Collier J P, Bargmann L S, Currier B H, Mayor M B, Currier J H, Bargmann B C
Dartmouth Biomedical Engineering Center, Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
Orthopedics. 1998 Aug;21(8):865-71. doi: 10.3928/0147-7447-19980801-09.
Hylamer and conventional polyethylene acetabular liners of the same design, revised for a variety of reasons, were examined and compared to assess the performance of Hylamer as a bearing material. Clinical damage modes, linear wear rates, oxidation levels, and mechanical properties were measured. In both series, many liners were retrieved for dislocation. Wear/osteolysis was the most common reason for retrieval in the Hylamer series, while none of the conventional polyethylene liners were retrieved for this reason. Nearly all liners exhibited abrasion, burnishing, scratching, and creep. The Hylamer liners had more cracking, delamination, and pitting. The Hylamer liners had an average linear wear rate of 0.32 mm/year, while the conventional polyethylene liners had an average wear rate of 0.20 mm/year. Due to sample size, no statistical difference in wear rate was noted between the two groups. In general, both the Hylamer and conventional polyethylene showed oxidation peaks subsurface, resulting from their exposure to gamma radiation in air. Liners with elevated oxidation had decreased ultimate tensile strength, elongation, and toughness. For given oxidation levels, the corresponding mechanical properties of Hylamer appeared lower than those of conventional polyethylene. The ultimate tensile strength values ranged from 14 to 33 MPa for Hylamer and 19 to 32 MPa for conventional polyethylene. Elongation ranges were 19% to 350% (Hylamer) and 80% to 375% (conventional). The Hylamer retrievals in this study gave initial indications of performance; Hylamer appeared to behave similarly, but not superiorly, to conventional polyethylene, in the early functional period with respect to clinical wear and clinical performance. Both Hylamer and conventional polyethylene liners were degraded by gamma sterilization in air, with Hylamer liners demonstrating greater property changes.
对因各种原因进行翻修的相同设计的海拉默（Hylamer）髋臼衬垫和传统聚乙烯髋臼衬垫进行了检查和比较，以评估海拉默作为一种轴承材料的性能。测量了临床损伤模式、线性磨损率、氧化水平和机械性能。在两个系列中，许多衬垫因脱位而被取出。磨损/骨溶解是海拉默系列中最常见的取出原因，而传统聚乙烯衬垫没有因此原因被取出。几乎所有衬垫都表现出磨损、抛光、刮擦和蠕变。海拉默衬垫有更多的裂纹、分层和点蚀。海拉默衬垫的平均线性磨损率为0.32毫米/年，而传统聚乙烯衬垫的平均磨损率为0.20毫米/年。由于样本量的原因，两组之间的磨损率没有统计学差异。总体而言，海拉默和传统聚乙烯在表面下均显示出氧化峰，这是它们在空气中受到伽马辐射所致。氧化程度升高的衬垫其极限拉伸强度、伸长率和韧性降低。对于给定的氧化水平，海拉默的相应机械性能似乎低于传统聚乙烯。海拉默的极限拉伸强度值范围为14至33兆帕，传统聚乙烯为19至32兆帕。伸长率范围分别为19%至350%（海拉默）和80%至375%（传统聚乙烯）。本研究中海拉默衬垫的取出情况给出了性能的初步迹象；在临床磨损和临床表现方面，海拉默在早期功能阶段的表现似乎与传统聚乙烯相似，但并不更优。海拉默和传统聚乙烯衬垫在空气中进行伽马灭菌时都会降解，海拉默衬垫的性能变化更大。
