Maslaris Alexander, Layher Frank, Brinkmann Olaf, Bungartz Matthias, Zippelius Timo, Matziolis Georg
Department of Orthopedics, Friedrich-Schiller-University of Jena, Campus Eisenberg, Klosterlausnitzer Straße 81, 07607, Eisenberg, Germany.
Department of Orthopedics, Laboratory of Biomechanics, Friedrich-Schiller-University of Jena, Campus Eisenberg, Klosterlausnitzer Straße 81, 07607, Eisenberg, Germany.
Arch Orthop Trauma Surg. 2018 Dec;138(12):1747-1754. doi: 10.1007/s00402-018-3053-3. Epub 2018 Oct 26.
According to literature, more than 30% of revised knee arthroplasties will require at least one re-revision. Practical experience has shown that there are considerable product-specific differences in the explantability of cemented long-stem prostheses. In the registers of successful implants, stem geometry varies considerably between the manufacturers. However, comparative data on explantability of the respective stems are missing. Objective of the present study was to identify a correlation between the geometry of a smooth cemented long stem and the necessary explantation energy required until failure of the implant-cement interface occurs.
Eight cemented stems with different conical profile angles (0°-3°) were explanted in a reproducible biomechanical setup each six times to evaluate the correlation between the stem design and the required explantation energy.
The average explantation energy was highest in the case of the cylindrical stem, at 18.1 ± 3.6 J. At a cone angle of 0.25°, it was just 12.1 ± 2.1 J (p < 0.001) and dropped beyond 0.5° to an average of 5.7 ± 1.8 J (p < 0.001). Between 0.5° and 3°, no significant difference in the required extraction energy was observed.
Whereas smooth conical stems can mostly be removed easily, an early decision in favour of osteotomy or fenestration can be taken in the case of cylindrical cemented stems.
根据文献，超过30%的翻修膝关节置换术将需要至少一次再次翻修。实践经验表明，骨水泥固定长柄假体的取出难易程度存在显著的产品特异性差异。在成功植入物的登记记录中，不同制造商的柄部几何形状差异很大。然而，关于各个柄部取出难易程度的比较数据却缺失。本研究的目的是确定光滑骨水泥固定长柄的几何形状与植入物 - 骨水泥界面失效前所需的取出能量之间的相关性。
八个具有不同圆锥轮廓角（0° - 3°）的骨水泥柄在可重复的生物力学装置中每次取出六次，以评估柄部设计与所需取出能量之间的相关性。
圆柱形柄的平均取出能量最高，为18.1 ± 3.6焦耳。在圆锥角为0.25°时，仅为12.1 ± 2.1焦耳（p < 0.001），超过0.5°后降至平均5.7 ± 1.8焦耳（p < 0.001）。在0.5°至3°之间，未观察到所需取出能量的显著差异。
虽然光滑的圆锥形柄大多可以轻松取出，但对于圆柱形骨水泥柄，可尽早决定采用截骨术或开窗术。
