Ottawa Hospital, Divisionof Orthopaedic Surgery, University of Ottawa, 501Smyth Road Suite 5004, Ottawa, Ontario, K1H8L6, Canada.
Bone Joint Res. 2013 Aug 2;2(8):140-8. doi: 10.1302/2046-3758.28.2000173. Print 2013.
To quantify and compare peri-acetabular bone mineral density (BMD) between a monoblock acetabular component using a metal-on-metal (MoM) bearing and a modular titanium shell with a polyethylene (PE) insert. The secondary outcome was to measure patient-reported clinical function.
A total of 50 patients (25 per group) were randomised to MoM or metal-on-polyethlene (MoP). There were 27 women (11 MoM) and 23 men (14 MoM) with a mean age of 61.6 years (47.7 to 73.2). Measurements of peri-prosthetic acetabular and contralateral hip (covariate) BMD were performed at baseline and at one and two years' follow-up. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC), University of California, Los Angeles (UCLA) activity score, Harris hip score, and RAND-36 were also completed at these intervals.
At two years, only zone 1 showed a loss in BMD (-2.5%) in MoM group compared with a gain in the MoP group (+2.2%). Zone 2 showed loss in both groups (-2.2% for MoM; -3.9% for MoP) and zones 3 and 4 a gain in both groups (+0.1% for MoM; +3.3% for MoP). No other between-group differences were detected. When adjusting for BMD of the contralateral hip, no differences in BMD were observed. The only significant differences in functional scores at two years were higher UCLA activity (7.3 (sd 1.2) vs 6.1 (sd 1.5); p = 0.01) and RAND-36 physical function (82.1 (sd 13.0) vs 64.5 (sd 26.4); p = 0.02) for MoM bearings versus MoP. One revision was performed in the MoM group, for aseptic acetabular loosening at 11 months.
When controlling for systemic BMD, there were no significant differences between MoM and MoP groups in peri-acetabular BMD. However, increasing reports of adverse tissue reactions with large head MoM THR have restricted the use of the monoblock acetabular component to resurfacing only.
定量比较使用金属对金属（MoM）轴承的一体式髋臼组件和带聚乙烯（PE）衬垫的模块化钛壳之间的髋臼周围骨矿物质密度（BMD）。次要结果是测量患者报告的临床功能。
总共随机分配了 50 名患者（每组 25 名）使用 MoM 或金属对聚乙烯（MoP）。其中女性 27 名（MoM 组 11 名），男性 23 名（MoM 组 14 名），平均年龄 61.6 岁（47.7 至 73.2 岁）。在基线和 1 年和 2 年随访时，对髋臼周围假体和对侧髋关节（协变量）BMD 进行了测量。在这些时间点还完成了西安大略省和麦克马斯特大学骨关节炎指数（WOMAC）、加州大学洛杉矶分校（UCLA）活动评分、Harris 髋关节评分和 RAND-36。
在 2 年时，MoM 组的仅区域 1 显示 BMD 下降（-2.5%），而 MoP 组则显示 BMD 增加（+2.2%）。两组的区域 2 均显示 BMD 下降（MoM 组为-2.2%；MoP 组为-3.9%），而区域 3 和 4 则显示 BMD 增加（MoM 组为+0.1%；MoP 组为+3.3%）。未观察到其他组间差异。当调整对侧髋关节的 BMD 时，未观察到 BMD 存在差异。仅在 2 年时，MoM 组的 UCLA 活动评分（7.3（标准差 1.2）比 6.1（标准差 1.5）；p = 0.01）和 RAND-36 身体功能评分（82.1（标准差 13.0）比 64.5（标准差 26.4）；p = 0.02）更高。MoM 组中有 1 例因无菌性髋臼松动在 11 个月时进行了翻修。
当控制全身 BMD 时，MoM 和 MoP 组之间在髋臼周围 BMD 方面没有显著差异。然而，由于大直径 MoM THR 不良组织反应的报告不断增加，一体式髋臼组件的使用仅限于表面置换。
