Takahashi Yasuhito, Masaoka Toshinori, Pezzotti Giuseppe, Shishido Takaaki, Tateiwa Toshiyuki, Kubo Kosuke, Yamamoto Kengo
Department of Bone and Joint Biomaterial Research, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan ; Department of Orthopaedic Surgery, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan.
Department of Orthopaedic Surgery, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan.
Biomed Res Int. 2014;2014:808369. doi: 10.1155/2014/808369. Epub 2014 Aug 27.
The present study investigated effects of processing procedures on morphology of highly cross-linked and re-melted UHMWPE (XLPE) in total hip and knee arthroplasty (THA, TKA). The shape recovery behavior was also monitored via uniaxial compression test at room temperature after non-destructive characterizations of the in-depth microstructure by confocal/polarized Raman spectroscopy. The goal of this study was to relate the manufacturing-induced morphology to the in vivo micromechanical performance, and ultimately to explore an optimal structure in each alternative joint bearing. It was clearly confirmed that the investigated XLPE hip and knee implants, which were produced from different orthopaedic grade resins (GUR 1050 and GUR 1020), consisted of two structural regions in the as-received states: the near-surface transitional anisotropic layer (≈100 μm thickness) and the bulk isotropic structural region. These XLPEs exhibited a different crystalline anisotropy and molecular texture within the near-surface layers. In addition, the knee insert showed a slightly higher efficiency of shape recovery against the applied strain over the hip liner owing to a markedly higher percentage of the bulk amorphous phase with intermolecular cross-linking. The quantitative data presented in this study might contribute to construct manufacturing strategies for further rationalized structures as alternative bearings in THA and TKA.
本研究调查了加工工艺对全髋关节和膝关节置换术（THA、TKA）中高度交联和再熔融超高分子量聚乙烯（XLPE）形态的影响。在通过共聚焦/偏振拉曼光谱对深度微观结构进行无损表征后，还通过室温下单轴压缩试验监测了形状恢复行为。本研究的目的是将制造过程中产生的形态与体内微观力学性能联系起来，并最终探索每种替代关节轴承的最佳结构。结果明确证实，所研究的由不同骨科级树脂（GUR 1050和GUR 1020）制成的XLPE髋关节和膝关节植入物，在初始状态下由两个结构区域组成：近表面过渡各向异性层（厚度约100μm）和本体各向同性结构区域。这些XLPE在近表面层内表现出不同的晶体各向异性和分子织构。此外，由于本体非晶相具有分子间交联的百分比明显更高，膝关节插入物相对于髋关节内衬在抵抗施加应变时表现出略高的形状恢复效率。本研究中提供的定量数据可能有助于构建制造策略，以获得更合理的结构作为THA和TKA中的替代轴承。
