fixation are currently unknown. This study aimed to determine the biomechanical effects of these two fixations on the distal radioulnar joint (DRUJ) in a cadaveric model and to investigate the appropriate initial tension.
A total of 30 human cadaver upper extremities were used, and the DRULs were reconstructed according to Adams' procedure. First, eight specimens were randomly divided into two groups: antegrade and retrograde, followed by translational testing and load testing. Then, the other eight specimens were divided into the two groups above, and the contact mechanics, including forces, areas, and pressures, were measured. Finally, to investigate the appropriate initial tension, the remaining 14 specimens were fixed with interference screws under different tensions in an antegrade way, and the translational testing was repeated as before.
In the neutral position, antegrade fixation exhibited less translation than retrograde fixation (7.21 ± 0.17 mm versus 10.77 ± 1.68 mm, respectively). The maximum failure load was 70.45 ± 6.20 N in antegrade fixation, while that in retrograde fixation was 35.17 ± 2.95 N (P < 0.0001). Antegrade fixation exhibited a larger increase in contact force than retrograde fixation (99.72% ± 23.88% versus 28.18% ± 10.43%) (P = 0.001). The relationship between tension and displacement was nonlinear (Y = - 1.877 ln(x) + 7.94, R = 0.868, P < 0.0001).
Compared with retrograde fixation, the antegrade fixation of interference screws may be a more reliable surgical technique, as it shows a higher failure load and stability. In addition, to avoid the risk of potential arthritis caused by anterograde fixation, we propose an equation to determine the appropriate initial tension in DRUL reconstruction.
在重建桡尺远侧韧带（DRUL）时，可使用干涉螺钉从前向或后向将移植物固定到尺骨。然而，目前尚不清楚干涉螺钉固定的生物力学。本研究旨在确定在尸体模型中这两种固定方式对桡尺远侧关节（DRUJ）的生物力学影响，并探讨合适的初始张力。
共使用 30 个人体上肢标本，根据 Adams 手术重建 DRUL。首先，将 8 个标本随机分为两组：前向和后向，然后进行平移测试和负载测试。然后，将另外 8 个标本分为上述两组，并测量接触力学，包括力、面积和压力。最后，为了探讨合适的初始张力，采用前向方式在 14 个不同张力下用干涉螺钉固定，然后重复进行平移测试。
在中立位时，前向固定的平移距离小于后向固定（分别为 7.21 ± 0.17mm 和 10.77 ± 1.68mm）。前向固定的最大失效负荷为 70.45 ± 6.20N，而后向固定的最大失效负荷为 35.17 ± 2.95N（P < 0.0001）。前向固定的接触力增加幅度大于后向固定（99.72% ± 23.88%比 28.18% ± 10.43%）（P = 0.001）。张力与位移的关系是非线性的（Y = -1.877ln（x）+7.94，R = 0.868，P < 0.0001）。
与后向固定相比，前向固定干涉螺钉可能是一种更可靠的手术技术，因为它显示出更高的失效负荷和稳定性。此外，为了避免前向固定引起潜在关节炎的风险，我们提出了一个确定 DRUL 重建中合适初始张力的方程。
