College of Medicine and Public Health Flinders University, Bedford Park, SA 5042, Australia.
Department of Orthopaedic Surgery and Trauma Flinders Medical Centre Bedford Park, SA 5042, Australia.
Knee. 2021 Dec;33:243-251. doi: 10.1016/j.knee.2021.09.012. Epub 2021 Nov 1.
An attribute that may influence knee replacement survivorship is tibial polyethylene (PE) insert thickness. Previous studies have suggested thin polyethylene made from ultra-high molecular weight polyethylene (UHMWPE) leads to higher rates of revision surgery. This study aimed to determine if modern polyethylene thickness is associated with altered survivorship of primary total knee arthroplasty (TKA) procedures.
A retrospective analysis of data from Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) was done on well performing total knee arthroplasty prostheses used in Australia from 1999-2018. Six of the best performing minimally stabilized prostheses were examined and categorized into three PE thickness subgroups: A (≤10 mm), B (11-14 mm) and C (≥15 mm). There were 185,539 TKA procedures, of which 64.3% (n = 119,382) were ≤ 10 mm, 33.5% (n = 62,173) 11-14 mm, and 2.2% (n = 3984) ≥ 15 mm. Differences in revision rates were analysed for all causes, including loosening, wear, and instability.
At 14 years, respective cumulative point revision (CPR) was A: 4.8, B: 4.2 and C: 6.0. The thickest polyethylene group (≥15 mm) had a higher rate of revision for any reason compared to both 11-14 mm and ≤ 10 mm groups. When non-XLPE was analysed the ≤ 10 mm group had higher rates of revision compared to the 11-14 mm group, but this difference was not seen with XLPE.
Higher rates of revision were seen overall in the thicker PE group (≥15 mm). This group also had higher rates of revision for loosening, instability, and infection. The use of a thicker insert may be a sign of surgical complexity, but is associated with increased revision.
可能影响膝关节置换存活率的一个因素是胫骨聚乙烯（PE）插入物的厚度。先前的研究表明，由超高分子量聚乙烯（UHMWPE）制成的薄聚乙烯会导致更高的翻修手术率。本研究旨在确定现代聚乙烯厚度是否与澳大利亚使用的原发性全膝关节置换术（TKA）程序的存活率改变有关。
对澳大利亚骨科协会国家关节置换登记处（AOANJRR）的数据进行了回顾性分析，这些数据来自澳大利亚 1999 年至 2018 年期间使用的表现良好的全膝关节置换假体。检查了六个表现最佳的最小稳定假体，并将其分为三个 PE 厚度亚组：A（≤10mm）、B（11-14mm）和 C（≥15mm）。共有 185539 例 TKA 手术，其中 64.3%（n=119382）为≤10mm，33.5%（n=62173）为 11-14mm，2.2%（n=3984）为≥15mm。分析了所有原因的翻修率，包括松动、磨损和不稳定。
在 14 年时，各自的累积点修订率（CPR）分别为 A：4.8、B：4.2 和 C：6.0。最厚的聚乙烯组（≥15mm）的翻修率高于 11-14mm 和≤10mm 组。当分析非 XLPE 时，≤10mm 组的翻修率高于 11-14mm 组，但在 XLPE 中则没有这种差异。
总体而言，在较厚的 PE 组（≥15mm）中观察到更高的翻修率。该组的松动、不稳定和感染翻修率也较高。使用较厚的插入物可能是手术复杂性的标志，但与翻修率增加有关。
