Application of real-time shear wave elastography technology in healthy pediatric hip joints

Recently, pediatric hip joint diseases have received increasing attention, however, most researches focus on conventional ultrasound. The aim of our study is to explore the application of real-time shear wave elastography (SWE) technology in different tissue structures of healthy pediatric hip joints to distinguish between the normal and pathological states, and provide a normal reference range for shear wave Young's moduli for clinical practices and subsequent scientific researches.

According to the selection criteria, 189 healthy full-term infants with 378 hip joints were enrolled, including 102 males and 87 females aged 2-90 days. They were divided into three groups based on age: 0-30 days (61 patients), 31-60 days (63 patients), and 61-90 days (65 patients). All the subjects underwent routine ultrasound examination to perform Graf typing, and then subjected to the SWE. The Young's moduli of the femoral head, acetabular lip, acetabular cartilage apex, gluteus medius, gluteus minimus, and iliacus were recorded. The differences in various parts among the three groups, between the left and right sides, and between males and females were compared. The 95% medical reference value range for each part was obtained and consistency test was conducted.

There was no statistically significant difference in various parts between the left and right hip joints (P > 0.05) or between males and females (P > 0.05). There were significant differences in the femoral head, acetabular lip, and acetabular cartilage apex among the three groups (P < 0.05). The Young's moduli of the femoral head, acetabular lip, and acetabular cartilage apex were positively correlated with age (r₁ = 0.56, P < 0.05; r₂ = 0.51, P < 0.05; r₃ = 0.58, P < 0.05). The Young's moduli of the gluteus medius, gluteus minimus, and iliacus were not correlated with age (P > 0.05). The intra- and inter-observer evaluation results both had a high correlation, and the 95% Confidence Interval (95% CI) of both were relatively concentrated.

Real-time SWE technology can be used to obtain the Young's moduli of healthy pediatric hip joints and surrounding tissues, and distinguish between healthy and pathological states. This can provide a normal reference range for shear wave Young's moduli for clinical practices and subsequent scientific researches.