Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA.
Biomedical Engineering Practice, Exponent Inc, Menlo Park, CA.
J Arthroplasty. 2019 Dec;34(12):3088-3093. doi: 10.1016/j.arth.2019.07.018. Epub 2019 Jul 18.
In order to improve oxidation resistance, antioxidants such as vitamin-E are added to polyethylene used in the bearing surfaces of orthopedic components. Currently, little is known about the efficacy of this treatment in vivo. This study therefore reports on the reasons for revision, surface damage mechanisms, and oxidation of retrieved vitamin E-stabilized highly crosslinked polyethylene (HXLPE) for total knee arthroplasty.
We examined 103 retrieved knee inserts fabricated from vitamin E (VE)-stabilized HXLPE and 67 fabricated from remelted HXLPE as a control. The implantation times were 1.2 ± 1.3 and 1.5 ± 1.3 years for the VE and control cohorts, respectively. The inserts were evaluated for 7 surface damage mechanisms using a semiquantitative scoring method and analyzed for oxidation using Fourier-transform infrared spectroscopy. Reasons for revision were also assessed using operative notes created at time of retrieval.
Both groups were revised primarily for instability, infection, and loosening. Burnishing, pitting, and scratching were the most common damage mechanisms observed, with the VE cohort demonstrating less surface damage than the control. Measured oxidation for the cohort was low, with a median oxidation index of 0.09 ± .05 for the articulating surface, 0.05 ± 0.06 for the backside, 0.08 ± 0.06 for the anterior/posterior surfaces, and 0.08 ± 0.05 for the stabilizing post. As compared to the control cohort, oxidation tended to be less for the VE group at the articulating (P < .001) and backside (P = .003) surfaces, although the median differences were minimal and may not be clinically significant.
The results indicate positive fatigue damage resistance and oxidation resistance for the retrieved VE-stabilized total knee arthroplasty inserts.
为了提高抗氧化能力，在骨科部件的轴承表面所使用的聚乙烯中添加了抗氧化剂，如维生素 E。目前，人们对这种治疗方法在体内的疗效知之甚少。因此，本研究报告了在全膝关节置换术中，从体内取出的经维生素 E（VE）稳定的高度交联聚乙烯（HXLPE）的翻修原因、表面损伤机制和氧化情况。
我们检查了 103 个从维生素 E（VE）稳定的 HXLPE 中取出的膝关节植入物和 67 个从重熔 HXLPE 中取出的对照组。VE 组和对照组的植入时间分别为 1.2±1.3 年和 1.5±1.3 年。使用半定量评分法评估了 7 种表面损伤机制，并使用傅里叶变换红外光谱法分析了氧化情况。还使用取出时的手术记录评估了翻修的原因。
两组患者的翻修原因主要是不稳定、感染和松动。磨损、点蚀和划伤是最常见的损伤机制，VE 组的表面损伤比对照组少。测量的氧化值较低，关节表面的中位数氧化指数为 0.09±0.05，背面为 0.05±0.06，前/后表面为 0.08±0.06，稳定柱为 0.08±0.05。与对照组相比，VE 组在关节（P<0.001）和背面（P=0.003）表面的氧化程度较低，尽管中位数差异很小，可能没有临床意义。
结果表明，从体内取出的经 VE 稳定的全膝关节置换术植入物具有良好的抗疲劳损伤和抗氧化能力。
