1. A Novel Approach for Determining Three-Dimensional Acetabular Orientation: Results from Two Hundred Subjects
by Sean W. Higgins, E. Meade Spratley, Richard A. Boe, Curtis W. Hayes, William A. Jiranek, and Jennifer S. Wayne
J Bone Joint Surg Am
Volume 96(21):
November 5, 2014
©2014 by The Journal of Bone and Joint Surgery, Inc.

2. Three points (green) were manually located on each acetabular rim to form a circle (yellow) to begin the analysis.
Three points (green) were manually located on each acetabular rim to form a circle (yellow) to begin the analysis. The surface of the acetabular rim, anterior superior iliac spine, and pubic tubercles were roughly captured (blue), and the coordinates of the facet vertices exported as point clouds (pink). The whole body image indicates the orientation of the hemipelvic view.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

3. Automatically selected points along the acetabular rim (red) were used to fit a least-squares plane that established the acetabular axis (normal vector—green arrow).
Automatically selected points along the acetabular rim (red) were used to fit a least-squares plane that established the acetabular axis (normal vector—green arrow).
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

4. The most ventral points automatically located on the anterior superior iliac spine and pubic tubercles bilaterally (red) were used to establish the three-dimensional pelvic reference frame.
The most ventral points automatically located on the anterior superior iliac spine and pubic tubercles bilaterally (red) were used to establish the three-dimensional pelvic reference frame. The anterior pelvic plane, or coronal plane (yellow), consisted of the anterior superior iliac spine bilaterally and the midpoint between the pubic tubercle points (green). The sagittal plane (pink) contained the line (dashed) in the anterior pelvic plane perpendicular to the line connecting the anterior superior iliac spines and normal to the coronal plane. The axial plane (blue) was normal to both coronal and sagittal planes.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

5. Standard measures of anteversion (red) and inclination (blue ) of the acetabular axis (green arrow) on the left acetabulum, showing anatomic anteversion (AA) and inclination (AI) (left), radiographic measures of anteversion (RA) and inclination (RI) (center...
Standard measures of anteversion (red) and inclination (blue ) of the acetabular axis (green arrow) on the left acetabulum, showing anatomic anteversion (AA) and inclination (AI) (left), radiographic measures of anteversion (RA) and inclination (RI) (center), and operative measures of anteversion (OA) and inclination (OI) (right).
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

6. Mean anatomic anteversion, measured from the coronal plane to the projection of the acetabular axis (light green arrow to green arrow) onto the axial plane, depicted on the left acetabulum for the entire population (mean and standard deviation, 23.2° ± 6.6°).
Mean anatomic anteversion, measured from the coronal plane to the projection of the acetabular axis (light green arrow to green arrow) onto the axial plane, depicted on the left acetabulum for the entire population (mean and standard deviation, 23.2° ± 6.6°). Scatterplot displaying differences between male and female subjects with regard to mean anteversion (red bars) with 95% CI of the mean (green bars), denoting how much uncertainty exists in the measurement of the mean. Nineteen acetabula (yellow) in fourteen subjects measured outside ±2 standard deviations, with three male subjects having low measures bilaterally and one female and one male subject having high measures bilaterally.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

7. Mean anatomic inclination of the acetabular axis (green arrow) depicted on the left acetabula for the entire population (mean and standard deviation, 56.5° ± 4.3°).
Mean anatomic inclination of the acetabular axis (green arrow) depicted on the left acetabula for the entire population (mean and standard deviation, 56.5° ± 4.3°). Projection of measure (gray arrow) onto coronal plane shown for perspective. Scatterplot displaying differences between male and female mean anteversion (red bars), with 95% CI of the mean (green bars), denoting how much uncertainty exists in the measurement of the mean. Twenty-one acetabula (yellow) in sixteen subjects were measured outside ±2 standard deviations, with two male and two female subjects having low measures bilaterally and one female subject having high measures bilaterally.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

8. Frequency and magnitude of intrapatient bilateral differences for anatomic anteversion (left side minus right), showing relative symmetry.
Frequency and magnitude of intrapatient bilateral differences for anatomic anteversion (left side minus right), showing relative symmetry.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.

9. Frequency and magnitude of intrapatient bilateral differences for anatomic inclination (left side minus right), showing relative symmetry.
Frequency and magnitude of intrapatient bilateral differences for anatomic inclination (left side minus right), showing relative symmetry.
Sean W. Higgins et al. J Bone Joint Surg Am 2014;96:
©2014 by The Journal of Bone and Joint Surgery, Inc.