Based on our recent study, which showed that cartilage fatigue failure in reciprocating sliding contact results from cyclical compressive forces, not from cyclical frictional forces, we hypothesize that a major functional role for synovial fluid (SF) is to reduce the rate of articular cartilage fatigue failure from cyclical compressive loading. The rate of cartilage fatigue failure due to repetitive compressive loading was measured by sliding a glass lens against an immature bovine cartilage tibial plateau strip immersed in mature bovine SF, phosphate-buffered saline (PBS), or SF/PBS dilutions (50% SF and 25% SF; n = 8 for all four bath conditions). After 24 h of reciprocating sliding (5400 cycles), samples were visually assessed, and if damage was observed, the test was terminated; otherwise, testing was continued for 72 h (16,200 cycles), with solution refreshed daily. All eight samples in the PBS group exhibited physical damage after 24 h, with an average final surface roughness of = 0.210 ± 0.067 mm. The SF group showed no damage after 24 h; however, two of eight samples became damaged after 72 h, producing a significantly lower average surface roughness than the PBS group (=0.059 ± 0.030 mm; p < ). For the remaining groups, at 72 h, one of eight samples was damaged in the 50% SF group, and five of eight samples were damaged in the 25% SF group. The results strongly support our hypothesis, showing that decreased amounts of SF in the testing bath produce increased rates of fatigue failure in cartilage that was subjected to reciprocating sliding contact.

中文翻译：

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滑液的主要功能作用是降低周期性压缩载荷下软骨疲劳失效的发生率


根据我们最近的研究，该研究表明往复滑动接触中的软骨疲劳失效是由周期性压缩力而不是周期性摩擦力引起的，我们假设滑液（SF）的主要功能作用是降低关节软骨疲劳率循环压缩载荷导致的失效。通过将玻璃镜片相对于浸入成熟牛 SF、磷酸盐缓冲盐水 (PBS) 或 SF/PBS 稀释液（50% SF 和25% SF；对于所有四种浴条件，n = 8）。 24小时往复滑动（5400次循环）后，对样品进行目视评估，如果观察到损坏，则终止测试；否则，测试将持续 72 小时（16,200 个循环），每天更新溶液。 PBS 组中的所有八个样品在 24 小时后均出现物理损坏，平均最终表面粗糙度 = 0.210 ± 0.067 mm。 SF组24小时后未见损伤；然而，8 个样品中有两个在 72 小时后损坏，产生的平均表面粗糙度明显低于 PBS 组（=0.059 ± 0.030 mm；p <）。对于其余组，在 72 小时时，50% SF 组的 8 个样品中的 1 个被损坏，25% SF 组的 8 个样品中的 5 个被损坏。结果有力地支持了我们的假设，表明测试浴中 SF 量的减少会导致遭受往复滑动接触的软骨疲劳失效率增加。