Sensitivity and specificity of blood cobalt and chromium metal ions for predicting failure of metal-on-metal hip replacement
Sensitivity and specificity of blood cobalt and chromium metal ions for predicting failure of metal-on-metal hip replacement
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DOI：
10.1302/0301-620x.93b10.26249
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发表时间：
2011-10-01
影响因子：
--
通讯作者：
Skinner, J. A.
中科院分区：
文献类型：
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作者：
Hart, A. J.;Sabah, S. A.;Skinner, J. A.
血金属离子已被广泛用于研究金属对金属髋关节置换术，但它们区分功能良好和失效髋关节的能力尚不清楚。药品和保健产品监管机构（MHRA）建议的临界值为十亿分之七（ppb）。我们对176例单侧金属对金属髋关节置换术患者进行了配对病例对照研究，探讨血液金属离子水平诊断失败的敏感性和特异性。我们招募了88例翻修前不明原因髋关节失败的患者，以及同等数量的髋关节功能良好的对照患者。我们研究了最大钴或铬的7 ppb截止水平，并从接收器工作特性曲线确定了最佳数学截止水平。在检测金属髋关节置换术前不明原因失效金属时，钴或铬的最高临界值为7 ppb，特异性为89%，敏感性为52%。钴或铬的最佳临界值为4.97 ppb，灵敏度为63%，特异性为86%。血金属离子具有较好的区分功能不良和功能良好的人工髋关节的能力。MHRA的截止水平为7 ppb，提供了一种特定的测试，但灵敏度较差。
Blood metal ions have been widely used to investigate metal-on-metal hip replacements, but their ability to discriminate between well-functioning and failed hips is not known. The Medicines and Healthcare products Regulatory Agency (MHRA) has suggested a cut-off level of 7 parts per billion (ppb).We performed a pair-matched, case-control study to investigate the sensitivity and specificity of blood metal ion levels for diagnosing failure in 176 patients with a unilateral metal-on-metal hip replacement. We recruited 88 cases with a pre-revision, unexplained failed hip and an equal number of matching controls with a well-functioning hip. We investigated the 7 ppb cut-off level for the maximum of cobalt or chromium and determined optimal mathematical cut-off levels from receiver-operating characteristic curves.The 7 ppb cut-off level for the maximum of cobalt or chromium had a specificity of 89% and sensitivity 52% for detecting a pre-operative unexplained failed metal on metal hip replacement. The optimal cut-off level for the maximum of cobalt or chromium was 4.97 ppb and had sensitivity 63% and specificity 86%.Blood metal ions had good discriminant ability to separate failed from well-functioning hip replacements. The MHRA cut-off level of 7 ppb provides a specific test but has poor sensitivity.