滑液对关节软骨边界润滑的影响。

Effect of synovial fluid on boundary lubrication of articular cartilage.

作者信息

Schmidt T A, Sah R L

机构信息

Department of Bioengineering and Whitaker Institute of Biomedical Engineering, University of California--San Diego, La Jolla, CA 92093, USA.

出版信息

Osteoarthritis Cartilage. 2007 Jan;15(1):35-47. doi: 10.1016/j.joca.2006.06.005. Epub 2006 Jul 21.

DOI:10.1016/j.joca.2006.06.005

PMID:16859933

Abstract

OBJECTIVES

The lubrication of articulating cartilage surfaces in joints occurs through several distinct modes. In the boundary mode of lubrication, load is supported by surface-to-surface contact, a feature that makes this mode particularly important for maintenance of the normally pristine articular surface. A boundary mode of lubrication is indicated by a kinetic friction coefficient being invariant with factors that influence formation of a fluid film, including sliding velocity and axial load. The objectives of this study were to (1) implement and extend an in vitro articular cartilage-on-cartilage lubrication test to elucidate the dependence of the friction properties on sliding velocity, axial load, and time, and establish conditions where a boundary mode of lubrication is dominant, and (2) determine the effects of synovial fluid (SF) on boundary lubrication using this test.

METHODS

Fresh bovine osteochondral samples were analyzed in an annulus-on-disk rotational configuration, maintaining apposed articular surfaces in contact, to determine static (mu(static) and mu(static),(N(eq)) and kinetic ([mu(kinetic)] and [mu(kinetic),(N(eq))]) friction coefficients, each normalized to the instantaneous and equilibrium (N(eq)) normal loads, respectively.

RESULTS

With increasing pre-sliding durations, mu(static) and mu(static),(N(eq)) were similar, and increased up to 0.43 +/- 0.03 in phosphate buffered saline (PBS) and 0.19 +/- 0.01 in SF, whereas [mu(kinetic)] and [mu(kinetic),(N(eq))] were steady. Over a range of sliding velocities of 0.1-1 mm/s and compression levels of 18% and 24%, [mu(kinetic)] was 0.072 +/- 0.010 in PBS and 0.014 +/- 0.003 in SF, and [mu(kinetic),(N(eq))] was 0.093 +/- 0.005 in PBS and 0.018 +/- 0.002 in SF.

CONCLUSIONS

A boundary mode of lubrication was achieved in a cartilage-on-cartilage test configuration. SF functioned as an effective friction-lowering boundary lubricant for native articular cartilage surfaces.

摘要

目的

关节中关节软骨表面的润滑通过几种不同模式发生。在边界润滑模式下，载荷由表面与表面的接触来支撑，这一特性使得该模式对于维持通常 pristine 的关节表面尤为重要。边界润滑模式由动摩擦系数不随影响流体膜形成的因素（包括滑动速度和轴向载荷）而变化来表明。本研究的目的是：（1）实施并扩展体外软骨对软骨的润滑试验，以阐明摩擦特性对滑动速度、轴向载荷和时间的依赖性，并确定边界润滑模式占主导的条件；（2）使用该试验确定滑液（SF）对边界润滑的影响。

方法

采用环盘旋转配置分析新鲜牛骨软骨样本，保持相对的关节表面接触，以确定静态（μ(static) 和 μ(static),(N(eq))）和动态（[μ(kinetic)] 和 [μ(kinetic),(N(eq))]）摩擦系数，每个系数分别相对于瞬时和平衡（N(eq)）法向载荷进行归一化。

结果

随着预滑动持续时间增加，μ(static) 和 μ(static),(N(eq)) 相似，在磷酸盐缓冲盐水（PBS）中增加至 0.43±0.03，在 SF 中增加至 0.19±0.01，而 [μ(kinetic)] 和 [μ(kinetic),(N(eq))] 保持稳定。在 0.1 - 1 mm/s 的滑动速度范围和 18%及 24%的压缩水平下，[μ(kinetic)] 在 PBS 中为 0.072±0.010，在 SF 中为 0.014±0.003，[μ(kinetic),(N(eq))] 在 PBS 中为 0.093±0.005，在 SF 中为 0.018±0.002。