Aurora A, DesJardins J D, Joseph P F, LaBerge M
Department of Bioengineering, Clemson University, Clemson, South Carolina 29634-0905, USA.
Proc Inst Mech Eng H. 2006 May;220(4):541-51. doi: 10.1243/09544119JEIM35.
Ultrahigh molecular weight polyethylene (UHMWPE) fatigue is a critical factor affecting the longevity of total knee replacement (TKR) bearings. With the increased need for laboratory studies to mimic near in vivo conditions for accurate characterization of material performance, the present study investigated the role of hyaluronic acid (HA) in testing lubricant on the crack growth response of UHMWPE. It was hypothesized that the change in lubricant viscosity as a result of HA would affect the fatigue life of the polymer. A fracture mechanics approach as per ASTM E 647 was adopted for this study. Surface micrograph and surface chemistry analyses were employed to study the micromechanisms of fatigue failure and protein adsorption of the specimen surfaces. Rheological analysis indicated that the addition of HA to diluted bovine serum increased testing lubricant viscosity. HA concentrations of 2.22, 0.55, and 1.5 g/l closely matched the viscosity ranges reported for osteoarthritis, rheumatoid arthritic diseased joint fluid, and periprosthetic fluids respectively. Results showed that the addition of HA to standard diluted bovine serum lubricants, in concentrations similar to that of periprosthetic fluid, delayed crack initiation and crack growth during fatigue testing.
超高分子量聚乙烯（UHMWPE）疲劳是影响全膝关节置换（TKR）轴承使用寿命的关键因素。随着实验室研究越来越需要模拟接近体内的条件以准确表征材料性能，本研究调查了透明质酸（HA）在测试润滑剂中对UHMWPE裂纹扩展响应的作用。研究假设是，HA导致的润滑剂粘度变化会影响聚合物的疲劳寿命。本研究采用了符合ASTM E 647的断裂力学方法。采用表面显微照片和表面化学分析来研究试样表面疲劳失效和蛋白质吸附的微观机制。流变学分析表明，向稀释的牛血清中添加HA会增加测试润滑剂的粘度。2.22、0.55和1.5 g/l的HA浓度分别与骨关节炎、类风湿性关节炎患病关节液和假体周围液报道的粘度范围密切匹配。结果表明，向标准稀释牛血清润滑剂中添加与假体周围液浓度相似的HA，在疲劳测试期间延迟了裂纹萌生和裂纹扩展。
