Tauriainen Tuomas J T, Niinimäki Tuukka T, Niinimäki Jaakko L, Nousiainen Tomi O P, Leppilahti Juhana I
Division of Orthopaedic and Trauma Surgery, Department of Surgery, Oulu University Hospital, Medical Research Center, University of Oulu, Oulu, Finland.
Department of Diagnostic Radiology, Institute of Diagnostics, Oulu University Hospital, Medical Research Center, University of Oulu, Oulu, Finland.
J Arthroplasty. 2017 Jul;32(7):2204-2207. doi: 10.1016/j.arth.2017.02.009. Epub 2017 Feb 14.
The rate of and the reasons for the failure of metal-on-metal (MoM) bearings have recently been discussed in literature. The aim of this study was to evaluate the influence of acetabular cup inclination and version angles on revision risk in patients with MoM hip arthroplasty.
We retrospectively reviewed 825 patients (976 hips) who underwent a MoM hip arthroplasty between 2000 and 2013. There were 474 men and 351 women, with a mean age of 58 (19-86) years. Acceptable cup orientation was considered to be inside the Lewinnek's safe zone.
The mean acetabular inclination angle was 48.9° (standard deviation, 8.1°; range, 16°-76°) and version angle 20.6° (standard deviation, 9.9°; range, -25 to 46°). The cup was found to be outside the Lewinnek's safe zone in 571 hips (58.5%). Acetabular cup revision surgery was performed in 157 hips (16.1%). The cup angles were outside Lewinnek's safe zone in 69.2% of the revised hips. The mean interobserver reliability and intraobserver repeatability of the measurements of cup inclination and version angles were excellent (intraclass correlation coefficients >0.90). The odds ratio for revision in hips outside vs inside the Lewinnek's safe zone was 1.82 (95% confidence interval, 1.26-2.62; P = .0014).
Our findings provide compelling evidence that a cup position outside the Lewinnek's safe zone is associated with increased revision risk in patients with MoM arthroplasty.
金属对金属（MoM）关节轴承的失败率及原因最近在文献中已有讨论。本研究的目的是评估髋臼杯倾斜度和前倾角对MoM髋关节置换术患者翻修风险的影响。
我们回顾性分析了2000年至2013年间接受MoM髋关节置换术的825例患者（976髋）。其中男性474例，女性351例，平均年龄58（19 - 86）岁。可接受的髋臼杯方位被认为是在Lewinnek安全区内。
髋臼平均倾斜角为48.9°（标准差8.1°；范围16° - 76°），前倾角为20.6°（标准差9.9°；范围 - 25°至46°）。发现571髋（58.5%）的髋臼杯位于Lewinnek安全区之外。157髋（16.1%）进行了髋臼杯翻修手术。在翻修的髋关节中，69.2%的髋臼杯角度位于Lewinnek安全区之外。髋臼杯倾斜度和前倾角测量的观察者间可靠性和观察者内重复性均极佳（组内相关系数>0.90）。Lewinnek安全区外的髋关节与区内的髋关节相比，翻修的优势比为1.82（95%置信区间，1.26 - 2.62；P = .0014）。
我们的研究结果提供了令人信服的证据，表明Lewinnek安全区外的髋臼杯位置与MoM关节置换术患者的翻修风险增加相关。
