Segmental acetabular rim defects, bone loss, oversizing, and press fit cup in total hip arthroplasty evaluated with a probabilistic finite element analysis
Segmental acetabular rim defects, bone loss, oversizing, and press fit cup in total hip arthroplasty evaluated with a probabilistic finite element analysis
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DOI：
10.1007/s00264-016-3369-y
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发表时间：
2017-08-01
影响因子：
2.7
通讯作者：
Bobko, Aimee
中科院分区：
文献类型：
--
作者：
Amirouche, Farid;Solitro, Giovanni F.;Bobko, Aimee
目的 在髋臼骨丢失的分类系统中，全髋关节置换术前老年人节段性边缘缺损和骨矿物质密度 (BMD) 丢失的处理尚不清楚。在这项研究中，我们的目标是（1）了解老年人骨密度的降低如何影响用于初次固定的压配合杯的尺寸过大，以及（2）评估节段性缺损的位置是否影响杯固定。方法使用有限元（FE）模型来模拟和评估节段性边缘缺损情况下杯的插入和固定。我们关注 70 岁以上患者的分布，并使用 BMD（根据 CT 估计）作为衰老对 THR 影响的代理，并使用概率 FE 分析来了解 BMD 损失如何影响压配罩杯尺寸过大。结果 尺寸过大 1.10 +/- 0.28 mm 的罩杯可为老年患者提供足够的固定并降低罩杯骨界面处的应力。与对照配置相比，前柱和后柱缺陷均需要 84% 的平均插入力（取 2 个前柱缺陷和 2 个后柱缺陷的平均值），比上缘缺陷的插入力大 5%，比下缘缺陷的插入力大 12%。结论 沿上缘或下缘的缺陷对杯子固定的影响最小，而柱中的缺陷会导致杯子不稳定并增加应力在缺陷位置。
Purpose Management of segmental rim defects and bone mineral density (BMD) loss in the elderly prior to total hip replacement is unclear within classification systems for acetabular bone loss. In this study, our objectives were (1) to understand how a reduction in BMD in the elderly affects the oversizing of a press-fit cup for primary fixation and (2) to evaluate whether the location of the segmental defect affected cup fixation.Methods A finite element (FE) model was used to simulate and evaluate cup insertion and fixation in the context of segmental rim defects. We focused on the distribution of patients over age 70 and used BMD (estimated from CT) as a proxy for aging's implications on THR and used probabilistic FE analysis to understand how BMD loss affects oversizing of a press-fit cup.Results A cup oversized by 1.10 +/- 0.28 mm provides sufficient fixation and lower stresses at the cup-bone interface for elderly patients. Defects in the anterior column and posterior column both required the same mean insertion force for cup seating of 84% (taken as an average of 2 anterior column and 2 posterior column defects) compared to the control configuration, which was 5% greater than the insertion force for a superior rim defect and 12% greater than the insertion force for an inferior rim defect.Conclusions A defect along the superior or inferior rim had a minimal effect on cup fixation, while a defect in the columns created cup instability and increased stress at the defect location.