New parameters describing how knee ligaments carry force in situ predict interspecimen variations in laxity during simulated clinical exams
New parameters describing how knee ligaments carry force in situ predict interspecimen variations in laxity during simulated clinical exams
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DOI：
10.1016/j.jbiomech.2017.09.032
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发表时间：
2017-11-07
影响因子：
2.4
通讯作者：
Pearle, Andrew D.
中科院分区：
文献类型：
--
作者：
Imhauser, Carl W.;Kent, Robert N., III;Pearle, Andrew D.
膝关节松弛定义为胫骨相对于股骨在给定方向上响应于所施加的载荷的净平移或旋转，其在人与人之间具有高度可变性。常规临床检查中评估的膝关节高度松弛与重建后首次韧带损伤和移植物再损伤有关。在松弛度检查期间，韧带承载力以抵抗施加的载荷;然而，膝关节松弛度的受试者间变化与膝关节通过其被动运动包络时韧带承载力的变化（我们称之为韧带接合）之间的关系尚未得到很好的建立。因此，本研究的目的首先是定义描述韧带接合的参数，然后将一组膝关节的韧带接合变化和松弛变化联系起来。我们在尸体膝关节模型（n = 20）中使用机器人操纵器来量化膝关节稳定器（即前交叉韧带和后交叉韧带（分别为ACL和PCL）以及内侧副韧带（MCL））在前、后和外翻松弛测试中的重要性。使用三个参数量化韧带接合：（1）原位松弛，定义为从关节中性位置到韧带开始承载力的位置的相对胫股运动;（2）原位刚度，定义为韧带力-胫骨运动响应的线性部分的斜率;和（3）峰值施加载荷时的韧带力。使用单变量和多变量回归模型，膝关节松弛与韧带接合参数相关。ACL和PCL的原位松弛变化预测了前后松弛，而MCL的原位松弛和原位刚度变化预测了外翻松弛。韧带接合参数可用于进一步表征韧带和韧带移植物的原位生物力学功能。(C)2017爱思唯尔有限公司版权所有
Knee laxity, defined as the net translation or rotation of the tibia relative to the femur in a given direction in response to an applied load, is highly variable from person to person. High levels of knee laxity as assessed during routine clinical exams are associated with first-time ligament injury and graft reinjury following reconstruction. During laxity exams, ligaments carry force to resist the applied load; however, relationships between intersubject variations in knee laxity and variations in how ligaments carry force as the knee moves through its passive envelope of motion, which we refer to as ligament engagement, are not well established. Thus, the objectives of this study were, first, to define parameters describing ligament engagement and, then, to link variations in ligament engagement and variations in laxity across a group of knees. We used a robotic manipulator in a cadaveric knee model (n = 20) to quantify how important knee stabilizers, namely the anterior and posterior cruciate ligaments (ACL and PCL, respectively), as well as the medial collateral ligament (MCL) engage during respective tests of anterior, posterior, and valgus laxity. Ligament engagement was quantified using three parameters: (1) in situ slack, defined as the relative tibiofemoral motion from the neutral position of the joint to the position where the ligament began to carry force; (2) in situ stiffness, defined as the slope of the linear portion of the ligament force-tibial motion response; and (3) ligament force at the peak applied load. Knee laxity was related to parameters of ligament engagement using univariate and multivariate regression models. Variations in the in situ slack of the ACL and PCL predicted anterior and posterior laxity, while variations in both in situ slack and in situ stiffness of the MCL predicted valgus laxity. Parameters of ligament engagement may be useful to further characterize the in situ biomechanical function of ligaments and ligament grafts. (C) 2017 Elsevier Ltd. All rights reserved.