Department of Orthopaedic Surgery, University of Minnesota Medical Center, 2450 Riverside Avenue South, R200, Minneapolis, MN 55454, USA.
J Bone Joint Surg Am. 2010 Sep;92 Suppl 1 Pt 2:240-9. doi: 10.2106/JBJS.J.00157.
Proponents of mobile-bearing total knee arthroplasty believe that it has potential advantages over a fixed-bearing design in terms of diminished wear and improved motion and/or function, but these advantages have not been demonstrated in a randomized clinical comparison to our knowledge. We conducted a patient-blinded, prospective, randomized clinical trial to compare mobile-bearing and fixed-bearing cruciate-substituting total knee arthroplasties of the same design.
Patients between the ages of sixty and eighty-five years were prospectively randomized to receive a cruciate-substituting rotating-platform design or a fixed-bearing design with an all-polyethylene tibial component. There were no significant differences in the demographic characteristics (mean age, 72.2 years; mean American Society of Anesthesiologists score, 2.7; mean body mass index, 31.8 kg/m2) or preoperative clinical or radiographic measures between the groups. Routine clinical and radiographic follow-up measures included the Knee Society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-36 (SF-36) outcome measures.
The results of 312 arthroplasties (136 with an all-polyethylene tibial component and 176 rotating-platform designs) in 273 patients were analyzed at a minimum of two years (mean, forty-two months) postoperatively. Although there was significant improvement in both groups, there was no significant difference between the groups with regard to the mean postoperative range of motion (110.9° and 109.1°, respectively; p = 0.21), the mean KSS clinical score (90.4 and 88.2 points; p = 0.168), or the mean KSS pain score (44.9 and 43.1 points; p = 0.108) at this follow-up point. There were ten revisions: seven because of infection, one because of patellar fracture, one because of instability, and one because of aseptic loosening.
The two designs functioned equivalently at the time of early follow-up in this low-to-moderate-demand patient group. The rotating-platform design had no significant clinical advantage over the design with the all-polyethylene tibial component.
提倡使用带活动衬垫的全膝关节置换术的人认为，与固定衬垫设计相比，它在减少磨损和改善运动和/或功能方面具有潜在优势，但据我们所知，这些优势尚未在与随机临床比较中得到证明。我们进行了一项患者盲法、前瞻性、随机临床试验，以比较相同设计的带活动衬垫和固定衬垫的十字韧带替代全膝关节置换术。
年龄在 60 至 85 岁之间的患者前瞻性随机接受十字韧带替代旋转平台设计或全聚乙烯胫骨组件的固定衬垫设计。两组在人口统计学特征（平均年龄 72.2 岁；平均美国麻醉医师协会评分 2.7；平均体重指数 31.8kg/m2）或术前临床或影像学测量方面无显著差异。常规临床和影像学随访测量包括膝关节协会评分（KSS）、西安大略和麦克马斯特大学骨关节炎指数（WOMAC）和 36 项简短健康调查（SF-36）结果测量。
在至少两年（平均 42 个月）的术后随访中，对 273 名患者的 312 例膝关节置换术（136 例全聚乙烯胫骨组件和 176 例旋转平台设计）进行了结果分析。尽管两组都有显著改善，但两组之间的平均术后活动范围（分别为 110.9°和 109.1°；p=0.21）、平均 KSS 临床评分（90.4 和 88.2 分；p=0.168）或平均 KSS 疼痛评分（44.9 和 43.1 分；p=0.108）均无显著差异。共有 10 例进行了翻修：7 例因感染，1 例因髌骨骨折，1 例因不稳定，1 例因无菌性松动。
在这个低至中度需求的患者群体中，在早期随访时，两种设计的功能相当。旋转平台设计与全聚乙烯胫骨组件设计相比，没有明显的临床优势。
