Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, United States; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112, United States.
Osteoarthritis Cartilage. 2013 Oct;21(10):1522-9. doi: 10.1016/j.joca.2013.06.008. Epub 2013 Jun 21.
A contributory factor to hip osteoarthritis (OA) is abnormal cartilage mechanics. Acetabular retroversion, a version deformity of the acetabulum, has been postulated to cause OA via decreased posterior contact area and increased posterior contact stress. Although cartilage mechanics cannot be measured directly in vivo to evaluate the causes of OA, they can be predicted using finite element (FE) modeling.
The objective of this study was to compare cartilage contact mechanics between hips with normal and retroverted acetabula using subject-specific FE modeling.
Twenty subjects were recruited and imaged: 10 with normal acetabula and 10 with retroverted acetabula. FE models were constructed using a validated protocol. Walking, stair ascent, stair descent and rising from a chair were simulated. Acetabular cartilage contact stress and contact area were compared between groups.
Retroverted acetabula had superomedial cartilage contact patterns, while normal acetabula had widely distributed cartilage contact patterns. In the posterolateral acetabulum, average contact stress and contact area during walking and stair descent were 2.6-7.6 times larger in normal than retroverted acetabula (P ≤ 0.017). Conversely, in the superomedial acetabulum, peak contact stress during walking was 1.2-1.6 times larger in retroverted than normal acetabula (P ≤ 0.044). Further differences varied by region and activity.
This study demonstrated superomedial contact patterns in retroverted acetabula vs widely distributed contact patterns in normal acetabula. Smaller posterolateral contact stress in retroverted acetabula than in normal acetabula suggests that increased posterior contact stress alone may not be the link between retroversion and OA.
髋关节骨关节炎（OA）的一个促成因素是软骨力学异常。髋臼后倾，即髋臼的一种畸形，通过减少后接触面积和增加后接触应力，被认为会导致 OA。虽然不能直接在体内测量软骨力学来评估 OA 的原因，但可以使用有限元（FE）建模进行预测。
本研究旨在使用基于个体的 FE 建模比较髋臼正常和后倾的髋关节的软骨接触力学。
共招募了 20 名受试者进行成像：10 名髋臼正常，10 名髋臼后倾。使用经过验证的方案构建 FE 模型。模拟了行走、上楼梯、下楼梯和从椅子上站起来。比较了两组之间的髋臼软骨接触压力和接触面积。
髋臼后倾表现为内侧上软骨接触模式，而髋臼正常表现为广泛分布的软骨接触模式。在髋臼后外侧，行走和下楼梯时的平均接触压力和接触面积在髋臼正常时比髋臼后倾时大 2.6-7.6 倍（P ≤ 0.017）。相反，在髋臼上内侧，行走时的峰值接触压力在髋臼后倾时比髋臼正常时大 1.2-1.6 倍（P ≤ 0.044）。其他差异因区域和活动而异。
本研究表明髋臼后倾时表现为内侧上接触模式，而髋臼正常时表现为广泛分布的接触模式。髋臼后倾时的后外侧接触压力较小，表明后接触压力增加本身可能不是后倾和 OA 之间的联系。
