Department of Trauma and Orthopedic Surgery, Berufsgenossenschaftliche Unfallklinik Frankfurt am Main, Frankfurt, Germany.
Interdisciplinary Center for Clinical Studies, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
Bone Joint J. 2022 Mar;104-B(3):376-385. doi: 10.1302/0301-620X.104B3.BJJ-2021-0492.R2.
This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant.
A total of 63 patients (65 implants) were treated using either a MoM-coated (n = 29) or TiN-coated (n = 7) hinged TKA (GenuX mobile bearing, MUTARS; Implantcast, Germany) versus the BPKS (Brehm, Germany) hinged TKA (n = 27), in which the weight placed on the MoM hinge is diffused through a polyethylene (PE) inlay, reducing the direct load on the MoM hinge. Serum cobalt and chromium ion concentrations were assessed after minimum follow-up of 12 months, as well as functional outcome and quality of life.
No differences in mean age (69 years, 40 to 86), mean age adapted Charlson Comorbidity Index (3.1 (SD 1.4)), mean BMI (29.2 kg/m (SD 5.8)), or number of other implants were observed between groups. Significant improvements in outcome scores and pain levels were achieved for all groups, and there was no difference in quality of life (12-Item Short-Form Health Survey questionnaire (SF-12)). Mean cobalt and chromium ion levels were significantly higher for the GenuX versus the BPKS hinged TKA (GenuX vs BPKS: cobalt: 16.3 vs 9.4 µg/l; chromium: 9.5 vs 5.2 µg/l). The TiN-coated implants did not appear to confer improvement in the metal ion levels. Metal ion concentrations above 7 µg/l were detected in 81%(29/36) of GenuX patients versus 41% (11/27) in the BPKS group. No GenuX patients had normal levels under 2 µg/l, versus 22% of BPKS patients. No significant reduction in outcome scores was observed regardless of the metal ion levels, whereas higher work-related activity was correlated with higher chromium concentrations.
Hinged TKA, using MoM hinges, resulted in critically high cobalt and chromium ion concentrations. The BPKS hinged TKA showed significantly lower metal ion concentrations compared with the GenuX TKA. No benefits were observed using TiN coating. The different weightbearing mechanics might influence the wear of the component materials. Higher workloads and physical activity could influence chromium levels. Cite this article: 2022;104-B(3):376-385.
本研究比较了两种不同的金属对金属（MoM）铰链式全膝关节置换术（TKA）系统以及氮化钛（TiN）涂层变体的钴和铬血清离子浓度。
共有 63 名患者（65 个植入物）接受了 MoM 涂层（n = 29）或 TiN 涂层（n = 7）铰链式 TKA（GenuX 活动式轴承，MUTARS；Implantcast，德国）或 BPKS（Brehm，德国）铰链式 TKA（n = 27）的治疗，其中 MoM 铰链上的重量通过聚乙烯（PE）衬垫扩散，从而减少 MoM 铰链的直接负荷。在至少 12 个月的随访后，评估了血清钴和铬离子浓度，以及功能结果和生活质量。
各组间的平均年龄（69 岁，40 至 86 岁）、平均年龄调整 Charlson 合并症指数（3.1（SD 1.4））、平均 BMI（29.2kg/m（SD 5.8））或其他植入物数量无差异。所有组的结果评分和疼痛水平均显著改善，生活质量（12 项简短健康调查问卷（SF-12））无差异。GenuX 铰链式 TKA 的钴和铬离子水平明显高于 BPKS 铰链式 TKA（GenuX 比 BPKS：钴：16.3 比 9.4µg/l；铬：9.5 比 5.2µg/l）。TiN 涂层植入物似乎并未改善金属离子水平。GenuX 患者中有 81%（29/36）检测到钴离子浓度超过 7µg/l，而 BPKS 组中为 41%（11/27）。GenuX 患者无一例低于 2µg/l，而 BPKS 患者中有 22%。无论金属离子水平如何，结果评分均无明显下降，而与工作相关的活动量较高与较高的铬浓度相关。
使用 MoM 铰链的铰链式 TKA 导致钴和铬离子浓度极高。BPKS 铰链式 TKA 的金属离子浓度明显低于 GenuX TKA。TiN 涂层没有明显的益处。不同的负重力学可能会影响部件材料的磨损。更高的工作量和体力活动可能会影响铬水平。
2022;104-B（3）：376-385.
