Avon Orthopaedic Centre, Brunel Building, Southmead Hospital, North Bristol NHS Trust, Bristol, UK.
Department of Emergency Medicine, Central Michigan University College of Medicine, MI, USA.
Hip Int. 2020 Nov;30(6):761-774. doi: 10.1177/1120700019866428. Epub 2020 Sep 15.
The major joint registries report better survivorship for ceramic on polyethylene over metal on polyethylene bearings in total hip arthroplasty and it is generally accepted that this is due to a lower polyethylene wear rate. We used evidence synthesis to compare survivorship, polyethylene wear rates and metal ion levels for metal-on-polyethylene (MoP) and ceramic-on-polyethylene (CoP) bearings. If wear rates are not dissimilar this difference in revision rate may have another cause. Modular junctions are a potential source of corrosion and it is postulated that this may result in higher revision rates.
We performed a systematic review and meta-analysis comparing the survivorship of MoP and CoP bearings. Odds ratio (95% CI) of revision was calculated. Mean difference (MD) and 95% confidence intervals (CI) were used to compare secondary outcomes of polyethylene wear and metal ion levels. Meta-analysis was performed with a Mantel-Haenszel Random-Effects Model.
6 randomised controlled trials were included. There was no statistically significant difference between MoP and CoP revision rate (OR 1.04; 95% CI, 0.37-2.90, I = 0%, 0.94), linear bearing wear (MD 0.00 mm; 95% CI, -0.05 -0.05, I = 98%, 0.90), nor volumetric bearing wear (MD 33.57 mm; 95% CI, -215.56-282.70, I = 98%, 0.79). No studies evaluated metal ion levels.
We found no evidence of a difference in revision rates nor linear and volumetric wear between MoP and CoP bearings in the randomised controlled trials currently available. Our study therefore does not advocate the additional cost associated with the use of ceramic heads in combination with polyethylene bearings in order to minimise revision rates. This contrasts the findings of studies and the major joint registries.
主要关节登记处报告称，全髋关节置换术中陶瓷对聚乙烯的生存率优于金属对聚乙烯，这通常归因于较低的聚乙烯磨损率。我们使用证据综合方法比较了金属对聚乙烯（MoP）和陶瓷对聚乙烯（CoP）轴承的生存率、聚乙烯磨损率和金属离子水平。如果磨损率没有差异，那么这种翻修率的差异可能有其他原因。模块化接头是腐蚀的潜在来源，据推测这可能导致更高的翻修率。
我们进行了一项系统评价和荟萃分析，比较了 MoP 和 CoP 轴承的生存率。计算了翻修的优势比（95%置信区间）。使用均值差（MD）和 95%置信区间（CI）比较聚乙烯磨损和金属离子水平的次要结局。使用 Mantel-Haenszel 随机效应模型进行荟萃分析。
纳入了 6 项随机对照试验。MoP 和 CoP 翻修率之间没有统计学上的显著差异（OR 1.04；95%CI，0.37-2.90，I = 0%，0.94），线性轴承磨损（MD 0.00mm；95%CI，-0.05-0.05，I = 98%，0.90），也没有容积轴承磨损（MD 33.57mm；95%CI，-215.56-282.70，I = 98%，0.79）。没有研究评估金属离子水平。
我们发现，在目前可用的随机对照试验中，MoP 和 CoP 轴承之间在翻修率以及线性和容积磨损方面没有差异。因此，我们的研究并不主张为了降低翻修率而额外使用陶瓷头与聚乙烯轴承组合所带来的额外成本。这与研究和主要关节登记处的发现形成对比。
