What advantage is there to be gained using large modular metal-on-metal bearings in routine primary hip replacement? A PRELIMINARY REPORT OF A PROSPECTIVE RANDOMISED CONTROLLED TRIAL
What advantage is there to be gained using large modular metal-on-metal bearings in routine primary hip replacement? A PRELIMINARY REPORT OF A PROSPECTIVE RANDOMISED CONTROLLED TRIAL
复制标题
DOI：
10.1302/0301-620x.93b12.27533
复制
发表时间：
2011-12-01
影响因子：
--
通讯作者：
Holland, J. P.
中科院分区：
文献类型：
--
作者：
Malviya, A.;Ramaskandhan, J. R.;Holland, J. P.
本研究的目的是在一项前瞻性随机对照试验中，与直径为28 mm的传统金属对聚乙烯关节面相比，研究在初次髋关节置换术中股骨柄上使用大头金属对金属关节面的可能受益。我们使用Einzel-Bild-Rontgen-Analyse、临床和患者报告的测量（Harris髋关节评分、Western安大略和McMaster大学骨关节炎指数、简表-36和满意度）和2年时的全血金属离子水平研究了这两种不同关节面之间的骨水泥型股骨柄性能。一项功效研究表明，两组需要50个髋关节才能在2年时检测到下沉> 5 mm，p值<0.05。两组的平均临床和患者报告结局在2年时均显著改善（p < 0.001）。两组之间在2年时的结局比较显示，在平均股骨柄移位、临床和患者报告的结局方面没有统计学显著差异;除了金属对金属组的总体患者满意度更高（p = 0.05）。金属对金属组中20%的患者和金属对聚乙烯组中1例患者（对侧植入金属对金属植入物）的金属离子水平高于药品和保健产品管理局建议的安全水平（7 μ g/L）。金属对金属组中有2例患者接受了翻修，1例为假性肿瘤，1例为人工股骨头骨折。尽管使用了经表面置换证实的关节面，但使用大型组配式股骨头仍存在全血金属离子水平升高的风险。头颈部连接处或茎的过度微动可能是阻碍进一步研究的薄弱环节。
The aim of this study was to investigate the possible benefit of large-head metal-on-metal bearing on a stem for primary hip replacement compared with a 28 mm diameter conventional metal-on-polyethylene bearing in a prospective randomised controlled trial. We investigated cemented stem behaviour between these two different bearings using Einzel-Bild-Rontgen-Analyse, clinical and patient reported measures (Harris hip score, Western Ontario and McMaster Universities osteoarthritis index, Short Form-36 and satisfaction) and whole blood metal ion levels at two years. A power study indicated that 50 hips were needed in each group to detect subsidence of > 5 mm at two years with a p-value of < 0.05.Significant improvement (p < 0.001) was found in the mean clinical and patient reported outcomes at two years for both groups. Comparison of outcomes between the groups at two years showed no statistically significant difference for mean stem migration, clinical and patient reported outcomes; except overall patient satisfaction which was higher for metal-on-metal group (p = 0.05). Metal ion levels were raised above the Medicines and Healthcare products Regulatory Agency advised safety level (7 mu g per litre) in 20% of the metal-on-metal group and in one patient in metal-on-polyethylene group (who had a metal-on-metal implant on the contralateral side). Two patients in the metal-on-metal group were revised, one for pseudotumour and one for pen-prosthetic fracture.Use of large modular heads is associated with a risk of raised whole blood metal ion levels despite using a proven bearing from resurfacing. The head-neck junction or excess stem micromotion are possibly the weak links warranting further research.