BACKGROUND Osteoarthritis is a common, localized joint disease that causes pain, stiffness and reduced mobility. Osteoarthritis is particularly common in the knees. The effects of osteoarthritis on the rheology of synovial fluid in the knees are not fully understood and consequently require further study. OBJECTIVE The purpose of this study is to investigate the effects of protein content on synovial fluid shear rheology. A secondary study outcome will include study of the temperature dependence of synovial fluid behaviour. METHODS 38 osteoarthritic synovial fluid samples were studied under shear flow. Shear properties were correlated with protein concentration. Viscosupplement was used as a comparison and to verify measurement reliability. The effects of temperature were investigated at 20, 29 and 37°C. RESULTS Shear rheological properties were found to vary widely between samples, however all samples demonstrated clear non-Newtonian shear thinning behaviour. In general viscoelastic properties were lower in osteoarthritic samples than previously studied healthy synovial fluid. A moderate correlation was observed between synovial fluid dynamic moduli at a frequency of 2.5 Hz and protein concentration. Temperature was found to affect the rheology of osteoarthritic synovial fluid and was fitted with the Arrhenius model. CONCLUSIONS Increased protein concentration has been correlated with decreased shear rheological parameters. Temperature dependence of synovial fluid was also demonstrated and modelled for use in Part 2 of this article.

中文翻译：

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骨关节炎滑液的流变性及其与蛋白质浓度的关系。

背景技术骨关节炎是一种常见的局部关节疾病，其引起疼痛，僵硬和活动能力降低。骨关节炎在膝盖中尤为常见。骨关节炎对膝关节滑液流变性的影响尚未完全了解，因此需要进一步研究。目的本研究的目的是研究蛋白质含量对滑液剪切流变学的影响。次要研究结果将包括对滑液行为的温度依赖性的研究。方法对38例骨关节炎滑液进行剪切流研究。剪切特性与蛋白质浓度相关。粘稠度用作比较并验证测量的可靠性。在20、29和37°C下研究了温度的影响。结果发现样品之间的剪切流变性质差异很大，但是所有样品均表现出明显的非牛顿剪切稀化行为。通常，骨关节炎样品的粘弹性比以前研究的健康滑液低。在频率为2.5 Hz的滑液动态模量与蛋白质浓度之间观察到适度的相关性。发现温度会影响骨关节炎滑液的流变性，并符合Arrhenius模型。结论增加的蛋白质浓度与降低的剪切流变学参数有关。还证明了滑液的温度依赖性，并对其进行了建模，以用于本文的第2部分。但是，所有样品均表现出明显的非牛顿剪切稀化行为。通常，骨关节炎样品的粘弹性比以前研究的健康滑液低。在频率为2.5 Hz的滑液动态模量与蛋白质浓度之间观察到适度的相关性。发现温度会影响骨关节炎滑液的流变性，并符合Arrhenius模型。结论增加的蛋白质浓度与降低的剪切流变学参数有关。还证明了滑液的温度依赖性，并对其进行了建模，以用于本文的第2部分。但是，所有样品均表现出明显的非牛顿剪切稀化行为。通常，骨关节炎样品中的粘弹性比以前研究的健康滑液低。在频率为2.5 Hz的滑液动态模量与蛋白质浓度之间观察到适度的相关性。发现温度会影响骨关节炎滑液的流变性，并符合Arrhenius模型。结论增加的蛋白质浓度与降低的剪切流变学参数有关。滑液的温度依赖性也得到了证明，并在本文的第2部分中进行了建模。在频率为2.5 Hz的滑液动态模量与蛋白质浓度之间观察到适度的相关性。发现温度会影响骨关节炎滑液的流变性，并符合Arrhenius模型。结论增加的蛋白质浓度与降低的剪切流变学参数有关。还证明了滑液的温度依赖性，并对其进行了建模，以用于本文的第2部分。在频率为2.5 Hz的滑液动态模量与蛋白质浓度之间观察到适度的相关性。发现温度会影响骨关节炎滑液的流变性，并符合Arrhenius模型。结论增加的蛋白质浓度与降低的剪切流变学参数有关。还证明了滑液的温度依赖性，并对其进行了建模，以用于本文的第2部分。