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首页> 外文期刊>Journal of biomedical materials research. Part B, Applied biomaterials. >Potential thermal artifacts in hip joint wear simulators.
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Potential thermal artifacts in hip joint wear simulators.

机译：髋关节磨损模拟器中的潜在热伪影。

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Frictional heat was monitored during wear tests of ultrahigh molecular weight polyethylene acetabular cups bearing against femoral balls of metal or ceramic in a hip simulator, using bovine serum as a lubricant. About 1 to 2 h of continuous cycling were required for the temperature in the zone of contact between the cup and ball to rise to its maximum steady value, and this equilibrium temperature was markedly higher with increased load and/or cycling rate. Frictional heating caused substantial precipitation of the proteins from the serum and, in some of the tests running at 1.5 or 2 Hz, an adherent proteinaceous layer was observed attached to the surface of the balls. The maximum temperature was also substantially higher in tests run with the cup mounted above the ball rather than below. Surprisingly, the tests running at higher frictional torque and temperature (i.e., those with the most protein precipitation and/or adherent layers) produced the least wear of the polyethylene. This might have been due to the solid proteins that formed a protective layer between the ball and cup. Because patients with hip prostheses typically do not walk for hours without rest, the maximum temperatures in vivo are likely to be much lower than those reached in the hip simulator. Therefore, the affects of protein precipitation on the resultant wear properties of the materials should be considered potential artifacts of the hip simulator tests. Increasing the volume of the lubricant bath reduced the maximum temperatures for tests running at 1.5 Hz but had little affect at 2 Hz. Reducing the cycling rate is an effective way to avoid overheating of the specimens, but this necessarily extends the time required to complete a test. Copyright 1999 John Wiley & Sons, Inc.
机译：在超高分子量聚乙烯髋臼杯的磨损测试中，使用牛血清作为润滑剂，在髋关节模拟器中对金属或陶瓷的股骨球进行摩擦测试，以监测摩擦热。杯子和球之间的接触区域中的温度升高到其最大稳定值需要大约1-2小时的连续循环，并且随着负载和/或循环速率的增加，该平衡温度明显更高。摩擦加热使蛋白质从血清中大量沉淀出来，在某些以1.5或2 Hz进行的测试中，观察到附着的蛋白质层附着在球的表面。在将杯子安装在球上方而不是下方的情况下，最高温度也明显更高。令人惊讶地，在较高的摩擦扭矩和温度下进行的测试（即，具有最大蛋白质沉淀和/或粘附层的那些）产生的聚乙烯磨损最小。这可能是由于固体蛋白质在球和杯之间形成了保护层。由于具有髋关节假体的患者通常不休息数小时就不会走路，因此体内的最高温度可能会比在髋关节模拟器中达到的最高温度低得多。因此，应将蛋白质沉淀对材料最终磨损性能的影响视为髋部模拟器测试的潜在伪像。增加润滑剂浴的体积会降低在1.5 Hz下运行的测试的最高温度，但在2 Hz下几乎没有影响。降低循环速率是避免样品过热的有效方法，但这必然会延长完成测试所需的时间。版权所有1999 John Wiley＆Sons，Inc.

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