Association between early sonographic findings and acetabular index at the age of 6 months: a prospective observational study

Abstract

Background This study investigated the association between early Graf classification and femoral head coverage (FHC) with the acetabular index (AI) at the age of 6 months. Methods A prospective observational study was conducted between 2017–2018. Patients requiring Pavlik harness treatment and patients with syndromic dislocation or neurogenic dislocation were excluded. In total, 169 newborns with the first ultrasound performed at the mean age of 12.3 (0–15) days, the second ultrasound performed at the mean age of 3.2 (2.5–4.1) months, and the AI measured at the age of 6.6 (4.3–7.1) months were enrolled. The correlation between the AI and first and second alpha angles and FHC measurements, and the correlation of dysplasia in early ultrasound with dysplasia in the AI were analyzed. Results At the first ultrasound, only the FHC (P = .02) demonstrated a significant negative correlation with the AI. At the second ultrasound, both the alpha angle (P < .01) and FHC (P < .01) demonstrated a significant negative correlation with the AI. With the AI as a reference, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found to be 77%, 7%, 5%, and 81%, respectively, for the first Graf; 91%, 37%, 9%, and 98%, respectively, for the first FHC measurement; 82%, 90%, 35%, and 99%, respectively, for the second Graf; and 95%, 97%, 68% and 99%, respectively, for the second FHC measurement. Conclusions FHC and alpha angle exhibited significant negative correlations with the AI at six months, both ultrasound parameters may have the potential to predict AI in DDH screening. Compared to the ultrasound measurements taken at 2 weeks, Graf and FHC at 3 months demonstrated superior sensitivity, specificity, PPV, and NPV to detect abnormal AI. The best timing to perform ultrasound examination may need further research.

Acetabular index and acetabular depth ratio in newborns and infants aged 6 months or less with the healthy development of hips: A retrospective cross-sectional study

“…[ 1 , 2 ] Ultrasonography (USG) is required to quantify hip dysplasia in infants younger than 4 months with risk factors such as familial history and female gender and born as a breech baby or a twin. [ 3 – 5 ] Pelvic anterior-posterior radiography has been used to obtain metric values of acetabular morphology and femoral head coverage in infants older than 6 months. [ 1 , 5 , 6 ]…”

“…[ 3 – 5 ] Pelvic anterior-posterior radiography has been used to obtain metric values of acetabular morphology and femoral head coverage in infants older than 6 months. [ 1 , 5 , 6 ]…”

“…In addition to being the standard imaging modality for hip dysplasia in infants older than 6 months, AI can also be used to assess hip morphology even in infants older than 4 months, given the initiation of femoral head ossification. [ 5 , 6 ] AI provides an objective parameter of acetabular dysplasia in terms of diagnosis and grading. [ 19 ] On the other hand, ADR has been proposed for the measurement of the width and depth of the acetabulum.…”

“…[1,2] Ultrasonography (USG) is required to quantify hip dysplasia in infants younger than 4 months with risk factors such as familial history and female gender and born as a breech baby or a twin. [3][4][5] Pelvic anterior-posterior radiography has been used to obtain metric values of acetabular morphology and femoral head coverage in infants older than 6 months. [1,5,6] Pelvic radiography was the only imaging modality used to image DDH before USG, which is currently regarded as the preferred imaging modality for infants younger than 4 months, became widespread.…”

“…[3][4][5] Pelvic anterior-posterior radiography has been used to obtain metric values of acetabular morphology and femoral head coverage in infants older than 6 months. [1,5,6] Pelvic radiography was the only imaging modality used to image DDH before USG, which is currently regarded as the preferred imaging modality for infants younger than 4 months, became widespread. [7,8] Nevertheless, the reproducibility of the 2 dimention ultrasonographic screening outcomes has been a matter of debate Given the unanimity of the research data, written informed consent was not taken from the legal guardians of the newborns and infants included in this study.…”