Keisuke Uemura1, Penny R Atkins2, Andrew E Anderson3, Stephen K Aoki4. 1. Department of Orthopaedics, University of Utah, Salt Lake City, Utah, U.S.A. 2. Department of Orthopaedics, University of Utah, Salt Lake City, Utah, U.S.A.; Department of Bioengineering, University of Utah, Salt Lake City, Utah, U.S.A. 3. Department of Orthopaedics, University of Utah, Salt Lake City, Utah, U.S.A.; Department of Bioengineering, University of Utah, Salt Lake City, Utah, U.S.A.; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, U.S.A; Department of Physical Therapy, University of Utah, Salt Lake City, Utah, U.S.A. 4. Department of Orthopaedics, University of Utah, Salt Lake City, Utah, U.S.A.. Electronic address: stephen.aoki@hsc.utah.edu.
Abstract
PURPOSE: To use computer models and image analysis to identify the position on the head-neck junction visualized in 10 radiographic views used to quantify cam morphology. METHODS: We generated 97 surface models of the proximal femur from computed tomography scans of 59 control femurs and 38 femurs with cam morphology-a flattening or convexity at the femoral head-neck junction. Each model was transformed to a position that represents the anteroposterior, Meyer lateral, 45° Dunn, modified false-profile, Espié frog-leg, modified 45° Dunn, frog-leg lateral, cross-table, 90° Dunn, and false-profile views. The position on the head-neck junction visualized from each view was identified on the surfaces. This position was then quantified by a clock face generated on the plane of the head-neck junction, in which the 12-o'clock position indicated the superior head-neck junction and the 3-o'clock position indicated the anterior head-neck junction. The mean visualized clock-face position was calculated for all subjects. Analysis was repeated to account for variability in femoral version. A general linear model with repeated measures was used to compare each radiographic view and anteversion angle. RESULTS: Each radiographic view provided visualization of the mean clock-face position as follows: anteroposterior view, 12:01; Meyer lateral view, 1:08; 45° Dunn view, 1:40; modified false-profile view, 2:01; Espié frog-leg view, 2:14; modified 45° Dunn view, 2:35; frog-leg lateral view, 2:45; cross-table view, 3:00; 90° Dunn view, 3:13; and false-profile view, 3:44. Each view visualized a different position on the clock face (all P < .001). Increasing simulated femoral anteversion by 10° changed the visualized position of the head-neck junction to a more clockwise position (range, 0:07 to 0:29; all P < .001), whereas decreasing anteversion by 10° visualized a more counterclockwise position (range, -0:23 to -0:08; all P < .001). CONCLUSIONS: Ten common radiographic views used to identify cam morphology visualized different clock-face positions of the head-neck junction. Our data will help clinicians to understand the position of the head-neck junction visualized for each radiographic view and make educated decisions in the selection of radiographs acquired in the clinic. CLINICAL RELEVANCE: Our findings will aid clinicians in choosing a set of radiographs to capture cam morphology in the assessment of patients with hip pain.
PURPOSE: To use computer models and image analysis to identify the position on the head-neck junction visualized in 10 radiographic views used to quantify cam morphology. METHODS: We generated 97 surface models of the proximal femur from computed tomography scans of 59 control femurs and 38 femurs with cam morphology-a flattening or convexity at the femoral head-neck junction. Each model was transformed to a position that represents the anteroposterior, Meyer lateral, 45° Dunn, modified false-profile, Espié frog-leg, modified 45° Dunn, frog-leg lateral, cross-table, 90° Dunn, and false-profile views. The position on the head-neck junction visualized from each view was identified on the surfaces. This position was then quantified by a clock face generated on the plane of the head-neck junction, in which the 12-o'clock position indicated the superior head-neck junction and the 3-o'clock position indicated the anterior head-neck junction. The mean visualized clock-face position was calculated for all subjects. Analysis was repeated to account for variability in femoral version. A general linear model with repeated measures was used to compare each radiographic view and anteversion angle. RESULTS: Each radiographic view provided visualization of the mean clock-face position as follows: anteroposterior view, 12:01; Meyer lateral view, 1:08; 45° Dunn view, 1:40; modified false-profile view, 2:01; Espié frog-leg view, 2:14; modified 45° Dunn view, 2:35; frog-leg lateral view, 2:45; cross-table view, 3:00; 90° Dunn view, 3:13; and false-profile view, 3:44. Each view visualized a different position on the clock face (all P < .001). Increasing simulated femoral anteversion by 10° changed the visualized position of the head-neck junction to a more clockwise position (range, 0:07 to 0:29; all P < .001), whereas decreasing anteversion by 10° visualized a more counterclockwise position (range, -0:23 to -0:08; all P < .001). CONCLUSIONS: Ten common radiographic views used to identify cam morphology visualized different clock-face positions of the head-neck junction. Our data will help clinicians to understand the position of the head-neck junction visualized for each radiographic view and make educated decisions in the selection of radiographs acquired in the clinic. CLINICAL RELEVANCE: Our findings will aid clinicians in choosing a set of radiographs to capture cam morphology in the assessment of patients with hip pain.
Authors: Thomas D Alter; Derrick M Knapik; Martina Guidetti; Alejandro Espinoza; Jorge Chahla; Shane J Nho; Philip Malloy Journal: Orthop J Sports Med Date: 2022-05-06
Authors: Rachel E Horenstein; Quentin Meslier; Julia A Spada; Anne Halverstadt; Cara L Lewis; Mo Gimpel; Richard Birchall; Thamindu Wedatilake; Scott Fernquest; Antony Palmer; Siôn Glyn-Jones; Sandra J Shefelbine Journal: J Orthop Res Date: 2021-01-10 Impact factor: 3.494