Fatigue crack propagation resistance of virgin and highly crosslinked, thermally treated ultra-high molecular weight polyethylene
Fatigue crack propagation resistance of virgin and highly crosslinked, thermally treated ultra-high molecular weight polyethylene
复制标题
DOI：
10.1016/j.biomaterials.2005.09.010
复制
发表时间：
2006-03-01
期刊：
影响因子：
14
通讯作者：
Kurtz, SM
中科院分区：
文献类型：
--
作者：
Gencur, SJ;Rimnac, CM;Kurtz, SM
为了延长全关节置换的使用寿命，已引入高度交联的超高分子量聚乙烯（HDPE）来提高关节面的耐磨性。然而，存在关于延展性损失和疲劳裂纹扩展（FCP）抗性的潜在损失的担忧。本研究的目的是评价伽马辐照诱导交联与两种不同的辐照后热处理对UHMWPE耐FCP性的影响。检查了两个高交联UHMWPE处理组和一个原始UHMWPE处理组（冲压挤出，骨科级，GUR 1050）。对于两个高交联处理组，将UHMWPE棒暴露于100 kGy，然后在高于熔融温度或低于熔融温度（2 h-150 ℃，110 ℃）下进行辐照后热处理。对紧凑型拉伸样本进行循环加载直至失效，测定疲劳裂纹扩展速率da/dN与循环应力强度因子Δ K的关系，并在组间进行比较。扫描电子显微镜观察断裂表面特征，发现交联降低了UHMWPE在循环载荷下抵抗裂纹萌生和扩展的能力。研究结果还表明，退火作为辐照后处理可能比重熔对UHMWPE的FCP耐受性的损害更小。断裂表面的扫描电子显微镜检查表明，与两个高度交联的治疗组相比，原始治疗组以更具延展性的方式失效。(c)2005年由Elsevier Ltd.出版
To prolong the life of total joint replacements, highly crosslinked ultra-high molecular weight polyethylenes (UHMWPEs) have been introduced to improve the wear resistance of the articulating surfaces. However, there are concerns regarding the loss of ductility and potential loss in fatigue crack propagation (FCP) resistance. The objective of this study was to evaluate the effects of gamma radiation-induced crosslinking with two different post-irradiation thermal treatments on the FCP resistance of UHMWPE. Two highly crosslinked and one virgin UHMWPE treatment groups (ram-extruded, orthopedic grade, GUR 1050) were examined. For the two highly crosslinked treatment groups, UHMWPE rods were exposed to 100 kGy and then underwent post-irradiation thermal processing either above the melt temperature or below the melt temperature (2 h-150 degrees C, 110 degrees C). Compact tension specimens were cyclically loaded to failure and the fatigue crack growth rate, da/dN, vs. cyclic stress intensity factor, Delta K, behavior was determined and compared between groups. Scanning electron microscopy was used to examine fracture surface characteristics.Crosslinking was found to decrease the ability of UHMWPE to resist crack inception and propagation under cyclic loading. The findings also suggested that annealing as a post-irradiation treatment may be somewhat less detrimental to FCP resistance of UHMWPE than remelting. Scanning electron microscopy examination of the fracture surfaces demonstrated that the virgin treatment group failed in a more ductile manner than the two highly crosslinked treatment groups. (c) 2005 Published by Elsevier Ltd.