Lacko Marek, Schreierová Daniela
Department of Orthopedics and Traumatology of Locomotors Apparatus, Medical Faculty of Pavol Jozef Safárik University and University Hospital of L. Pasteur, Kosice, Slovakia.
Eklem Hastalik Cerrahisi. 2019 Aug;30(2):70-8. doi: 10.5606/ehc.2019.62830.
This study aims to determine whether there is a difference in the rate of survival and risk of revision for mobile-bearing (MB) compared with fixed-bearing (FB) total knee replacements (TKRs).
This prospective observational study included 1,571 cemented non-posterior-stabilized TKRs without patellar resurfacing with the subsequent revision surgery in 63 patients (23 males, 40 females; mean age 69.7 years; range, 46.5 to 85.5 years). The group of FB TKRs consisted of 756 non-revised and 31 revised implants. The group of MB TKRs included 752 non-revised and 32 revised knees. We determined the survival rate of TKR with Kaplan-Meier method and the relative risk (RR) of the revision in relation to the type of the insert. The analysis of the RR was divided into subgroups based on the time to revision and the reason for revision.
No significant difference was found between FB and MB TKRs regarding the cumulative survival rate and the RR of total revision for any reasons. In the subgroup of early revisions for any reason, 2.22-fold increased risk of revision was found in the MB (p=0.02). The risk of late revisions for any reason in MB was lower than the risk in FB (RR 0.27; p=0.009). Higher risk of revision for instability was found in the subgroup of early revisions in MB (RR 23.8; p=0.03). MB was associated with significantly lower risk of total (RR 0.46; p=0.049) and late revisions for aseptic loosening (RR 0.14; p=0.008).
No differences were found in the cumulative survival rates between MB and FB TKRs. MB TKRs were associated with a lower risk of revision due to aseptic loosening in comparison with FB TKRs. MB inserts represented a significant risk factor only for early revisions due to instability.
本研究旨在确定活动平台（MB）与固定平台（FB）全膝关节置换术（TKR）的生存率和翻修风险是否存在差异。
这项前瞻性观察性研究纳入了1571例无髌骨表面置换的骨水泥型非后稳定型TKR，其中63例患者（23例男性，40例女性；平均年龄69.7岁；范围46.5至85.5岁）接受了后续翻修手术。FB TKR组包括756例未翻修和31例翻修的植入物。MB TKR组包括752例未翻修和32例翻修的膝关节。我们采用Kaplan-Meier法确定TKR的生存率，并根据植入物类型确定翻修的相对风险（RR）。RR分析根据翻修时间和翻修原因分为亚组。
FB和MB TKR在累积生存率和任何原因导致的全翻修RR方面均未发现显著差异。在任何原因导致的早期翻修亚组中，MB的翻修风险增加了2.22倍（p = 0.02）。MB中任何原因导致的晚期翻修风险低于FB（RR 0.27；p = 0.009）。在MB的早期翻修亚组中，发现不稳定导致的翻修风险更高（RR 23.8；p = 0.03）。MB与全翻修（RR 0.46；p = 0.049）和无菌性松动导致的晚期翻修风险显著降低相关（RR 0.14；p = 0.008）。
MB和FB TKR的累积生存率无差异。与FB TKR相比，MB TKR因无菌性松动导致的翻修风险较低。MB植入物仅在因不稳定导致的早期翻修中是一个显著的风险因素。
