Quack G, Rischke B, Bensmann G, Krahl H, Maronna U, Singewald M
G. Quack, Ltd. OA Orthopädische Klinik, Alfried-Krupp-Krkhs. Essen.
Z Orthop Ihre Grenzgeb. 1991 Sep-Oct;129(5):453-9. doi: 10.1055/s-2008-1040272.
Hollow prostheses appear to represent a promising approach for the durable fixation of cementless hip-joint endoprostheses. The goal of the planned development is the design-engineering, quality-assured production and clinical testing of hollow prostheses displaying largest possible interior space and optimized wall thickness. With hollow prostheses the possibility exists for the first time of filling both the interior space of the prosthesis and cavities between the prosthesis bearing and the prosthesis with spongiosa. Theoretical considerations indicate that this should result in early and durable secondary stability. First results from animal experiments show that the canine femora operated on display a stress distribution closely approximating the natural stress distribution in the bone and exhibit the expected ingrowth of spongiosa into the interior space of the hollow prosthesis. The choice of suitable materials and particularly of wall thickness and cross-sectional shape has a decisive bearing on the elastic behaviour of the prosthesis. Compared with a solid prosthesis of the same geometry, a hollow prosthesis exhibits reduced flexural rigidity and hence higher elasticity. The dynamic tests performed on hollow prostheses in line with DIN 58,840 have shown that--given careful design and manufacture as well as effective quality-assurance measures--fatigue failure is not to be expected in the case of hollow prostheses.
空心假体似乎是一种用于非骨水泥型髋关节假体持久固定的有前景的方法。计划开发的目标是设计工程、质量保证生产以及对具有尽可能大的内部空间和优化壁厚的空心假体进行临床测试。有了空心假体，首次有可能用松质骨填充假体的内部空间以及假体承重部分与假体之间的腔隙。理论考虑表明，这应能实现早期且持久的二期稳定性。动物实验的初步结果表明，接受手术的犬股骨显示出的应力分布与骨中的自然应力分布非常接近，并且松质骨向空心假体内部空间的生长符合预期。合适材料的选择，特别是壁厚和横截面形状的选择，对假体的弹性行为具有决定性影响。与相同几何形状的实心假体相比，空心假体的抗弯刚度降低，因此弹性更高。按照DIN 58840对空心假体进行的动态测试表明，在精心设计和制造以及有效的质量保证措施的情况下，空心假体预计不会出现疲劳失效。
