Department of Orthopeadics, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, No. 365 Renmin East Road, Jinhua City, 321000, Zhejiang Province, China.
Department of Radiology, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, No. 365 Renmin East Road, Jinhua City, 321000, Zhejiang Province, China.
J Orthop Surg Res. 2022 Mar 28;17(1):185. doi: 10.1186/s13018-022-03034-3.
The posterolateral complex (PLC), which consists of the popliteus tendon (PT), lateral collateral ligament (LCL), and popliteofibular ligament (PFL), is an indispensable structure of the knee joint. The aim of this study was to explore the functionality of the PLC by determining the specific role of each component in maintaining posterolateral knee stability.
A finite element (FE) model was generated based on previous material property data and magnetic resonance imaging of a volunteer's knee joint. The injury order of the PLC was set as LCL, PFL, and PT. A combined compressive load of 1150 N and an anterior tibial load of 134 N was applied to the tibia to investigate tibial displacement (TD). Tibial external rotation (TER) and tibial varus angulation (TVA) were measured under bending motions of 5 and 10 Nm. The instantaneous axis of rotation (IAR) of the knee joint under different rotation motions was also recorded.
The TD of the intact knee under a combined compressive load of 1150 N and an anterior tibial load of 134 N matched the values determined in previous studies. Our model showed consistent increases in TD, TVA, and TER after sequential damage of the PLC. In addition, sequential disruption caused the IAR to shift superiorly and laterally during varus rotation and medially and anteriorly during external rotation. In the dynamic damage of the PLC, LCL injury had the largest effect on TD, TVA, TER, and IAR.
Sequential injury of the PLC caused considerable loss of stability of the knee joint according to an FE model. The most significant structure of the PLC was the LCL.
后外侧复合体（PLC）由腘肌腱（PT）、外侧副韧带（LCL）和腓肠豆股韧带（PFL）组成，是膝关节不可或缺的结构。本研究旨在通过确定每个组成部分在维持膝关节后外侧稳定性方面的特定作用来探索 PLC 的功能。
根据志愿者膝关节的先前材料特性数据和磁共振成像生成有限元（FE）模型。PLC 的损伤顺序设定为 LCL、PFL 和 PT。对胫骨施加 1150N 的组合压缩载荷和 134N 的胫骨前负荷，以研究胫骨位移（TD）。在 5Nm 和 10Nm 的弯曲运动下测量胫骨外旋（TER）和胫骨内翻角度（TVA）。还记录了膝关节在不同旋转运动下的瞬时旋转轴（IAR）。
在 1150N 的组合压缩载荷和 134N 的胫骨前负荷下，完整膝关节的 TD 与先前研究确定的值相匹配。我们的模型显示，PLC 连续损伤后，TD、TVA 和 TER 均呈一致增加。此外，在进行内侧旋转时，IAR 会向上和向外侧移位，而在进行外侧旋转时，IAR 会向内侧和向前移位。在 PLC 的动态损伤中，LCL 损伤对 TD、TVA、TER 和 IAR 的影响最大。
根据 FE 模型，PLC 的连续损伤会导致膝关节稳定性显著丧失。PLC 中最重要的结构是 LCL。
