Miller Kirsten C, Holloway Matthew B, Morrow Brian R, Smith Richard A, Mihalko William M
Department of Orthopaedic Surgery and Biomedical Engineering, School of Medicine, University of Tennessee Health Science Center, Memphis, TN.
College of Medicine, University of Tennessee Health Science Center, Memphis, TN.
J Arthroplasty. 2022 Jun;37(6S):S355-S363. doi: 10.1016/j.arth.2022.01.062. Epub 2022 Feb 24.
Patients have received cobalt-chromium-molybdenum (CoCrMo) implants for their joint replacement for decades. There have been reports of inflammatory cell-induced corrosion (ICIC) of these implants from retrieval studies. The goal of this study is to see if we could recreate ICIC in vitro and whether electrocautery damage to alloy surfaces may hasten this process.
Murine macrophages were cultured on CoCr disks with and without damage from a monopolar electrocautery. Culture medium was replaced every 12 hours and supernatant was collected every 4 days. After 30 days, cells were removed, counted, and digested. The metal concentrations in the supernatant and within cells were assessed using inductively coupled plasma spectrometry for comparison.
The Co supernatant concentration was higher in the undamaged disks with activated macrophages. Higher concentrations of Co and Mo were found in the supernatant of the undamaged disks vs the electrocautery (EC) corrosion damaged disks. There was a significantly higher intracellular Co and Mo concentration with activated cells on CoCrMo disks vs the control group and no difference compared to EC damaged disk group. Scanning electron microscopy displayed microscopic pitting on the surfaces exposed to macrophages without EC damage.
We found that macrophages could reproduce findings of ICIC pits on the surface of CoCrMo alloy and that the addition of EC damage to the surface did not increase the process. The clinical significance of these findings should be further investigated to determine if this could explain a small number of poor total knee arthroplasty reported outcomes.
患者接受钴铬钼（CoCrMo）植入物进行关节置换已有数十年。检索研究报告了这些植入物存在炎症细胞诱导腐蚀（ICIC）的情况。本研究的目的是观察我们能否在体外重现ICIC，以及电灼对合金表面的损伤是否会加速这一过程。
将小鼠巨噬细胞培养在有或没有单极电灼损伤的CoCr盘上。每12小时更换一次培养基，每4天收集一次上清液。30天后，去除细胞，计数并消化。使用电感耦合等离子体质谱法评估上清液和细胞内的金属浓度以进行比较。
在有活化巨噬细胞的未受损盘片中，Co上清液浓度较高。与电灼（EC）腐蚀损伤的盘片相比，未受损盘片的上清液中Co和Mo的浓度更高。与对照组相比，CoCrMo盘上有活化细胞时细胞内Co和Mo浓度显著更高，与EC损伤盘片组相比无差异。扫描电子显微镜显示，在未受EC损伤且暴露于巨噬细胞的表面有微观点蚀。
我们发现巨噬细胞可以在CoCrMo合金表面重现ICIC凹坑的现象，并且表面添加EC损伤并不会加速这一过程。这些发现的临床意义应进一步研究，以确定这是否可以解释少数全膝关节置换术报告的不良结果。
