Acharya A, Timperley A J, Lee A J C
Warrington and Halton Hospitals NHS Foundation Trust, Warrington, UK.
Proc Inst Mech Eng H. 2011 Jan;225(1):86-93. doi: 10.1243/09544119JEIM804.
The most common cause of failure of a total hip replacement is aseptic loosening of an implant. In a number of cases, the cement-bone interface of at least one component is not compromised. In cases of aseptic cup loosening, removal of a well-fixed femoral stem may be undertaken to facilitate exposure of the acetabulum for cup revision, and the surgeon may choose to leave the functional cement-bone interfaces in the femur undisturbed. After cup revision, new cement is pressurized within the old cement mantle and a stem is cemented into this 'old-new cement' composite. Retaining the old cement mantle is an attractive option as it reduces the duration of surgery, minimizes bleeding, and preserves the bone stock. Excellent results have been shown with this technique of 'in-cement femoral revision' using a double-tapered polished stem. While considerable literature is available on the short- and long-term properties of PMMA bone cement, very little is known about the mechanical properties of old-new composite cement specimens where the old cement is more than a few days old. This paper tests the properties of such old-new composite specimens where the 'old' cement is aged between 3.3 and 17.7 years, better reflecting clinical situations.
全髋关节置换失败最常见的原因是植入物的无菌性松动。在许多情况下，至少一个组件的骨水泥-骨界面并未受损。在无菌性髋臼杯松动的情况下，可以移除固定良好的股骨干以方便髋臼杯翻修时暴露髋臼，并且外科医生可能会选择不干扰股骨中功能良好的骨水泥-骨界面。髋臼杯翻修后，新骨水泥在旧骨水泥壳内加压，然后将一个柄部用骨水泥固定到这个“新旧骨水泥”复合体中。保留旧骨水泥壳是一个有吸引力的选择，因为它缩短了手术时间，减少了出血，并保留了骨量。使用双锥形抛光柄部的“骨水泥内股骨翻修”技术已显示出优异的效果。虽然有大量关于聚甲基丙烯酸甲酯（PMMA）骨水泥短期和长期性能的文献，但对于旧骨水泥超过几天的新旧复合骨水泥标本（试件）的力学性能却知之甚少。本文测试了“旧”骨水泥老化时间在3.3至17.7年之间的此类新旧复合标本（试件）的性能，能更好地反映临床情况。
