Kupratis Meghan E, Gure Ahmed, Ortved Kyla F, Burris David L, Price Christopher
Biomedical Engineering, University of Delaware.
Bioengineering, University of Texas Arlington.
Biotribology (Oxf). 2021 Mar;25. doi: 10.1016/j.biotri.2020.100159. Epub 2020 Dec 31.
Articular cartilage is a robust tissue that facilitates load distribution and wear-free articulation in diarthrodial joints. These biomechanical capabilities are fundamentally tied to tissue hydration, whereby high interstitial fluid pressures and fluid load support facilitate the maintenance of low tissue strains and frictions. Our recent studies of cartilage sliding biomechanics using the convergent stationary contact area (cSCA) configuration, first introduced by Dowson and colleagues, unexpectedly demonstrated that sliding alone can promote recovery of interstitial pressure and lubrication lost to static compression through a mechanism termed 'tribological rehydration.' Although exclusively examined in bovine stifle cartilage to date, we hypothesized that tribological rehydration, i.e., the ability to recover/modulate tissue strains and lubrication through sliding, is a universal behavior of articular cartilage. This study aimed to establish if, and to what extent, sliding-induced tribological rehydration is conserved in articular cartilage across a number of preclinical animal species/models and diarthrodial joints. Using a comparative approach, we found that articular cartilage from equine, bovine, ovine, and caprine stifles, and porcine stifle, hip, and tarsal joints all exhibited remarkably consistent sliding speed-dependent compression/strain recovery and lubrication behaviors under matched contact stresses (0.25 MPa). All cartilage specimens tested supported robust, tribological rehydration during high-speed sliding (>30 mm/s), which as a result of competitive recovery of interstitial lubrication, promoted remarkable decreases in kinetic friction during continuous sliding. The conservation of tribological rehydration across mammalian quadruped articular cartilage suggests that sliding-induced recovery of interstitial hydration represents an important tissue adaptation and largely understudied contributor to the biomechanics of cartilage and joints.
关节软骨是一种坚韧的组织，可促进滑膜关节中的负荷分布和无磨损关节活动。这些生物力学能力从根本上与组织水合作用相关，即高组织间隙液压和流体负荷支撑有助于维持低组织应变和摩擦力。我们最近使用由道森及其同事首次引入的收敛固定接触面积（cSCA）配置对软骨滑动生物力学进行的研究意外地表明，仅滑动就可以通过一种称为“摩擦学再水化”的机制促进因静态压缩而损失的组织间隙压力和润滑的恢复。尽管迄今为止仅在牛膝关节软骨中进行了研究，但我们推测摩擦学再水化，即通过滑动恢复/调节组织应变和润滑的能力，是关节软骨的普遍行为。本研究旨在确定在多种临床前动物物种/模型和滑膜关节的关节软骨中，滑动诱导的摩擦学再水化是否存在以及在何种程度上存在。通过比较研究方法，我们发现来自马、牛、羊和山羊膝关节以及猪膝关节、髋关节和跗关节的关节软骨在匹配的接触应力（0.25 MPa）下均表现出明显一致的与滑动速度相关的压缩/应变恢复和润滑行为。所有测试的软骨标本在高速滑动（>30 mm/s）期间均支持强大的摩擦学再水化，由于组织间隙润滑的竞争性恢复，在连续滑动过程中促进了动摩擦的显著降低。哺乳动物四足动物关节软骨中摩擦学再水化的保守性表明，滑动诱导的组织间隙水合作用恢复代表了一种重要的组织适应性，并且在很大程度上是软骨和关节生物力学中尚未得到充分研究的因素。
