title: Characteristics of sagittal spino-pelvic alignment in Japanese young adults.
abstract: METHODS
  Radiological analysis of normal patterns of sagittal alignment of the spine.
  
  
  OBJECTIVE
  This study aimed to clarify the characteristics of normal sagittal spino-pelvic alignment in Asian people.
  
  
  BACKGROUND
  It is known that there are differences in these parameters based on age, gender, and race. In order to properly plan for surgical correction of the spine for Asian patients, it is necessary to understand the normal spino-pelvic alignment parameters for this population.
  
  
  METHODS
  This study analyzed 86 Japanese healthy young adult volunteers (48 men and 38 women; age 35.9±11.1 (mean±standard deviation [SD]). The following parameters were measured on lateral standing radiographs of the entire spine: sagittal vertical axis (SVA), horizontal distance between the C7 plumb line and the posterior superior corner of the superior margin of S1, thoracic kyphotic angle (TK), lumbar lordotic angle (LLA), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI).
  
  
  RESULTS
  The values (mean±SD) of SVA, TK, LLA, SS, PT, and PI were 8.45±25.7 mm, 27.5±9.6°, 43.4±14.6°, 34.6±7.8°, 13.2±8.2°, and 46.7±8.9°, respectively. The Japanese young adults evaluated in this study tended to have a smaller PI, LLA, TK, and SVA than most Caucasian people. Regarding gender differences, SVA was significantly longer and TK was significantly smaller in men; however, there was no statistically significant difference in LLA, SS, PA, and PI.
  
  
  CONCLUSIONS
  Japanese young adults apparently have smaller PI and LLA values than Caucasian people. When making decisions for optimal sagittal spinal alignment, racial differences should be considered.
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Endo
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Nishimura
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Shishido
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
keywords: Adult spine; Normal patterns; Sagittal alignment