Edidin A A, Pruitt L, Jewett C W, Crane D J, Roberts D, Kurtz S M
Stryker Howmedica Osteonics, Allendale, New Jersey 07401, USA.
J Arthroplasty. 1999 Aug;14(5):616-27. doi: 10.1016/s0883-5403(99)90086-4.
The mechanism for the improved wear resistance of cross-linked ultra-high-molecular-weight polyethylene (UHMWPE) remains unclear. This study investigated the effect of cross-linking achieved by gamma irradiation in nitrogen on the tribologic, mechanical, and morphologic properties of UHMWPE. The goal of this study was to relate UHMWPE properties to the wear mechanism in acetabular-bearing inserts. Wear simulation of acetabular liners was followed by detailed characterization of the mechanical behavior and crystalline morphology at the articulating surface. The wear rate was determined to be directly related to the ductility, toughness, and strain-hardening behavior of the UHMWPE. The concept of a plasticity-induced damage layer is introduced to explain the near-surface orientation of the crystalline lamellae observed in the wear-tested acetabular liners. Cross-linking reduces abrasive wear of acetabular components by substantially reducing--but not eliminating--the plasticity-induced damage layer that precedes abrasive wear.
交联超高分子量聚乙烯（UHMWPE）耐磨性提高的机制仍不清楚。本研究调查了在氮气中通过γ射线辐照实现的交联对UHMWPE摩擦学、力学和形态学性能的影响。本研究的目的是将UHMWPE性能与髋臼承重内衬的磨损机制联系起来。在对髋臼内衬进行磨损模拟之后，详细表征了其在关节表面的力学行为和结晶形态。磨损率被确定与UHMWPE的延展性、韧性和应变硬化行为直接相关。引入了塑性诱导损伤层的概念来解释在磨损测试的髋臼内衬中观察到的结晶薄片的近表面取向。交联通过大幅减少（但不是消除）磨损前的塑性诱导损伤层，降低了髋臼部件的磨料磨损。
