Gacek Elizabeth, Ellingson Arin M, Barocas Victor H
Department of Biomedical Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55455.
Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota - Twin Cities, Minneapolis, MN 55455.
J Biomech Eng. 2024 Nov 1;146(11). doi: 10.1115/1.4066091.
Modeling the lumbar facet capsular ligament's (FCL) mechanical behavior under various physiological motions has often been a challenge due to limited knowledge about the on-joint in situ ligament state arising from attachment to the bone or other internal loads. Building on prior work, this study presents an enhanced computational model of the lumbar facet capsular ligament by incorporating residual strain and joint pressurization strain, factors neglected in prior models. Further, the model can predict strain and stress distribution across the ligament under various spinal motions, highlighting the influence of the ligament's attachment to the bone, internal synovial fluid pressurization, and distribution of collagen fiber alignment on the overall mechanical response of the ligament. Joint space inflation was found to influence the total observed stress and strain fields, both at rest and during motion. A significant portion of the ligament was found to be in tension, even in the absence of external load. Additionally, the model's ability to account for residual strain offers a more realistic portrayal of the collagen fibers and elastin matrix's role in ligament mechanics. We conclude that (1) computational models of the lumbar facet capsular ligament should not assume that the ligament is unloaded when the joint is in its neutral position, and (2) the ligament is nearly always in tension, which may be important in terms of its long-term growth and remodeling.
由于对附着于骨骼或其他内部负荷所产生的关节内原位韧带状态了解有限，模拟腰椎小关节囊韧带（FCL）在各种生理运动下的力学行为一直是一项挑战。基于先前的工作，本研究通过纳入残余应变和关节加压应变（先前模型中忽略的因素），提出了一种增强的腰椎小关节囊韧带计算模型。此外，该模型可以预测在各种脊柱运动下韧带的应变和应力分布，突出了韧带与骨骼的附着、内部滑液加压以及胶原纤维排列分布对韧带整体力学响应的影响。发现关节间隙膨胀会影响静止和运动时观察到的总应力和应变场。即使在没有外部负荷的情况下，也发现韧带的很大一部分处于拉伸状态。此外，该模型考虑残余应变的能力更真实地描绘了胶原纤维和弹性蛋白基质在韧带力学中的作用。我们得出结论：（1）腰椎小关节囊韧带的计算模型不应假设关节处于中立位置时韧带无负荷，（2）韧带几乎总是处于拉伸状态，这在其长期生长和重塑方面可能很重要。
