Morpho functional interbone parameters in supine versus standing position – Comparison of CT and EOS Alignment

EPiC series in health sciences, vol. 7, pp. 63–55

Abstract

Morpho-functional interbone parameters of the knee are often used in clinical practice to assess the functional anatomy of the individual patient. Respective parameters, such as the TT-TG distance, are regularly measured manually on CT or MRI images. To overcome this time-consuming process, an automated framework for knee morphological analysis was previously presented by our group. A relevant remaining limitation, however, is the imaging performed in supine and not in an active, weight-bearing position, which was addressed in this study. Data from 7 patients (14 knees) scheduled for total hip arthroplasty were used for this study. After segmentation, the CT-derived bone surface models were matched to the EOS images based on landmarks, with manual control and optional correction. Subsequently, the automated framework for morphological analysis was applied. A statistically significant difference in mean was found for the joint rotation. The other mean deviations were not statistically significant and below the parameters’ standard deviation, whereas the absolute deviations were higher. This fact highlights the relevance of inter-individual differences in supine versus standing interbone parameter measurements. In general, large discrepancies regarding the changes in interbone parameter measurements from supine to standing position were found in the literature. The results of this study are plausible with regard to theoretical biomechanical relations. Overall, the study motivates an interbone parameter assessment in a standardized, active weight-bearing position. With further automation in data pre-processing, the workflow could be applied to large databases and hence be used to define reference ranges of interbone parameters in various poses.

Authors 5

1. Sonja A. G. A. Grothues Aachen Chair of Medical Engineering

   RWTH Aachen University

   Affiliation as printed

   Chair of Medical Engineering , Helmholtz Institute for Biomedical Engineering , RWTH Aachen University , Aachen , 52074 , Germany

2. Leonie Stellmann Aachen Chair of Medical Engineering

   RWTH Aachen University

   Affiliation as printed

   Chair of Medical Engineering , Helmholtz Institute for Biomedical Engineering , RWTH Aachen University , Aachen , 52074 , Germany

3. Luisa Berger Aachen Chair of Medical Engineering

   RWTH Aachen University

   Affiliation as printed

   Chair of Medical Engineering , Helmholtz Institute for Biomedical Engineering , RWTH Aachen University , Aachen , 52074 , Germany

4. Kunihiko Tokunaga

   Kameda Daiichi Hospital

   Affiliation as printed

   Niigata Hip Joint Center , Kameda Daiichi Hospital , Niigata City , 950-0165 Japan

5. Klaus Radermacher Aachen Chair of Medical Engineering

   RWTH Aachen University

   Affiliation as printed

   Chair of Medical Engineering , Helmholtz Institute for Biomedical Engineering , RWTH Aachen University , Aachen , 52074 , Germany