Screening results and analysis of risk factors of developmental dysplasia of hip in infants in Tianjin / 中华骨科杂志

ABSTRACT

Objective:To investigate the Graf classification results and risk factors of infants for developmental dysplasia of the hip (DDH) by B-ultrasound screening in Tianjin.Methods:A retrospective analysis was conducted from January 2013 to December 2020 using the three-tier maternal and child health care management and the Tianjin maternal and child health information system for the early B-ultrasound screening data of 6-8 weeks old infants. The "2+1" screening model of "primary screening-re-screening-diagnostic treatment" was applied. The positive screening rate and age of infants at the time of referral for treatment in different years and different Graf classifications were analyzed, and the differences in positive infants with different sex, parity, fetal position, mode of production, gestational age, birth weight, and family history were compared. Binary logistic regression was used to analyze risk factors for DDH.Results:A total of 807 889 babies were screened, and 2 039 children (2 841 hips) were detected with B-ultrasound Graf classification count IIa and above, with the positive rate was 2.52‰ (2 039/807 889). Among the abnormal hips, 685 were type IIa(+) hips, 959 were type IIa(-) hips, 367 were type IIb hips, 262 were type IIc hips, 227 were type D hips, 265 were type III hips, and 76 were type IV hips. Type IIa(-) was the most common, accounting for 33.76% (959/2 841), type IIa(+) accounted for 24.11% (685/2 841), type D and above was 19.99%(568/2 841). The abnormality rate of the left hip was 2.02‰ (1 632/807 889), which was greater than 1.50‰ (1 209/807 889) of the right side, and the difference is statistically significant (χ 2=63.09, P<0.001). The rate of hip abnormalities in female infants was 3.27‰ (2 541/777 272), greater than 0.36‰ (300/838 506) in male infants, which the difference between the sexes had statistically significant (χ 2=1 947.871, P<0.001). The positive rate of DDH in male infants was 0.50‰ (209/419 253), and that in female infants was 4.71‰ (1 830/388 636). The detection ratio of male to female infants was 1∶8.76, and the difference in the positive rate of DDH between the sexes was statistically significant (χ 2=1 420.102, P<0.001). Different fetal position (cephalic position/breech presentation), delivery method (normal delivery/cesarean section), birth weight (normal/low weight), family history (with DDH/without DDH) showed statistically significant differences in the positive rate of DDH ( P<0.05), whereas there was no significant difference in the positive rate of DDH at different parity (first/second and above) and gestational age (term/premature) ( P>0.05). Logistic regression analysis showed that gender ( OR=10.50, P<0.001) and fetal position ( OR=3.40, P<0.001) were independent risk factors for DDH, and gestational age ( OR=0.91, P<0.001) was a protective factor for DDH. Differences in referral age of infants with different B-ultrasound Graf classification from year to year were statistically significant ( P<0.05). Conclusion:Through the "2+1" screening model of "primary screening-re-screening-diagnostic treatment", the DDH positive rate in 6-8 weeks old infants in Tianjin was 2.52‰, and the positive rate of DDH in female infants and left hip was higher. The more severe the Graf classification of B-ultrasound was, the younger the age of referral was. Women and infants with breech presentation had a higher risk of developing DDH, and the risk of DDH in preterm infants was lower.