Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Imaging process flow chart shows how the imaging and motion tracking data were used for calibration, acquiring patient images, and reconstructing the patient’s pelvis and acetabular cup orientation. The multiplanar imaging setup is based on a previously published method [] modified to account for translations of the C-arm gantry with respect to the floor.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Biplanar radiographs of three motion tracking markers were segmented to reconstruct the 3D positions of the centers of the LED emitters of the markers (A, B, and C). This information was used to find the transformation matrix between the coordinate systems of the gantry and the camera tracking system.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Segmenting the pelvis bony landmarks and the acetabular cup. The numbers on the radiographs correspond with the X-ray beams in Fig. . The right and left anterior superior iliac spine (RASIS and LASIS), and right and left pubic tubercle (RPT and LPT), and socket shell were reconstructed each through two radiographic views. The orientation of the acetabular cup was calculated based on fitting an ellipse to the elliptical projection of the cup opening.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Reconstruction of the cup orientation by analyzing the geometry of its elliptical projection. Knowing the 3D positions of the X-ray source (S) and the quadrants of the elliptical fit to the projection (Q1 to Q4), the orientation of the cup (n) was determined through a minimization function that placed P1 to P4 points on a circular perimeter tangent to the projection cone O-Q1Q2Q3Q4.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Graphical output of the Joint3D software shows the calculated values of the operative anterversion (left) and inclination (right). The graphical view also overlays the digitized references to visually demonstrate the differences in the reconstruction of the individual landmarks and pelvic and acetabular cup in comparison to the reference measures.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Segmenting the pelvis bony landmarks on X-ray images from a cadaveric pelvis. The right and left anterior superior iliac spine (RASIS and LASIS), and right and left pubic tubercle (RPT and LPT). Because of soft tissue blocking it was more challenging to identify the bony landmarks. To help registration for each landmark, the X-ray on which the landmark was more discernible (e.g., image 2 for LASIS) was used as the primary image for registering the in-plane location, and the second image (e.g., image 1 for LASIS) was used to determine the depth of the landmark with respect to the first.

Date of download: 10/16/2017 Copyright © ASME. All rights reserved. From: A Multiplanar Radiography Method for Assessing Cup Orientation in Total Hip Arthroplasty J Biomech Eng. 2012;134(10):101008-101008-10. doi:10.1115/1.4007664 Figure Legend: Simulation results demonstrate the effects of uncertainties in radiographic reconstruction of the pelvic bony landmarks on the accuracies of operative anteversion (left) and inclination (right) for a range of cup orientations. These plots demonstrate that the accuracies can vary up to 2 deg for anteversion (left plot) and up to 1 deg (right plot) depending of the orientation of the acetabular cup. All measurements are in degrees.