Related Experiment Video
Updated: Sep 3, 2025
Four-Dimensional CT Analysis Using Sequential 3D-3D Registration
Published on: November 23, 2019
The "true" acetabular anteversion angle (AV angle): 2D CT versus 3D model
Kira A Barlow1, Zdzislaw Krol2, Pawel Skadlubowicz3
1Pediatric Orthopedic Department, University Children's Hospital Basel (UKBB), Spitalstrasse 33, CH-4056, Basel, Switzerland. k.oesterwind@yahoo.de.
Introduction:
Different factors can lead to inconsistencies in measurement for the acetabular version using 2D axial CT-cuts. We have defined a "true" anteversion angle (AV angle) in the physiological position of the pelvis in 3D with the largest European population measured to our knowledge.
Material And Methods:
We analyzed 258 hemipelvises and created 3D models. We compared the results of our AV angle 3D method with the cross-sectional cuts of the same acetabula. We included factors like side, sex, body mass index, and patient positioning.
Results:
Overall, the mean (SD) AV angle was 16.1 (5.9)° as measured with the 3D method and 22.0 (6.0)° as measured with the 2D method (p < 0.0001). Measured with both the 3D and the 2D method, the AV angle was significantly larger in female than in male individuals (p < 0.0001). In the 2D method, the AV angle estimation was influenced by the pelvic tilt.
Conclusion:
We propose a more accurate method for the measurement of the AV angle of the acetabulum in a 3D model that is not influenced by patient positioning or pelvic tilt. We provide a computational model that will facilitate operative decisions and improve preoperative planning. We confirm that 3D measurement should be the gold standard in measuring the acetabular anteversion.
