Drewniak Elizabeth I, Jay Gregory D, Fleming Braden C, Crisco Joseph J
Department of Orthopaedics, Bioengineering Laboratory, The Warren Alpert Medical School of Brown University/RIH, Providence, RI, USA.
J Biomech. 2009 Aug 25;42(12):1996-9. doi: 10.1016/j.jbiomech.2009.05.024. Epub 2009 Jul 25.
In attempts to better understand the etiology of osteoarthritis, a debilitating joint disease that results in the degeneration of articular cartilage (AC) in synovial joints, researchers have focused on joint tribology, the study of joint friction, lubrication, and wear. Several different approaches have been used to investigate the frictional properties of articular cartilage. In this study, we examined two analysis methods for calculating the coefficient of friction (micro) using a simple pendulum system and BL6 murine knee joints (n=10) as the fulcrum. A Stanton linear decay model (Lin micro) and an exponential model that accounts for viscous damping (Exp micro) were fit to the decaying pendulum oscillations. Root mean square error (RMSE), asymptotic standard error (ASE), and coefficient of variation (CV) were calculated to evaluate the fit and measurement precision of each model. This investigation demonstrated that while Lin micro was more repeatable, based on CV (5.0% for Lin micro; 18% for Exp micro), Exp micro provided a better fitting model, based on RMSE (0.165 degrees for Exp micro; 0.391 degrees for Lin micro) and ASE (0.033 for Exp micro; 0.185 for Lin micro), and had a significantly lower coefficient of friction value (0.022+/-0.007 for Exp micro; 0.042+/-0.016 for Lin micro) (p=0.001). This study details the use of a simple pendulum for examining cartilage properties in situ that will have applications investigating cartilage mechanics in a variety of species. The Exp mu model provided a more accurate fit to the experimental data for predicting the frictional properties of intact joints in pendulum systems.
为了更好地理解骨关节炎的病因，这是一种导致滑膜关节中关节软骨（AC）退化的使人衰弱的关节疾病，研究人员将重点放在了关节摩擦学上，即对关节摩擦、润滑和磨损的研究。已经使用了几种不同的方法来研究关节软骨的摩擦特性。在本研究中，我们使用一个简单的摆锤系统和BL6小鼠膝关节（n = 10）作为支点，研究了两种计算摩擦系数（μ）的分析方法。将斯坦顿线性衰减模型（Lin μ）和一个考虑粘性阻尼的指数模型（Exp μ）拟合到摆锤的衰减振荡中。计算均方根误差（RMSE）、渐近标准误差（ASE）和变异系数（CV），以评估每个模型的拟合度和测量精度。这项研究表明，虽然基于CV（Lin μ为5.0%；Exp μ为18%），Lin μ更具可重复性，但基于RMSE（Exp μ为0.165度；Lin μ为0.391度）和ASE（Exp μ为0.033；Lin μ为0.185），Exp μ提供了一个更好的拟合模型，并且其摩擦系数值显著更低（Exp μ为0.022±0.007；Lin μ为0.042±0.016）（p = 0.001）。本研究详细介绍了使用简单摆锤原位检查软骨特性的方法，该方法将应用于研究各种物种的软骨力学。Exp μ模型为预测摆锤系统中完整关节的摩擦特性的实验数据提供了更准确的拟合。
