The evolving large-strain shear responses of progressively osteoarthritic human cartilage
The evolving large-strain shear responses of progressively osteoarthritic human cartilage
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DOI：
10.1016/j.joca.2018.12.025
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发表时间：
2019-05-01
影响因子：
7
通讯作者：
Pierce, D. M.
中科院分区：
文献类型：
--
作者：
Maier, F.;Lewis, C. G.;Pierce, D. M.
目的：骨性关节炎（OA）发生发展过程中，关节软骨的组成和结构发生变化，导致力学反应发生变化。我们的目的是评估骨性关节炎进展过程中，由胶原蛋白和蛋白多糖及其相互作用控制的人类关节软骨固有的大应变力学的演变。设计：我们对10例全膝关节置换术（TKA）供体的64个标本进行准静态、大应变剪切试验，量化OA （OARSI评分）、结构完整性（PLM评分）和组成（糖胺聚糖和胶原含量）的相应状态。结果：我们观察到非线性应力-应变关系与所有施加应变大小的明显滞后，其中刚度，非线性和滞后都随着OA进展而降低。我们发现，与正常软骨（OA-1）相比，严重退行性软骨（OARSI分级4级，OA-4）的能量耗散密度降低高达80%，更重要的是，我们发现，即使是结构和成分外观正常的软骨（OA-1）的能量耗散也比健康（对照）承重软骨（h0）少50%。应力和刚度的变化通常不太明显，这使我们无法区分健康的承重对照和非常早期的OA (OA-1)，也无法一致区分不同程度的退变，即OARSI分级。结论：我们的研究结果表明，能量耗散密度的降低可以通过体组织测试检测到，并且这些降低先于可见的退化迹象。我们强调能量耗散的潜力，而不是基于应力或刚度的测量，作为诊断早期OA的标志。(C) 2019年国际骨关节炎学会。Elsevier Ltd.出版。版权所有。
Objective: The composition and structure of articular cartilage evolves during the development and progression of osteoarthritis (OA) resulting in changing mechanical responses. We aimed to assess the evolution of the intrinsic, large-strain mechanics of human articular cartilage-governed by collagen and proteoglycan and their interactions-during the progression of OA.Design: We completed quasi-static, large-strain shear tests on 64 specimens from ten donors undergoing total knee arthroplasty (TKA), and quantified the corresponding state of OA (OARSI grade), structural integrity (PLM score), and composition (glycosaminoglycan and collagen content).Results: We observed nonlinear stress-strain relationships with distinct hystereses for all magnitudes of applied strain where stiffnesses, nonlinearities, and hystereses all reduced as OA advanced. We found a reduction in energy dissipation density up to 80% in severely degenerated (OARSI grade 4, OA-4) vs normal (OA-1) cartilage, and more importantly, we found that even cartilage with a normal appearance in structure and composition (OA-1) dissipated 50% less energy than healthy (control) load-bearing cartilage (HL0). Changes in stresses and stiffnesses were in general less pronounced and did not allow us to distinguish between healthy load-bearing controls and very early-stage OA (OA-1), or to distinguish consistently among different levels of degeneration, i.e., OARSI grades.Conclusions: Our results suggest that reductions in energy dissipation density can be detected by bulk-tissue testing, and that these reductions precede visible signs of degeneration. We highlight the potential of energy dissipation, as opposed to stress-or stiffness-based measures, as a marker to diagnose early-stage OA. (C) 2019 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.