Affatato Saverio, Comitini Saverio, Fosco Matteo, Toni Aldo, Tigani Domenico
Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano, 1/10, 40136, Bologna, Italy.
Unità Operativa Complessa di Ortopedia e Traumatologia, Ospedale Maggiore, Bologna, Italy.
Int Orthop. 2016 Nov;40(11):2261-2269. doi: 10.1007/s00264-016-3141-3. Epub 2016 Feb 29.
Since 1979 the number of patients treated with femoral stems has continued to grow, as well as the number of stems with features similar to the Zweymüller prosthesis produced by different companies. Identification can be problematic in case requiring revision. In the present paper, we present an overview of morphometric differences between the different stem designs, which can be useful for radiologic identification in revision cases.
By doing some research on the Internet of specialized sites and worldwide literature, we searched for all femoral stems agreeing with Zweymüller principles (cementless, straight, tapered, rectangular cross-sectioned femoral stems).
We found 26 different stems from different companies producing or having produced in the past the Zweymüller-type femoral stems for hip prosthesis.
Accurate preoperative identification of the Zweymüller femoral stem type may be of critical importance to eventual outcomes following revision surgery. Each manufacturer has different instruments specific to the removal of their primary implants, and ensuring they are available can simplify the revision procedure significantly. Exact pre-operative planning is also necessary for selecting the correct ball head in cases where a stem is well-fixed and can be left in situ. The commonly used notation "Eurocone 12/14" provides no information about the actual taper angle. Whenever the stem is left in situ, the exact specifications of the taper must therefore be obtained from the manufacturer in order to use a metal sleeve that precisely fits it and the ball head. Failure to do so may result in severe complications, such as metallosis. In cases where it is not possible to identify the taper angle, the surgeon may even consider removal of the stem, though this significantly increases the surgical procedure's invasiveness. Only a single, uniform standard taper, such as that offered until 1994 by CeramTec, can solve these issues in the future.
The survival rate of the Zweymüller stems after ten years was 96 % and the complication rate was very low. Pre-operative identification of the femoral implant is of considerable importance for planning and correctly implementing revision procedures.
自1979年以来，接受股骨柄治疗的患者数量持续增长，不同公司生产的具有与Zweymüller假体相似特征的股骨柄数量也在增加。在需要翻修的情况下，识别可能会有问题。在本文中，我们概述了不同股骨柄设计之间的形态测量差异，这对于翻修病例的放射学识别可能是有用的。
通过在专业网站互联网和全球文献上进行一些研究，我们搜索了所有符合Zweymüller原则的股骨柄（非骨水泥型、直的、锥形、矩形横截面股骨柄）。
我们发现了来自不同公司的26种不同的股骨柄，这些公司目前或过去生产用于髋关节假体的Zweymüller型股骨柄。
准确术前识别Zweymüller股骨柄类型对于翻修手术后的最终结果可能至关重要。每个制造商都有特定于移除其初次植入物的不同器械，确保这些器械可用可以显著简化翻修程序。在股骨柄固定良好且可以留在原位的情况下，精确的术前规划对于选择正确的球头也很必要。常用的标注“Eurocone 12/14”没有提供关于实际锥角的信息。因此，每当股骨柄留在原位时，必须从制造商处获得锥度的确切规格，以便使用精确适配它和球头的金属套筒。否则可能会导致严重并发症，如金属沉着症。在无法识别锥角的情况下，外科医生甚至可能考虑移除股骨柄，尽管这会显著增加手术的侵入性。只有单一的、统一的标准锥度，例如1994年以前CeramTec提供的那种，才能在未来解决这些问题。
Zweymüller股骨柄十年后的生存率为96%，并发症发生率非常低。股骨植入物的术前识别对于规划和正确实施翻修程序相当重要。
