%0 Journal Article
%T Reproducibility of pelvic sagittal inclination while acquiring radiographs in supine and standing postures
%A Futoshi Yokota
%A Hidetoshi Hamada
%A Keisuke Uemura
%A Koki Koyama
%A Masaki Takao
%A Nobuhiko Sugano
%A Takashi Sakai
%A Yoshinobu Sato
%A Yoshito Otake
%J Journal of Orthopaedic Surgery
%@ 2309-4990
%D 2019
%R 10.1177/2309499019828515
%X Pelvic position on the sagittal plane is usually evaluated with the pelvic sagittal inclination (PSI) angle from a single radiograph. However, the reproducibility of pelvic positioning has not been investigated, and thus, the validity of measuring the PSI from a single film/time point is not understood. Herein, the reproducibility of a patient¡¯s pelvic positions in supine and standing postures was analyzed. A total of 34 patients who underwent either a pelvic osteotomy or total hip arthroplasty were enrolled in this study. Preoperative radiographs in both supine and standing postures were acquired twice (first X-ray and second X-ray) within 6 months; preoperative computed tomography (CT) images of the full pelvis were also acquired in a supine posture (preop-CT). To eliminate measurement variability, each PSI was automatically measured from radiographs and CT images through the use of CT segmentation and landmark localization followed by intensity-based 2D-3D registration. The absolute difference of PSI among each image was calculated and the intra-class correlation coefficient (ICC) in each posture was also analyzed. The median absolute differences of PSI in the supine posture were 1.3¡ã between the first and second X-rays, 1.2¡ã between the first X-ray and preop-CT, and 1.3¡ã between the second X-ray and preop-CT. The median absolute difference of PSI in the standing posture was 1.5¡ã. The ICC was 0.965 (95% CI: 0.939¨C0.981) in supine and 0.977 (95% CI: 0.954¨C0.988) during standing. Pelvic positions in supine and standing postures are reproducible. Thus, measuring the PSI from a single radiograph is reliable
%K automated measurement
%K CT and X-ray
%K hip surgery
%K pelvic tilt
%K 2D-3D registration
%U https://journals.sagepub.com/doi/full/10.1177/2309499019828515