Emerson Roger H
Texas Center for Joint Replacement, Plano, USA.
Instr Course Lect. 2005;54:221-4.
Two diferent mobile-bearing unicompartmental knee replacement designs have been available since the late 1970s. The primary difference between these two designs is that one has a constrained bearing in a track and the other has a freely moving bearing. Both implants are currently indicated for the treatment of patients with medial unicompartmental osteoarthritis and are available for use in the United States. The benefits of such designs are restoration of normal knee joint kinematics and protection of the polyethylene by reduction of high-contact stresses that occur with nonmobile-bearing designs. Experience has shown that careful patient selection and careful surgical technique both are factors critical to the success of mobile-bearing unicompartmental knee implants. The most important patient selection criteria have proved to be the diagnosis of anteromedial osteoarthritis with a passively correctable varus deformity and intact anterior cruciate ligament. Precise instrumentation is necessary to consistently balance and align a mobile-bearing implant. Ten-year survivorship data for freely mobile-bearing implants are available from multiple centers that show survivorship rates ranging from 85% to 98%, which are comparable to survivorship rates for total knee replacement.
自20世纪70年代末以来，有两种不同的活动平台单髁膝关节置换设计可供使用。这两种设计的主要区别在于，一种在轨道中有约束性衬垫，另一种有自由活动的衬垫。目前这两种植入物都适用于治疗内侧单髁骨关节炎患者，并且在美国都可供使用。此类设计的益处在于恢复正常膝关节运动学，并通过减少非活动平台设计中出现的高接触应力来保护聚乙烯。经验表明，仔细的患者选择和精细的手术技术都是活动平台单髁膝关节植入物成功的关键因素。事实证明，最重要的患者选择标准是诊断为伴有可被动矫正内翻畸形和完整前交叉韧带的前内侧骨关节炎。精确的器械对于持续平衡和对齐活动平台植入物是必要的。多个中心提供了自由活动平台植入物的十年生存率数据，显示生存率在85%至98%之间，这与全膝关节置换的生存率相当。
