title: Are there gender differences in sagittal spinal pelvic inclination before and after the adolescent pubertal growth spurt?
abstract: OBJECTIVE
  Significant progression of spinal deformity could occur during the peak of pubertal growth in adolescent idiopathic scoliosis (AIS). Gender differences in spinal and vertebral inclination have been reported in asymptomatic young adults and are thought to affect the risk of curve progression in male and female AIS. The present study aimed to investigate whether there were gender differences in the sagittal spinal-pelvic profile and whether any differences occurred before or developed during the normal pubertal growth spurt.
  
  
  METHODS
  The sagittal up-right standing spine X-ray films from 71 male and 82 female asymptomatic adolescents were collected. The inclination of the global spine was analyzed by measuring the spino-sacral angle (SSA) and the spinal tilt (ST). Additionally, the inclination of the vertebrae (T1-L5), thoracic kyphosis (T4-T12) and lumbar lordosis were measured. These subjects were divided into the ascending phase (non-fused triradiate cartilage) G1 subgroup, the peak (fused triradiate cartilage and Risser grade 0-1) G2 subgroup and the late phase (Risser grade 2-5) of pubertal growth G3 subgroup. The comparisons between the males and females were carried out within the subgroups.
  
  
  RESULTS
  In the subgroups G1 and G2, the females showed a trend of less ventral inclination in the upper thoracic vertebrae (T1-T5) and greater dorsal inclination in the lower thoracic vertebrae (T7-T12), although the differences were not statistically significant. In the G3 subgroup, the females showed significantly larger SSA (133.7° ± 4.5° vs. 128.4° ± 4.0°), ST (96.3° ± 2.6° vs. 94.8° ± 3.4°) and dorsal inclination of T1 and T12-L2 than did the males (p < 0.05).
  
  
  CONCLUSIONS
  Although a trend toward a more backward inclination of the spine and individual vertebrae might pre-exist during the ascending phase or peak of pubertal growth, the differences become more significant during the late stage of puberty. The observation could be related to relatively active anterior vertebral overgrowth that occurs in females during pubertal growth.
authors.affiliation: Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road 321, Nanjing, 210008, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Wang
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.forename: Tsz Ping
authors.initials: TP
authors.lastname: Lam
authors.forename: Jack Chun-yiu
authors.initials: JC
authors.lastname: Cheng
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging; D008141:Lordosis / Q000000981:diagnostic imaging; D008297:Male; D010388:Pelvis / Q000000981:diagnostic imaging; D011627:Puberty; D011859:Radiography; D012737:Sex Factors; D013131:Spine / Q000000981:diagnostic imaging* / Q000254:growth & development*; D055815:Young Adult