title: A shallow chest correlates with the aortic position in the normal spine: features resembling those observed in structural scoliosis.
abstract: BACKGROUND
  Right thoracic curvature, rib cage deformities and aortic left shift are features of adolescent idiopathic scoliosis that are correlated with each other. We recently reported that disturbance of ribcage development results in progressive thoracic scoliosis in mice. Recently, it has been confirmed that the normal spine exhibits right thoracic curvature and rib cage deformities and that these deformities worsen during the adolescent period. The purpose of this study was to examine whether rib cage deformities correlate with thoracic side curvature in the normal spine, as observed in scoliosis, which is important basic knowledge needed to elucidate the causative factors of adolescent idiopathic scoliosis.
  
  
  METHODS
  To examine the relationship between rib cage deformities and thoracic side curvature in the normal spine, CT scans of 148 consecutive adult females were examined. The anteroposterior chest dimension, aortic location and rib cage rotation were measured on CT scans obtained at the T8 level. The thoracic side curvature (T5-T12) was also measured on chest radiographs.
  
  
  RESULTS
  The anteroposterior chest dimension exhibited a significant correlation with aortic left shift. The aortic location and rib cage rotation were correlated, and the rib cage rotation and thoracic side curvature were correlated.
  
  
  CONCLUSIONS
  There was a significant correlation between a shallow chest and the aortic position, between the aortic position and the rib cage rotation and between the rib cage rotation and the thoracic side curvature in the normal spine. These findings suggest the possibility that rib cage development is one of the causative factors of adolescent idiopathic scoliosis.
authors.affiliation: Department of Orthopaedic Surgery, Kyushu University Beppu Hospital, 4546 Tsurumi, Beppu, Oita 874-0838, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Kyushu University Beppu Hospital, 4546 Tsurumi, Beppu, Oita 874-0838, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Tono
authors.affiliation: Department of Orthopaedic Surgery, Kyushu University Beppu Hospital, 4546 Tsurumi, Beppu, Oita 874-0838, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tarukado
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Harimaya
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Okada
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Hayashida
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
keywords: Aorta; Rib cage deformity; Scoliosis; Shallow chest