Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Arthroscopy. 2012 Feb;28(2):247-54. doi: 10.1016/j.arthro.2011.07.019. Epub 2011 Oct 21.
To investigate the biomechanics of the intermediate (IM), anteromedial (AM), and posterolateral (PL) bundles in the human anterior cruciate ligament (ACL).
Eighteen human cadaveric knees were tested with a robotic/universal force-moment sensor testing system. Anterior tibial translation (ATT) was determined under an 89-N anterior tibial load. Coupled ATT was determined under a combined rotatory load of 7-Nm valgus and 5-Nm internal rotation torque (pivot moment). Each bundle's in situ forces were measured under identical external loading conditions.
Under anterior load, the PL bundle's in situ force was highest at 0° and decreased during flexion. Under the anterior load, the AM bundle's in situ force was significantly higher than the IM and PL bundles' force at 15°, 30°, and 60°. Under the pivot moment, the AM bundle's in situ force was significantly higher than the PL and IM bundles' force at 0° and 15°, and the IM bundle had the lowest in situ force at 0° but higher in situ force than the AM and PL bundles at 30° and 45°. IM and AM bundle removal increased ATT under the anterior load at all angles. Cutting the PL bundle after IM and AM bundle removal (whole ACL removal) significantly increased ATT under the anterior load at 0°, 15°, and 30° of knee flexion and increased coupled ATT under the pivot moment at 0° and 15°.
The biomechanical role of each of the 3 ACL bundles (AM, IM, and PL) was measured with a robotic/universal force-moment sensor testing system. The AM bundle stabilized the knee against both the anterior and rotatory loads. The PL bundle stabilized the knee especially near full extension. The IM bundle supported the AM and PL bundles through all flexion angles, especially from 30° to 45°, against the rotatory load.
Knowledge of functions of the different ACL bundles will help improve ACL reconstruction techniques to enable restoration of normal knee function.
研究人体前交叉韧带（ACL）中间束（IM）、前内侧束（AM）和后外侧束（PL）的生物力学特性。
18 个人体尸体膝关节采用机器人/通用力-力矩传感器测试系统进行测试。在 89N 的胫骨前负荷下确定胫骨前平移（ATT）。在 7Nm 外翻和 5Nm 内旋扭矩（枢轴力矩）的复合旋转负荷下确定耦合 ATT。在相同的外部加载条件下测量每个束的原位力。
在前负荷下，PL 束的原位力在 0°时最高，并在屈曲过程中降低。在前负荷下，AM 束的原位力在 15°、30°和 60°时明显高于 IM 和 PL 束的力。在枢轴力矩下，AM 束的原位力在 0°和 15°时明显高于 PL 和 IM 束的力，而 IM 束在 0°时的原位力最低，但在 30°和 45°时的原位力高于 AM 和 PL 束。在前负荷下，在所有角度，切除 IM 和 AM 束后增加 ATT。在 IM 和 AM 束切除后（ACL 完全切除），切除 PL 束可显著增加前负荷下 0°、15°和 30°的 ATT，以及枢轴力矩下 0°和 15°的耦合 ATT。
使用机器人/通用力-力矩传感器测试系统测量了 3 个 ACL 束（AM、IM 和 PL）的生物力学作用。AM 束稳定膝关节抵抗前向和旋转负荷。PL 束尤其在完全伸展时稳定膝关节。IM 束通过所有屈曲角度支撑 AM 和 PL 束，尤其是在 30°到 45°之间，抵抗旋转负荷。
了解不同 ACL 束的功能将有助于改进 ACL 重建技术，以恢复正常的膝关节功能。
