College of Medicine, University of Ulsan, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, 05505 Seoul, Republic of Korea.
Department of Orthopedic Surgery, Unjeong Inbone Hospital, 31, Cheongam-ro 17-gil, Paju-si, 10892 Gyeonggi-do, Republic of Korea.
Orthop Traumatol Surg Res. 2023 Dec;109(8):103644. doi: 10.1016/j.otsr.2023.103644. Epub 2023 Jun 16.
As life expectancy has improved, the potential number of revision candidates is also expected to increase among patients who have undergone a total knee arthroplasty (TKA). The longevity of modern posterior stabilized knee prostheses after 20 years of use has not been well documented, especially in Asian populations that require a deeper flexion range due to a floor-based lifestyle.
Firstly, the implant longevity regarding mechanical failures such as aseptic loosening and polyethylene (PE) wear would vary over a longer follow-up depending on the age groups; and secondly there would be unique risk factors for revision surgery in an Asian TKA cohort.
We conducted this age-stratified survival analysis in a consecutive series of 368 NexGen Legacy Posterior Stabilized (LPS) TKAs performed by a single surgeon. These cases were divided into four age groups (< 60 years, early 60s, late 60s, and ≥ 70 years). The implant longevity against aseptic mechanical failures was calculated using the Kaplan-Meier method. The revision surgery risk was evaluated using postoperative factors including a deep flexion capability (> 135̊), and postoperative mechanical alignments.
Overall survivorship was significantly lower in the youngest groups than other groups (Log-rank test, p=0.001). The cumulative 20-year implant longevity was more than 95% in the two oldest groups, but less than 60% in the youngest group. It was notable that the post-TKA implant longevity was not apparent up to 10 years between the age groups (p=0.073∼0.458). Aseptic loosening was observed with an earlier onset (3.1 to 18.9 years) trend than PE wear (9.8∼17.9 years), with most cases arising in the youngest groups. Flexion limitation and varus alignment were significant risks to aseptic loosening and PE wear (Cox proportional hazard regression: p=0.001 and 0.045, respectively).
A younger age (< 60 years), inability of postoperative deep flexion, and varus alignment were significant risk factors for aseptic loosening and PE wear after modern PS design in this Asian cohort. The difference in postoperative longevity affected by these factors was not obvious during the first 10 years but emerged over a second decade.
III; retrospective cohort study.
随着预期寿命的提高，接受全膝关节置换术 (TKA) 的患者中需要进行翻修的候选人数预计也会增加。现代后稳定型膝关节假体在使用 20 年后的长期寿命尚未得到很好的记录，尤其是在因生活方式以地板为基础而需要更大屈膝范围的亚洲人群中。
首先，在更长的随访时间内，机械故障（如无菌性松动和聚乙烯 (PE) 磨损）的植入物寿命会因年龄组而异；其次，在亚洲 TKA 队列中，翻修手术存在独特的危险因素。
我们对一位外科医生连续进行的 368 例 NexGen Legacy 后稳定型 (LPS) TKA 进行了分层生存分析。这些病例分为四个年龄组（<60 岁、60 岁出头、60 岁后期和≥70 岁）。使用 Kaplan-Meier 方法计算无菌机械故障的植入物寿命。使用术后因素（包括>135°的深度屈曲能力和术后机械对线）评估翻修手术风险。
在最年轻的组中，总体生存率明显低于其他组（对数秩检验，p=0.001）。最年长的两组中，20 年累计植入物生存率均超过 95%，但最年轻的组中则不到 60%。值得注意的是，在年龄组之间，直到 10 年为止，术后植入物的寿命并没有明显的区别（p=0.073∼0.458）。无菌性松动的发生时间早于 PE 磨损（3.1 至 18.9 年），而 PE 磨损的发生时间较晚（9.8∼17.9 年），且大多数病例发生在最年轻的组中。术后屈曲受限和内翻对线是无菌性松动和 PE 磨损的显著危险因素（Cox 比例风险回归：p=0.001 和 0.045）。
在这个亚洲队列中，对于现代 PS 设计，年龄较小（<60 岁）、术后无法进行深度屈曲以及内翻对线是无菌性松动和 PE 磨损的显著危险因素。在最初的 10 年内，这些因素对术后寿命的影响并不明显，但在第二个十年中显现出来。
III；回顾性队列研究。
