Abstract：
BACKGROUND: To treat anterior cruciate ligament (ACL) injuries, double-bundle ACL reconstruction has been proposed as a more anatomical approach relative to single-bundle reconstruction. However, controversy remains over which technique is superior in addressing knee instability, particularly rotational laxity. We hypothesize that double-bundle reconstruction better restores rotational knee laxity, while both methods are similar in restoring anterior knee laxity, to intact knee levels.
METHODS: A controlled laboratory study. Eight cadaveric knees were tested accordingly: (1) static anterior laxity testing under 150 N-anterior tibial loading at 20°, 60° and 90° knee flexion using a material testing machine, followed by (2) dynamic simulated pivot-shift with knee-specific loading involving iliotibial band forces, valgus and internal rotation torques, while the knee was brought from extension to 90° flexion on a 6°-of-freedom custom-designed rig. Tibiofemoral kinematics were recorded using an electromagnetic tracking system for the ACL-intact, ACL-deficient, single-bundle and double-bundle ACL-reconstructed knee conditions.
RESULTS: Double-bundle reconstruction reduced internal rotation under pivot-shift to levels not significantly different from ACL-intact conditions (P > .173), unlike single-bundle that remained significantly higher at 10-40° flexion (P < .05). For anterior laxity, there was no significant difference between double-bundle, single-bundle, and ACL-intact conditions under static testing (P > .175) or pivot-shift (P = .219). The maximum extent of knee envelope laxity was significantly reduced for double-bundle relative to single-bundle, particularly for the rotatory component (P = .012).
CONCLUSIONS: Double-bundle was biomechanically superior to single-bundle in addressing envelope of rotation, while both techniques restored anterior knee laxity to ACL-intact levels.
METHODS: A controlled laboratory study. Eight cadaveric knees were tested accordingly: (1) static anterior laxity testing under 150 N-anterior tibial loading at 20°, 60° and 90° knee flexion using a material testing machine, followed by (2) dynamic simulated pivot-shift with knee-specific loading involving iliotibial band forces, valgus and internal rotation torques, while the knee was brought from extension to 90° flexion on a 6°-of-freedom custom-designed rig. Tibiofemoral kinematics were recorded using an electromagnetic tracking system for the ACL-intact, ACL-deficient, single-bundle and double-bundle ACL-reconstructed knee conditions.
RESULTS: Double-bundle reconstruction reduced internal rotation under pivot-shift to levels not significantly different from ACL-intact conditions (P > .173), unlike single-bundle that remained significantly higher at 10-40° flexion (P < .05). For anterior laxity, there was no significant difference between double-bundle, single-bundle, and ACL-intact conditions under static testing (P > .175) or pivot-shift (P = .219). The maximum extent of knee envelope laxity was significantly reduced for double-bundle relative to single-bundle, particularly for the rotatory component (P = .012).
CONCLUSIONS: Double-bundle was biomechanically superior to single-bundle in addressing envelope of rotation, while both techniques restored anterior knee laxity to ACL-intact levels.
摘要：
背景：为了治疗前交叉韧带（ACL）损伤，双束ACL重建已被提出作为相对于单束重建更解剖的方法。然而,关于哪种技术在解决膝盖不稳定方面更优越的争议仍然存在，特别是旋转松弛。我们假设双束重建能更好地恢复旋转膝关节松弛，虽然两种方法在恢复前膝关节松弛方面相似，到完整的膝盖水平。
方法：对照实验室研究。对八个尸体膝盖进行了相应的测试：（1）在150N胫骨前负荷下在20°下进行静态前松弛测试，使用材料试验机进行60°和90°膝关节屈曲，其次是（2）动态模拟的枢轴移位与膝关节特定的负荷，涉及髂胫带力，外翻和内部旋转扭矩，而膝盖在6°自由定制设计的钻机上从伸展到90°弯曲。使用电磁跟踪系统记录了完整的ACL，ACL缺陷，单束和双束ACL重建膝关节条件。
结果：双束重建将枢轴移位下的内部旋转减少到与ACL完整条件没有显着差异的水平（P>.173），与单束在10-40°屈曲时保持显著较高不同（P<.05）。对于前部松弛，双束之间没有显着差异，单束,静态测试(P>.175)或枢轴移位(P=.219)下的ACL-完整条件。双束相对于单束，膝盖包膜松弛的最大程度显着降低，特别是对于旋转组件(P=.012)。
结论：双束在解决旋转包络线方面的生物力学优于单束，而两种技术都恢复了前膝关节松弛至ACL完整水平。
方法：对照实验室研究。对八个尸体膝盖进行了相应的测试：（1）在150N胫骨前负荷下在20°下进行静态前松弛测试，使用材料试验机进行60°和90°膝关节屈曲，其次是（2）动态模拟的枢轴移位与膝关节特定的负荷，涉及髂胫带力，外翻和内部旋转扭矩，而膝盖在6°自由定制设计的钻机上从伸展到90°弯曲。使用电磁跟踪系统记录了完整的ACL，ACL缺陷，单束和双束ACL重建膝关节条件。
结果：双束重建将枢轴移位下的内部旋转减少到与ACL完整条件没有显着差异的水平（P>.173），与单束在10-40°屈曲时保持显著较高不同（P<.05）。对于前部松弛，双束之间没有显着差异，单束,静态测试(P>.175)或枢轴移位(P=.219)下的ACL-完整条件。双束相对于单束，膝盖包膜松弛的最大程度显着降低，特别是对于旋转组件(P=.012)。
结论：双束在解决旋转包络线方面的生物力学优于单束，而两种技术都恢复了前膝关节松弛至ACL完整水平。
