Poirier N, Graf P, Dubrana F
Faculty of Medicine, université de Bretagne-Occidentale, 22, avenue Camille-Desmoulins, CS 93837, 29238 Brest cedex 3, France; Department of Orthopaedic Surgery, CHRU de Brest, boulevard Tanguy-Prigent, 29200 Brest, France.
Clinique Pasteur-Lanroze, 32, rue Auguste-Kervern, 29200 Brest, France.
Orthop Traumatol Surg Res. 2015 Jun;101(4 Suppl):S187-92. doi: 10.1016/j.otsr.2015.03.004. Epub 2015 Apr 15.
Mobile-bearing total knee arthroplasty (TKA) implants were developed as an alternative to fixed-bearing implants because of their theoretical advantages related to wear and range of motion. For all that, none of the short-term and medium-term studies published so far have reported a significant clinical improvement related to these mobile bearings. The goal of this study was to compare the outcomes of fixed and mobile bearings in the same type of TKA model after a longer follow-up.
This series initially comprised 100 patients with a mean age of 73 years who were operated by a single surgeon. The patients were randomised to receive either a fixed bearing TKA implant or a mobile one; their outcomes evaluated after a mean of 9 years (7.2-12.2) follow-up. Twenty-two patients died before the final review, 15 were lost to follow-up and 2 were excluded. This resulted in 30 patients with a mobile-bearing knee and 31 with a fixed-bearing knee being available for analysis.
There were no significant clinical differences between the groups receiving a fixed or mobile bearing in terms of the range of motion, subjective outcomes or validated outcomes measured, such as the self-reported Oxford or the IKS. Conversely, there was a significantly higher rate of osteolysis in the fixed-bearing group, but it was not clinically relevant.
This study, which has the longest published follow-up, confirms the results found in the seven randomised studies published up to now: there are no significant differences in the clinical outcomes between fixed-bearing and mobile-bearing inserts of the same TKA model. Although the mobile bearing knees had a better radiographic appearance, this did not translate to better clinical outcomes. In practice, the superiority of mobile bearings is solely theoretical.
Prospective randomised study.
活动平台全膝关节置换术（TKA）植入物作为固定平台植入物的替代方案而开发，因其在磨损和活动范围方面具有理论优势。尽管如此，迄今为止发表的所有短期和中期研究均未报告与这些活动平台相关的显著临床改善。本研究的目的是在更长时间的随访后，比较同一类型TKA模型中固定平台和活动平台的结果。
本系列最初包括100例平均年龄73岁的患者，均由同一位外科医生进行手术。患者被随机分配接受固定平台TKA植入物或活动平台植入物；平均随访9年（7.2 - 12.2年）后评估其结果。22例患者在最终复查前死亡，15例失访，2例被排除。这导致30例接受活动平台膝关节置换的患者和31例接受固定平台膝关节置换的患者可供分析。
在活动范围、主观结果或经过验证的结果（如自我报告的牛津评分或IKS评分）方面，接受固定平台或活动平台的两组之间没有显著的临床差异。相反，固定平台组的骨溶解发生率显著更高，但在临床上并不相关。
本研究拥有已发表研究中最长的随访时间，证实了迄今为止发表的七项随机研究的结果：同一TKA模型的固定平台和活动平台假体在临床结果上没有显著差异。尽管活动平台膝关节的影像学表现更好，但这并未转化为更好的临床结果。在实践中，活动平台的优越性仅仅是理论上的。
证据等级II：前瞻性随机研究。
