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 β 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.

Role of ultrasound as a screening tool for the diagnosis of developmental dysplasia of the hip

“…They also added that the majority of these patients had type 2a hip which is mostly considered as hip immaturity rather than a true pathology and 1.40% of the hips showed Graf type 2b and above hip findings. He et al 7 reported that DDH more commonly occurs in girls and at left side in their study cohort and these findings are in line with the previous studies 3,4 …”

“…2 However, it is also reported that at this age group (4-6 months) overdiagnosis with ultrasound for DDH may be as high as 40%. 6 In this issue of Journal of Clinical Ultrasound: Sonography and Other Imaging Techniques, He et al 7 published a study in which they retrospectively analyzed the sonographic findings of infants examined for DDH screening. The fact that they included a high number of cases (97 332 hips of 48 666 infants) in the study stands out as one of the main strengths of the study.…”

“…3,4 On the other hand, the infants with Graf type 2c and above hips and who received conservative sling treatment were followed up. He et al 7 subcategorized the patients according to their age on treatment initiation and reported that the cure rate of conservative treatment in patients with age of ≤42 days was significantly higher in comparison to the groups older than 42 days. This finding may have important implications on clinical practice and can be helpful to determine a time frame for ultrasound examination.…”

“…9 However, we consider that on the experienced hands with the additional benefits of ultrasound such as low cost and lack of ionizing radiation, ultrasound is the modality of choice for DDH screening. The study of He et al 7 can be helpful to determine a potentially most beneficial time frame for ultrasound examination in clinical practice. Prospectively designed future studies are necessary for validation of these findings.…”

“…In a study conducted by Tan et al, 8 it has been reported that screening for DDH with ultrasound can be performed reliably on day 22 and beyond of life. Because none of overdiagnosis and delay of the diagnosis is demanded, when taken together the results of He et al 7 and Tan et al, 8 it can be considered that the time interval between 22 and 42 days of the life may be the most beneficial time period for ultrasound screening for DDH.…”