Kasparek Maximilian F, Renner Lisa, Faschingbauer Martin, Waldstein Wenzel, Weber Michael, Boettner Friedrich
Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA.
Department of Orthopedics, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
Arch Orthop Trauma Surg. 2018 Feb;138(2):281-286. doi: 10.1007/s00402-017-2856-y. Epub 2017 Dec 19.
Although metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacings (HR) have similar bearing surfaces and comparable wear rates, metal ion levels and risk of failure are higher for MoM-THA. The mechanism behind the increased metal ion levels in large head MoM-THA is not completely understood. The current study aims to identify predictive factors for increased metal ion levels in unilateral and bilateral large head MoM-THA.
99 Birmingham modular MoM-THA in 87 patients with metal ion levels at least 36 months after index procedure were analyzed. Mean follow-up time was 61.3 months (range 37-108) and the relationship of the following variables (gender, age, BMI, follow-up time, UCLA Activity Score, cup inclination, femoral head size, bilateral surgery) on metal ion levels were analyzed with multivariate regression models.
Multivariate regression analysis revealed that bilateral MoM-THA surgery (p < 0.001) had a positive predictive effect on cobalt serum levels, while BMI had a negative (p = 0.018). Female gender (p = 0.012), activity (p = 0.001) and bilateral MoM-THA (p = 0.004) were positively correlated with chromium levels. Positive independent predictors for the cobalt-chromium ratio in the multivariate analysis were overall follow-up time (p = 0.004), bilateral MoM-THA (p < 0.001) and femoral head size (p = 0.007).
The data of the current study suggest that bilateral MoM-THA, increased patient activity levels and female gender are associated with increased chromium levels. Patients with larger component size, longer follow-up time and bilateral MoM-THAs have an increased cobalt-chromium ratio. These patients might be at increased risk for adverse local soft tissue reactions secondary to corrosion. Continuous close monitoring is recommended and bearing-surface change should be discussed if local tissue reactions occur.
尽管金属对金属（MoM）全髋关节置换术（THA）和髋关节表面置换术（HR）具有相似的关节面和相近的磨损率，但MoM-THA的金属离子水平和失败风险更高。大头MoM-THA中金属离子水平升高背后的机制尚未完全明确。本研究旨在确定单侧和双侧大头MoM-THA中金属离子水平升高的预测因素。
对87例患者的99例伯明翰模块化MoM-THA进行分析，这些患者在初次手术后至少36个月有金属离子水平数据。平均随访时间为61.3个月（范围37 - 108个月），并使用多变量回归模型分析以下变量（性别、年龄、体重指数、随访时间、加州大学洛杉矶分校活动评分、髋臼杯倾斜度、股骨头大小、双侧手术）与金属离子水平之间的关系。
多变量回归分析显示，双侧MoM-THA手术（p < 0.001）对钴血清水平有正向预测作用，而体重指数有负向作用（p = 0.018）。女性（p = 0.012）、活动量（p = 0.001）和双侧MoM-THA（p = 0.004）与铬水平呈正相关。多变量分析中钴铬比的正向独立预测因素为总体随访时间（p = 0.004）、双侧MoM-THA（p < 0.001）和股骨头大小（p = 0.007）。
本研究数据表明，双侧MoM-THA、患者活动水平增加和女性性别与铬水平升高有关。假体部件尺寸较大、随访时间较长和双侧MoM-THA的患者钴铬比增加。这些患者可能因腐蚀继发局部软组织不良反应的风险增加。建议持续密切监测，若发生局部组织反应，应讨论关节面更换问题。
