Lorenz Stephan, Ahrens Philipp, Kirchhoff Sonja, Wolf Petra, Hinterwimmer Stefan, Obermeier Andreas, Beirer Marc, Kirchhoff Chlodwig
Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaningerstrasse 22, 81675, Munich, Germany.
Int Orthop. 2015 May;39(5):865-70. doi: 10.1007/s00264-014-2537-1. Epub 2014 Oct 8.
Anterior cruciate ligament (ACL) injury represents one of the most common diagnoses in orthopaedic sports medicine. In the past, anatomic knowledge about the different bundles within the cruciate ligaments triggered new treatment concepts, such as double-bundle ACL reconstruction. Recently, besides complete tearing, partial ACL ruptures and bundle augmentation became a focus. However, only little is known regarding rotational stability of the knee with an isolated torn postero-lateral (PL) bundle. Therefore, the aim of the present study was the torsiometric analysis of tibio-femoral restraint patterns of the PL-insufficient knee joint.
Fresh human whole body cadavers were enrolled. After diagnostic arthroscopy to ensure the structural integrity of the cruciate ligaments, knee joints underwent torsiometry at 0°, 30°, and 90° degree flexion. Then stepwise the PL bundle and the anteromedial (AM) bundle were arthroscopically resected, while torsiometry of the PL- as well as of the ACL-deficient knee joints was repeated. An area under the curve (AUC) was calculated. All statistical analyses were conducted using a p-value of 0.05 as level of significance.
The comparison of charged and equilibrated curves during internal rotation revealed significant results at low flexion (30° flexion) angles between the ACL intact versus PL absent conditions (p = 0.04). In addition, charged and equilibrated curves during external rotation at 90° flexion, thus high angles, resulted in a significant difference when comparing the ACL-intact with the PL-deficient condition (p = 0.01).
In the present cadaver study using the Torsiometer tool we found a distinct destabilization of the rotational restraints in full knee extension only after total ACL resection. In contrast, no significant findings resulted after an isolated dissection of the PL bundle during internal deflection. Nevertheless, a significant loss of stability was found during unstressed external deflection after isolated PL bundle dissection. Therefore patients, undergoing PL augmentation might benefit regarding rotational instability patterns.
前交叉韧带（ACL）损伤是骨科运动医学中最常见的诊断之一。过去，关于交叉韧带内不同束的解剖学知识引发了新的治疗理念，如双束ACL重建。最近，除了完全撕裂外，部分ACL断裂和束增强成为了焦点。然而，对于单纯后外侧（PL）束撕裂的膝关节旋转稳定性了解甚少。因此，本研究的目的是对PL束功能不全膝关节的胫股约束模式进行扭力分析。
纳入新鲜人体尸体。在进行诊断性关节镜检查以确保交叉韧带的结构完整性后，膝关节在0°、30°和90°屈曲位进行扭力测量。然后逐步通过关节镜切除PL束和前内侧（AM）束，同时重复对PL束功能不全以及ACL缺失膝关节进行扭力测量。计算曲线下面积（AUC）。所有统计分析均以p值0.05作为显著性水平。
内旋过程中加载曲线与平衡曲线的比较显示，在低屈曲（30°屈曲）角度下，ACL完整与PL缺失情况之间有显著差异（p = 0.04）。此外，在90°屈曲（即高角度）的外旋过程中，加载曲线与平衡曲线在比较ACL完整与PL功能不全情况时产生了显著差异（p = 0.01）。
在本使用扭力计工具的尸体研究中，我们发现仅在完全切除ACL后，全膝关节伸直时旋转约束存在明显不稳定。相比之下，在内侧偏斜过程中单独解剖PL束后未发现显著结果。然而，在单独解剖PL束后，无应力外侧偏斜过程中发现稳定性显著丧失。因此，接受PL增强手术的患者可能会从旋转不稳定模式方面获益。
