Johnson Jared S, Smith Sean D, LaPrade Christopher M, Turnbull Travis Lee, LaPrade Robert F, Wijdicks Coen A
Steadman Philippon Research Institute, Vail, Colorado, USA The Steadman Clinic, Vail, Colorado, USA.
Steadman Philippon Research Institute, Vail, Colorado, USA.
Am J Sports Med. 2015 Jan;43(1):154-60. doi: 10.1177/0363546514553779. Epub 2014 Oct 17.
Graft healing after soft tissue anterior cruciate ligament (ACL) reconstruction requires rigid fixation to allow for soft tissue healing. Cortical suspension devices for femoral fixation should be biomechanically tested under high loads representative of early rehabilitation to evaluate whether they provide sufficient fixation.
PURPOSE/HYPOTHESIS: To biomechanically compare current fixed-loop and adjustable-loop cortical suspension devices for soft tissue femoral fixation under high loads. The hypotheses were that there would be significant differences in cyclic displacement between devices, independent of loop type, and that retensioning of the adjustable-loop devices would not significantly alter the biomechanical properties of these devices.
Controlled laboratory study.
Five different femoral ACL graft cortical suspension devices (3 fixed and 2 adjustable) were compared under high cyclic forces (100-400 N for 1000 cycles) and then pulled to failure at 50 mm/min. In addition, the effect of retensioning after simulated preconditioning was evaluated for the 2 adjustable-loop devices.
On average, the least amount of cumulative peak cyclic displacement (mean±SD) was observed for the ENDOBUTTON (1.05±0.05 mm), followed by the RIGIDLOOP (1.09±0.16 mm), XO Button (1.65±0.43 mm), TightRope with retensioning (1.81±0.51 mm), TightRope without retensioning (2.20±0.62 mm), ToggleLoc with retensioning (3.22±1.41 mm), and ToggleLoc without retensioning (3.69±2.39 mm). The ENDOBUTTON displaced significantly less after cyclic loading than all adjustable-loop devices (TightRope and ToggleLoc, both with and without retensioning) and the XO Button. The RIGIDLOOP displaced significantly less than the TightRope without retensioning and ToggleLoc with and without retensioning. There was no significant difference in biomechanical properties after retensioning for both adjustable-loop devices.
Significant differences were observed between current fixed-loop and adjustable-loop cortical suspension devices for soft tissue femoral fixation when subjected to high loads experienced during rehabilitation. Retensioning did not significantly alter the biomechanical properties of adjustable-loop devices.
Early rehabilitation protocols subject the graft construct to higher forces than what has been previously tested biomechanically. Biomechanical testing of cortical suspension devices under simulated high rehabilitation loads demonstrated significant differences between devices. Future studies should investigate the clinical implications of these time zero results.
前交叉韧带（ACL）重建术后软组织移植物的愈合需要牢固固定，以促进软组织愈合。用于股骨固定的皮质悬吊装置应在代表早期康复的高负荷下进行生物力学测试，以评估其是否能提供足够的固定。
目的/假设：在高负荷下对当前用于软组织股骨固定的固定环和可调环皮质悬吊装置进行生物力学比较。假设是不同装置之间在循环位移上会有显著差异，与环的类型无关，并且可调环装置的重新张紧不会显著改变这些装置的生物力学性能。
对照实验室研究。
在高循环力（100 - 400 N，循环1000次）下比较五种不同的股骨ACL移植物皮质悬吊装置（3种固定型和2种可调型），然后以50 mm/min的速度拉至失效。此外，对2种可调环装置评估了模拟预处理后重新张紧的效果。
平均而言，ENDOBUTTON观察到的累积峰值循环位移量最少（均值±标准差，1.05±0.05 mm），其次是RIGIDLOOP（1.09±0.16 mm）、XO Button（1.65±0.43 mm）、重新张紧的TightRope（1.81±0.51 mm）、未重新张紧的TightRope（2.20±0.62 mm）、重新张紧的ToggleLoc（3.22±1.41 mm）和未重新张紧的ToggleLoc（3.69±2.39 mm）。循环加载后，ENDOBUTTON的位移明显小于所有可调环装置（TightRope和ToggleLoc，无论是否重新张紧）以及XO Button。RIGIDLOOP的位移明显小于未重新张紧的TightRope以及重新张紧和未重新张紧的ToggleLoc。两种可调环装置重新张紧后的生物力学性能没有显著差异。
在康复过程中承受的高负荷下，当前用于软组织股骨固定的固定环和可调环皮质悬吊装置之间观察到显著差异。重新张紧没有显著改变可调环装置的生物力学性能。
早期康复方案使移植物承受比先前生物力学测试更高的力。在模拟高康复负荷下对皮质悬吊装置进行生物力学测试表明不同装置之间存在显著差异。未来研究应调查这些零时结果的临床意义。
