Department of Orthopaedic Surgery, Nihon University Itabashi Hospital, 30-1 Oyaguchikamimati Itabashi-ku, Tokyo 173-8610, Japan.
Department of Orthopaedic Surgery, Nihon University Itabashi Hospital, 30-1 Oyaguchikamimati Itabashi-ku, Tokyo 173-8610, Japan.
J Orthop Sci. 2022 May;27(3):558-562. doi: 10.1016/j.jos.2021.02.012. Epub 2021 Apr 15.
Although artificial joints using polyethylene have been developed for various joints, the development of Posterior Dynamic Stabilization system of the spine using polyethylene has proceeded at a much slower pace. There are no studies which compare the abrasion resistance of vitamin-E-blended crosslinked polyethylene (VE) and conventional polyethylene (Virgin) in the spinal region. The purpose of this study was to compare the wear resistance of VE and Virgin in a Posterior Dynamic Stabilization System of the spine.
Posterior Dynamic Stabilization System of the spine uses a polyethylene ball as a sliding surface. A fatigue wear test was repeated up to 1 million cycles at a speed of ±5°, 1 Hz while the rod was being pulled at a load of 50 N. Balls were compared using VE and Virgin in 6 samples each. Ti-6AL-4 V (Ti 64) and Co-Cr-Mo (CoCr) rods were used. Abrasion loss and shape change of the polyethylene balls were compared.
When Ti 64 was used as the rod, the average wear amount was -0.01 mg (0.02 mg, 0.01 mg, -0.06 mg) for VE, and 0.23 mg (0.18 mg, 0.13 mg, 0.38 mg) for Virgin. When CoCr was used as the rod, the average wear amount was 0.42 mg (0.71 mg, -0.06 mg, 0.61 mg) for VE, and 0.73 mg (0.72 mg, 0.70 mg, 0.76 mg) for Virgin. Most polyethylene samples showed indentations of 0.1 m or less at the contact point with the set screw. In the combination of Virgin and CoCr, a white patch was observed on the inner side of the polyethylene samples, with a maximum depression of 0.1 mm.
A fatigue wear test showed VE to be more efficient in abrasion resistance than Virgin in a Posterior Dynamic Stabilization System of the spine in the laboratory.
虽然已经开发出用于各种关节的聚乙烯人工关节，但脊柱后动态稳定系统的开发进展要慢得多。目前还没有研究比较脊柱区域维生素 E 交联聚乙烯（VE）和传统聚乙烯（Virgin）的耐磨性。本研究的目的是比较脊柱后路动态稳定系统中 VE 和 Virgin 的耐磨性。
脊柱后路动态稳定系统使用聚乙烯球作为滑动面。在速度为±5°、1 Hz 的情况下，以 50 N 的负荷拉动棒，重复进行疲劳磨损测试，直至达到 100 万次循环。在 6 个样本中，每个样本分别比较使用 VE 和 Virgin 的球。使用 Ti-6AL-4 V（Ti 64）和 Co-Cr-Mo（CoCr）棒。比较聚乙烯球的磨损失重和形状变化。
当 Ti 64 用作棒时，VE 的平均磨损量为-0.01mg（0.02mg、0.01mg、-0.06mg），Virgin 的平均磨损量为 0.23mg（0.18mg、0.13mg、0.38mg）。当 CoCr 用作棒时，VE 的平均磨损量为 0.42mg（0.71mg、-0.06mg、0.61mg），Virgin 的平均磨损量为 0.73mg（0.72mg、0.70mg、0.76mg）。大多数聚乙烯样品在与定位螺钉接触点处显示出 0.1m 或更小的压痕。在 Virgin 和 CoCr 的组合中，在聚乙烯样品的内侧观察到白色斑块，最大凹陷深度为 0.1mm。
疲劳磨损试验表明，在实验室中，脊柱后路动态稳定系统中 VE 的耐磨性优于 Virgin。
