Department of Mechanical and Materials Engineering, Western University, London, ON, Canada.
Fowler Kennedy Sport Medicine Clinic, Western University, London, ON, Canada.
Knee Surg Sports Traumatol Arthrosc. 2021 Dec;29(12):4172-4181. doi: 10.1007/s00167-021-06483-1. Epub 2021 Mar 7.
Various reconstruction techniques have been employed to restore normal kinematics to PCL-deficient knees; however, studies show that failure rates are still high. Damage to secondary ligamentous stabilizers of the joint, which commonly occurs concurrently with PCL injuries, may contribute to these failures. The main objective of this study was to quantify the biomechanical contributions of the deep medial collateral ligament (dMCL) and posterior oblique ligament (POL) in stabilizing the PCL-deficient knee, using a joint motion simulator.
Eight cadaveric knees underwent biomechanical analysis of posteromedial stability and rotatory laxity using an AMTI VIVO joint motion simulator. Combined posterior force (100 N) and internal torque (5 Nm) loads, followed by pure internal/external torques (± 5 Nm), were applied at 0, 30, 60 and 90° of flexion. The specimens were tested in the intact state, followed by sequential sectioning of the PCL, dMCL, POL and sMCL. The order of sectioning of the dMCL and POL was randomized, providing n = 4 for each cutting sequence. Changes in posteromedial displacements and rotatory laxities were measured, as were the biomechanical contributions of the dMCL, POL and sMCL in resisting these loads in a PCL-deficient knee.
Overall, it was observed that POL transection caused increased posteromedial displacements and internal rotations in extension, whereas dMCL transection had less of an effect in extension and more of an effect in flexion. Although statistically significant differences were identified during most loading scenarios, the increases in posteromedial displacements and rotatory laxity due to transection of the POL or dMCL were usually small. However, when internal torque was applied to the PCL-deficient knee, the combined torque contributions of the dMCL and POL towards resisting rotation was similar to that of the sMCL.
The dMCL and POL are both important secondary stabilizers to posteromedial translation in the PCL-deficient knee, with alternating roles depending on flexion angle. Thus, in a PCL-deficient knee, concomitant injuries to either the POL or dMCL should be addressed with the aim of reducing the risk of PCL reconstruction failure.
为了使 PCL 缺失的膝关节恢复正常运动学，已经采用了各种重建技术；然而，研究表明失败率仍然很高。与 PCL 损伤同时发生的关节次要韧带稳定结构的损伤可能是导致这些失败的原因之一。本研究的主要目的是使用关节运动模拟器量化深内侧副韧带（dMCL）和后斜韧带（POL）在稳定 PCL 缺失膝关节中的生物力学贡献。
8 个尸体膝关节在 AMTI VIVO 关节运动模拟器上进行后内侧稳定性和旋转松弛度的生物力学分析。在 0°、30°、60°和 90°屈曲时，施加 100N 的后向力（100N）和 5Nm 的内扭矩（5Nm），随后施加纯内/外扭矩（±5Nm）。标本在完整状态下进行测试，然后依次切断 PCL、dMCL、POL 和 sMCL。dMCL 和 POL 的切断顺序是随机的，因此在每种切断顺序下 n=4。测量后内侧位移和旋转松弛度的变化，以及 dMCL、POL 和 sMCL 在抵抗 PCL 缺失膝关节中这些载荷的生物力学贡献。
总的来说，观察到 POL 切断导致伸展时后内侧位移和内旋增加，而 dMCL 切断在伸展时影响较小，在屈曲时影响较大。虽然在大多数加载情况下都发现了统计学上的显著差异，但 POL 或 dMCL 切断引起的后内侧位移和旋转松弛度的增加通常很小。然而，当向 PCL 缺失的膝关节施加内扭矩时，dMCL 和 POL 的组合扭矩贡献抵抗旋转与 sMCL 相似。
dMCL 和 POL 都是 PCL 缺失膝关节后内侧平移的重要次要稳定结构，其作用取决于屈曲角度。因此，在 PCL 缺失的膝关节中，POL 或 dMCL 的伴随损伤应得到处理，以降低 PCL 重建失败的风险。
