Size and thickness effect on creep deformation of conventional and vitamin E-diffused highly crosslinked UHMWPE in total hip arthroplasty
Size and thickness effect on creep deformation of conventional and vitamin E-diffused highly crosslinked UHMWPE in total hip arthroplasty
复制标题
全髋关节置换术中常规和维生素E扩散高交联UHMWPE的尺寸和厚度对蠕变变形的影响
DOI：
10.1016/j.jmbbm.2016.05.020
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发表时间：
2016
影响因子：
3.9
通讯作者：
Kengo Yamamoto
中科院分区：
文献类型：
--
作者：
Yasuhito Takahashi ;Toshiyuki Tateiwa;Takaaki Shishido; Toshinori Masaoka;Kosuke Kubo;Kengo Yamamoto
自21世纪初以来，大股骨头在全髋关节置换术（THA）中的使用越来越普遍，可改善活动范围和关节稳定性。由于外壳尺寸有限（特别是对于骨盆尺寸较小的患者），大型股骨头通常需要与比常规使用的髋臼内衬更薄的髋臼内衬相结合。然而，衬套减薄对机械性能的影响仍然没有清楚地了解。本研究旨在通过实验阐明尺寸和厚度对传统（原始低交联）和维生素E扩散高交联超高分子量聚乙烯（UHMWPE）髋臼内衬压缩蠕变应变率的影响。我们在3000 N的恒定载荷下对这些不同内径（28、32和36 mm）和厚度（4.8、6.8和8.9 mm）的内衬施加单轴压缩，最长持续4320 min。维生素E扩散的高交联UHMWPE组件显示出比传统组件显著更高的抗蠕变性。在这两种类型的UHMWPE中，蠕变应变速率随着内径和厚度的增加而显著降低。改变构件厚度对蠕变行为的影响比改变构件内径大得多。我们的研究结果表明，使用大股骨头具有积极的机械优势，但同时，不建议为了最大限度地减少蠕变应变而进行相当大的内衬减薄。因此，有必要进行进一步的体外和体内研究，以在有限尺寸的外壳内得出股骨头直径和内衬厚度的最佳平衡。
Since the early 2000s, the use of large femoral heads is becoming increasingly popular in total hip arthroplasty (THA), which provides an improved range of motion and joint stability. Large femoral heads commonly necessitate to be coupled with thinner acetabular liners than the conventionally used because of the limited sizes of outer shells (especially for patients with small pelvic size). However, the influence of the liner thinning on the mechanical performance is still not clearly understood. The objective of this study was to experimentally clarify the size and thickness effect on the rates of compressive creep strain in conventional (virgin low-crosslinked) and vitamin E-diffused highly crosslinked, ultra-high molecular weight polyethylene (UHMWPE) acetabular liners. We applied uniaxial compression to these liners of various internal diameters (28, 32 and 36 mm) and thicknesses (4.8, 6.8 and 8.9 mm) up to 4320 min under the constant load of 3000 N. Vitamin E-diffused highly crosslinked UHMWPE components showed significantly greater creep resistance than the conventional ones. In the both types of UHMWPE, the rates of creep strain significantly decreased by increasing the internal diameter and thickness. Varying the component thickness contributed more largely to the creep behavior rather than the internal diameter. Our results suggest the positive mechanical advantage of using large femoral heads, but at the same time, a considerable liner thinning is not recommended for minimizing creep strain. Therefore, the furtherin-vitroas well asin-vivoresearch are necessary to conclude the optimal balance of head diameter and liner thickness within the limited sizes of outer shells.