Change in pelvic sagittal inclination from supine to standing position before hip arthroplasty

• Published in: The Journal of arthroplasty 2017-08, Vol.32 (8), p.2568-2573
• Main Authors: Uemura, Keisuke, MD, Takao, Masaki, MD, PhD, Otake, Yoshito, PhD, Koyama, Koki, Yokota, Futoshi, PhD, Hamada, Hidetoshi, MD, PhD, Sakai, Takashi, MD, PhD, Sato, Yoshinobu, PhD, Sugano, Nobuhiko, MD, PhD
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Arthroplasty, Replacement, Hip; automatic measurement; Female; hip; Humans; Male; Middle Aged; Orthopedics; Osteoarthritis - surgery; Osteonecrosis - surgery; Pelvic Bones - diagnostic imaging; Pelvic Bones - physiology; pelvic sagittal inclination; Pelvis; Posture; Rotation; standing position; Supine Position; total hip arthroplasty; Young Adult
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2017.03.015

Abstract Background Cup anteversion and inclination are important for avoiding implant impingement and dislocation in total hip arthroplasty (THA). However, functional cup anteversion and cup inclination also change as the pelvic sagittal inclination (PSI) changes. Therefore, PSI in both supine and standing positions was measured in a large cohort in this study. Methods A total of 422 patients (median age: 61, range: 15-87) who underwent THA were the subjects of this study. There were 83 patients with primary OA, 274 patients with DDH-derived secondary OA, 48 patients with osteonecrosis, and 17 patients with rapidly destructive coxopathy (RDC). Preoperative PSI in supine and standing positions was measured by automated CT segmentation and landmark localization of the pelvis followed by intensity-based 2D-3D registration, and the number of cases in which PSI changed more than 10° posteriorly was calculated. Hip disease, sex, and age were analyzed if they were related to a PSI change of more than 10°. Results The median PSI was 5.1° (interquartile range [IQR]: 0.4 to 9.4°) in supine and -1.3° (IQR: -6.5 to 4.2°) in standing position. There were 79 cases (19%) in which the PSI changed more than 10° posteriorly from supine to standing. Elder age and patients with primary OA and RDC were revealed to be the related factors. Conclusions PSI changed more than 10° posteriorly from supine to standing in 19% of cases. Age and diagnosis of primary OA and RDC were the significant factors for the posterior rotation.