Sagittal pelvic morphology and balance in asymptomatic adolescents of Chinese Han nationality, a radiological study

English Keywords:Pelvis  Sagittal  Radiographic morphology  Adolescent  Han nationality

English Abstract:

  【Abstract】 Objectives： To establish a reference of the sagittal pelvic parameters in normal adolescents of Chinese Han nationality, and to explore the risk factors and possible mechanism of sagittal pelvic imbalance. Methods： A prospective cohort of 171 asymptomatic adolescents of Chinese Han nationality(male∶ female=87∶84) aged 13.1±2.0y(10-17y) was recruited. For each subject, pelvic incidence(PI), pelvic tilt(PT) and sacral slope(SS) was measured respectively from the standing full-spine lateral radiographs. Ratios of SS to PI(SS/PI) and PT to PI(PT/PI) were also calculated. According to the age distribution, all subjects were divided into two groups: Group young(10-13y, 11.7±1.1y) and Group old(14-17y, 15.0±1.1y). Intra- and inter-group comparisons of the pelvic parameters were performed by means of independent-samples t test or rank sum test; and their correlations with age were also analyzed. Moreover, the comparison of PI between the previous literatures and this study was analyzed by using one-sample t test. Results： There was no significant difference in PI, SS and PT between males and females in the present study. PI and PT in Group young were significantly lower than Group old(P<0.05); and SS remained unchanged with a slight downward trend(P>0.05). The value was greater than 0.5 for SS/PI and less than 0.5 for PT/PI. The correlations between age and PI or PT were remarkable in all the adolescents with the age of 10-17yrs(r=0.243, r=0.371) and in Group young(r=0.229, r=0.231), but no correlation in Group old(P>0.05); while there was no correlation between SS and age(P>0.05). Furthermore, PI in adolescents of Chinese Han nationality was significantly lower than that in Caucasian teenagers(P<0.05). Conclusions： There is no sex-related significant difference in PI, PT and SS. PI increases with age from 10 to 17 years old significantly, which presents more in adolescents of younger than 14 years, so it is considered that from 10 to 17 years, the pelvic growth is different during different ages.