Background:Physiological 0.9% saline is commonly used as an irrigation fluid in modern arthroscopy. There is a growing body of evidence that a hyperosmolar saline solution has chondroprotective effects, especially if iatrogenic injury occurs.Purpose:To (1) corroborate the superiority of a hyperosmolar saline solution regarding chondrocyte survival after mechanical injury and (2) observe the modulatory response of articular cartilage to osmotic stress and injury.Study Design:Controlled laboratory study.Methods:Osteochondral explants were isolated from bovine stifle joints and exposed to either 0.9% saline (308 mOsm) or hyperosmolar saline (600 mOsm) and then damaged with a sharp dermatome blade to attain a confined full-thickness cartilage injury site, incubated in the same fluids for another 3 hours, and transferred to chondropermissive medium for further culture for 1 week. Chondrocyte survival was assessed by confocal imaging, while the cellular response was evaluated over 1 week by relative gene expression for apoptotic and inflammatory markers and mediator release into the medium.Results:The full-thickness cartilage cut resulted in a confined zone of cell death that mainly affected superficial zone chondrocytes. Injured samples that were exposed to hyperosmolar saline showed less expansion of cell death in both the axial ( P < .007) and the coronal ( P < .004) plane. There was no progression of cell death during the following week of culture. Histological assessment revealed an intact cartilage matrix and normal chondrocyte morphology. Inflammatory and proapoptotic genes were upregulated on the first days postexposure with a notable downregulation toward day 7. Mediator release into the medium was concentrated on day 3.Conclusion:This in vitro cartilage injury model provides further evidence for the chondroprotective effect of a hyperosmolar saline irrigation fluid, as well as novel data on the capability of articular cartilage to quickly regain joint homeostasis after osmotic stress and injury.Clinical Relevance:Raising the osmolarity of an irrigating solution may be a simple and safe strategy to protect articular cartilage during arthroscopic surgery.

中文翻译：

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关节软骨对高渗压力的反应：离体损伤模型的报告

背景：现代关节镜检查常用0.9%生理盐水作为冲洗液。越来越多的证据表明高渗盐水溶液具有软骨保护作用，特别是在发生医源性损伤的情况下。目的：(1) 证实高渗盐水溶液在机械损伤后软骨细胞存活方面的优越性，(2) 观察调节反应研究设计：对照实验室研究。方法：从牛后膝关节分离骨软骨外植体，暴露于 0.9% 盐水 (308 mOsm) 或高渗盐水 (600 mOsm)，然后用锋利的工具破坏皮刀刀片以获得有限的全层软骨损伤部位，在相同的液体中再培养 3 小时，然后转移到软骨渗透培养基中进一步培养 1 周。通过共聚焦成像评估软骨细胞的存活率，并通过细胞凋亡和炎症标记物的相对基因表达以及介质释放到培养基中来评估 1 周内的细胞反应。 结果：全层软骨切割导致细胞死亡的限制区域主要影响浅层软骨细胞。暴露于高渗盐水的受损样品在轴向 (P < .007) 和冠状 (P < .004) 平面上显示细胞死亡扩张较少。在接下来的一周培养期间，细胞死亡没有进展。组织学评估显示完整的软骨基质和正常的软骨细胞形态。炎症和促凋亡基因在暴露后第一天上调，但到第 7 天则显着下调。介质释放到培养基中集中在第 3 天。结论：这种体外软骨损伤模型为高渗盐水冲洗的软骨保护作用提供了进一步的证据。液体，以及关于关节软骨在渗透压和损伤后快速恢复关节稳态能力的新数据。临床相关性：提高冲洗液的渗透压可能是关节镜手术期间保护关节软骨的简单而安全的策略。