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Updated: Jun 4, 2026
Four-Dimensional CT Analysis Using Sequential 3D-3D Registration
Published on: November 23, 2019
Sensitivity analysis of hip joint centre estimation based on three-dimensional CT scans
W Bartels1, J Vander Sloten, I Jonkers
1Department of Mechanical Engineering, Katholieke Universiteit Leuven, Leuven, Belgium. ward.bartels@mech.kuleuven.be
Insights
Determining the hip joint centre (HJC) using 3D femoral models is reliable for healthy hips. Image selection thresholds minimally impact HJC calculations, ensuring valid results for morphological analysis.
Area of Science:
- Orthopedic surgery
- Biomechanical engineering
- Medical imaging analysis
Background:
- Accurate hip joint centre (HJC) determination is crucial for femur morphological analysis.
- Current HJC methods rely on 3D femoral head models from medical images, but image selection can introduce variability.
- The influence of image segmentation on HJC calculation accuracy requires investigation.
Purpose of the Study:
- To evaluate the impact of image segmentation thresholds on three HJC calculation methods, including a novel approach.
- To assess the sensitivity of HJC results to variations in the selected femoral head portion.
- To compare the performance of different HJC calculation methods, particularly in cases of hip deformity.
Main Methods:
- Utilized cadaver CT images to isolate femoral heads using distance thresholds between femur and acetabulum models.
- Quantified the sensitivity of HJC calculations to varying segmentation thresholds.
- Compared a newly developed HJC method against two existing techniques.
Main Results:
- For healthy hips and thresholds between 6-9 mm, HJC differences were <1 mm, showing method insensitivity.
- Higher thresholds led to inaccuracies due to the fovea capitis femoris affecting HJC.
- The novel method demonstrated superior performance in two cases of deformed hips.
Conclusions:
- Existing and novel HJC calculation methods yield valid results for normal hips within specific segmentation parameters.
- The fovea capitis femoris can disrupt HJC accuracy at higher segmentation thresholds.
- The introduced method shows promise for HJC determination in hips with deformities.
Abstract:
In morphological analysis of the femur, the hip joint centre (HJC) is generally determined using a 3D model of the femoral head based on medical images. However, the portion of the image selected to represent the femoral head may influence the HJC. We determined if this influence invalidates the results of three HJC calculation methods, one of which we introduce here. To isolate femoral heads in cadaver CT images, thresholds were applied to the distance between femur and acetabulum models. The sensitivity of the HJC to these thresholds and the differences between methods were quantified. For thresholds between 6 and 9 mm and healthy hips, differences between methods were below 1 mm and all methods were insensitive to threshold changes. For higher thresholds, the fovea capitis femoris disturbed the HJC. In two deformed hips, the new method performed superiorly. We conclude that for normal hips all methods produce valid results.
