Starker M, Hanusek S, Rittmeister M, Thoma W
Rheumaorthopädische Abteilung, Orthopädischen Universitätsklinik, Stiftung Friedrichsheim, Frankfurt/Main.
Z Orthop Ihre Grenzgeb. 1998 Sep-Oct;136(5):420-7. doi: 10.1055/s-2008-1053678.
Several CT-procedures exist to determine rotational variances of the femur. However, solely on the basis of few CT-scans and without a three-dimensional reconstruction of the femur, it is impossible to define the exact course of the femoral neck axis. Looking for determination of the exact course of the femoral neck axis, auxiliary constructions need to be called upon. Aim of the study was to validate several existing CT-procedures and analyse their respective error rates.
Fourty-five femora were CT-scanned and subsequently reconstructed three-dimensionally in this study. Femoral anteversion was measured using three different CT-methods in each of these femora and in addition, the respective anatomical anteversion was determined in each femur. In order to test the reliability of such methods, flexion of the femora around the center of the femoral head as well as a varus deformity of the longitudinal axis of the femora were simulated and anteversion measurements were repeated in such simulated positions. Results were statistically analysed using SPSS.
All tested CT-methods, when compared to the anatomical anteversion of a femur, showed differing anteversion-angles with statistical significance (p < 0.001). Equally, the results of the individual methods tested differed with significance. Due to a high correlation with the anatomical anteversion, all methods examined expressed trend of anteversion. Under simulated hip flexion, the "Ulmer Method" produced different values with statistical significance which were, however, without correlation to anteversion values in joint extension. With statistical significance, the "Essener Method" produced different anteversion values when the longitudinal axis of the femur was modified; however, these values highly correlated to anteversion values of femora with unchanged longitudinal axis.
Our results lead us to conclude that the "Essener Method" being an interindividual method and independent from positioning, is the most suitable procedure as it allows for the correction of errors with respect to anatomical anteversion.
有多种CT检查方法可用于确定股骨的旋转差异。然而，仅基于少量CT扫描且未对股骨进行三维重建的情况下，无法明确股骨颈轴线的确切走向。为了确定股骨颈轴线的确切走向，需要借助辅助结构。本研究的目的是验证几种现有的CT检查方法并分析它们各自的误差率。
本研究对45个股骨进行了CT扫描，随后进行三维重建。在每个股骨上使用三种不同的CT方法测量股骨前倾角，此外，还确定了每个股骨的相应解剖学前倾角。为了测试这些方法的可靠性，模拟了股骨围绕股骨头中心的屈曲以及股骨纵轴的内翻畸形，并在这些模拟位置重复进行前倾角测量。使用SPSS对结果进行统计学分析。
与股骨的解剖学前倾角相比，所有测试的CT方法均显示出具有统计学意义的不同前倾角（p < 0.001）。同样，所测试的各个方法的结果也存在显著差异。由于与解剖学前倾角高度相关，所有检查的方法均表现出前倾角趋势。在模拟髋关节屈曲时，“乌尔姆方法”产生了具有统计学意义的不同值，然而，这些值与关节伸展时的前倾角值无关。具有统计学意义的是，当股骨纵轴改变时，“埃森纳方法”产生了不同的前倾角值；然而，这些值与纵轴未改变的股骨的前倾角值高度相关。
我们的结果使我们得出结论，“埃森纳方法”作为一种个体间方法且不受定位影响，是最合适的方法，因为它能够校正相对于解剖学前倾角的误差。
