Analysis of the results of hip ultrasonography in 48 666 infants and efficacy studies of conservative treatment.

ABSTRACT

PURPOSE: This study aimed to investigate the detection rate of developmental dysplasia of the hip (DDH) by ultrasound. To obtain the distribution characteristics of the different types (I-IV) and the role of ultrasound in the evaluation of infants with DDH (type IIc and above) receiving conservative treatment. METHODS: A retrospective analysis was performed. The chi-square test was used for comparisons between count-data groups. Two-sided tests were used for all analyses. The results of ultrasound follow-up after conservative treatment are described. RESULTS: Among the 48 666 infants examined, the detection rates were as follows type I, 95.42%; IIa, 3.18%; IIb, 0.91%; IIc, 0.22%; D, 0.01%; III, 0.14%; and IV, 0.12%. There were 4456 hips with IIa and above, more left (54.65%) than right (45.35%) hips, and more females (82.60%) than males (17.40%). The detection rate of type IIa and above was 4.58%, and that of type IIb and above was 1.40%. After the treatment, the α value increased, and ß value decreased. The cure rate of the less-than-42-days group was higher than that of the other groups. CONCLUSION: The ultrasound detection rate of DDH is high. DDH was more likely to occur on the left side and in females. It is recommended that the infants should be treated within 42 days.