Department of Orthopaedics, Leiden University Medical Center, Postal Code J11R, PO Box 9600, 2300 RC Leiden, The Netherlands.
Clin Orthop Relat Res. 2012 Dec;470(12):3549-59. doi: 10.1007/s11999-012-2582-2. Epub 2012 Sep 13.
Less than 1% of all primary TKAs are performed with an all-polyethylene tibial component, although recent studies indicate all-polyethylene tibial components are equal to or better than metal-backed ones.
QUESTIONS/PURPOSES: We asked whether the metal-backed tibial component was clinically superior to the all-polyethylene tibial component in primary TKAs regarding revision rates and clinical functioning, and which modifying variables affected the revision rate.
We systematically reviewed the literature for clinical studies comparing all-polyethylene and metal-backed tibial components used in primary TKAs in terms of revision rates, clinical scores, and radiologic parameters including radiostereometric analysis (RSA). Meta-regression techniques were used to explore factors modifying the observed effect. Our search yielded 1557 unique references of which 26 articles were included, comprising more than 12,500 TKAs with 231 revisions for any reason.
Meta-analysis showed no differences between the all-polyethylene and metal-backed components except for higher migration of the metal-backed components. Meta-regression showed strong evidence that the all-polyethylene design has improved with time compared with the metal-backed design.
The all-polyethylene components were equivalent to metal-backed components regarding revision rates and clinical scores. The all-polyethylene components had better fixation (RSA) than the metal-backed components. The belief that metal-backed components are better than all-polyethylene ones seems to be based on studies from earlier TKAs. This might no longer be true for modern TKAs.
Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
尽管最近的研究表明全聚乙烯胫骨组件与金属背衬胫骨组件一样或更好，但所有初次 TKA 中只有不到 1% 使用全聚乙烯胫骨组件。
问题/目的：我们想知道在初次 TKA 中，金属背衬胫骨组件在翻修率和临床功能方面是否优于全聚乙烯胫骨组件，以及哪些修正变量会影响翻修率。
我们系统地回顾了比较初次 TKA 中使用全聚乙烯和金属背衬胫骨组件的临床研究文献，评估了翻修率、临床评分以及包括放射立体测量分析（RSA）在内的放射学参数。我们使用荟萃回归技术来探索影响观察效果的修正因素。我们的检索结果产生了 1557 个独特的参考文献，其中 26 篇文章被纳入，包括超过 12500 例 TKA，其中有 231 例因任何原因进行了翻修。
荟萃分析显示，除了金属背衬组件的迁移率较高外，全聚乙烯和金属背衬组件之间没有差异。荟萃回归显示，与金属背衬设计相比，全聚乙烯设计随着时间的推移得到了显著改善。
在翻修率和临床评分方面，全聚乙烯组件与金属背衬组件相当。全聚乙烯组件的固定（RSA）比金属背衬组件更好。金属背衬组件优于全聚乙烯组件的观点似乎基于早期 TKA 的研究。对于现代 TKA，这种情况可能不再成立。
II 级，治疗性研究。有关证据等级的完整描述，请参见作者指南。
