Missouri Bone & Joint Research Foundation, St Louis, Missouri, USA.
Bone Joint J. 2021 Jun;103-B(6 Supple A):94-101. doi: 10.1302/0301-620X.103B6.BJJ-2020-2429.R1.
The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components.
Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.
We found that the surface roughness of CoCr components rapidly increased during the first 1,000 wear cycles, then reached a steady state, but material loss from the surface continued at a rate of 1,778,000 μm per million cycles as carbides were removed from its matrix. These carbides formed third-body wear particles, leading to the formation of new scratches even as older scratches were worn away. In contrast, no scratching, loss of material, or other surface damage, when evaluated with one nanometer resolution, was found on the surface of the ceramic components after a 15 M wear cycle test.
This study showed wear and loss of CoCr material from scratching and microabrasive wear in TKA. The material loss from the surface continued in a linear relationship with increasing cycles. We also found the absence of scratching and roughening of ceramic femoral components in simulated wear, suggesting an advantage in wear rate and avoiding metal sensitivity. This may have implications in the management of persistent pain after TKA. Cite this article: 2021;103-B(6 Supple A):94-101.
本研究旨在评估全膝关节置换术中钴铬（CoCr）股骨部件的表面磨损情况，并比较这些部件与陶瓷股骨部件的磨损情况。
采用光学轮廓法评估表面粗糙度，并在膝关节磨损模拟器中检查磨损过程中产生的特征。我们开发了一种测量五个 CoCr 股骨部件表面变化的方法，并量化了磨损过程中关节表面材料的损失。我们还检查了之前测试的三个陶瓷股骨部件的关节表面是否有表面损伤的证据，并与 CoCr 部件进行了比较。
我们发现，CoCr 部件的表面粗糙度在最初的 1000 个磨损循环中迅速增加，然后达到稳定状态，但由于其基质中的碳化物被去除，表面材料的损失仍以每百万循环 1778000μm 的速度持续增加。这些碳化物形成了第三体磨损颗粒，导致即使旧划痕被磨损，新划痕也会形成。相比之下，在经过 1500 万次磨损循环测试后，陶瓷部件的表面没有划痕、材料损失或其他表面损伤，评估分辨率为 1nm。
本研究表明，TKA 中 CoCr 材料会因刮擦和微磨料磨损而磨损和损失。表面材料的损失与循环次数呈线性关系持续增加。我们还发现模拟磨损中陶瓷股骨部件没有出现刮擦和粗糙度增加，表明其具有较低的磨损率和避免金属敏感性的优势。这可能对 TKA 后持续性疼痛的管理具有重要意义。
2021;103-B（6 增刊 A）：94-101.
