Ultrasound Screening of Infant Hip Joints: Timing, Indications, and Methods Graf/Terjesen/Harcke
Optimal Screening Timing
One of the protocols for ultrasound screening of hip dysplasia is based on clinical examination data. If deviations are detected during the Barlow and Ortolani tests, ultrasound examination is performed:
- in patients younger than 2 weeks — if the joint is unstable;
- at the age of 4–6 weeks — in the presence of a stable click (Jacobson, 2026).
This approach considers the physiological feature: minimal physiological laxity of the ligamentous apparatus may disappear within the first month of life without treatment (Jacobson, 2026).
Age Limitations of the Method
Ultrasound is the preferred imaging tool for infant hip joints, but its informativeness depends on age (Griffith, 2025):
| Age | Ultrasound Informativeness |
|---|---|
| Up to 6 months | Method is useful |
| 6–9 months | Limited informativeness |
| After 9 months | Not used — view obstructed by ossification of the femoral head |
Technical Recommendations for the Protocol
According to protocol recommendations (Griffith, 2025):
- Up to 3 months, a linear transducer >10 MHz is used; for a large infant, 7.5 MHz is preferable for visualizing the ischial bone (bony landmarks are more important).
- Position — lateral decubitus or supine, with standard orthogonal planes; hip and knee in slight flexion.
- Definitions of capsular laxity, subluxation, and dislocation should be clearly understood by interpreting physicians; it is advisable to include these definitions in the ultrasound protocol template.
- It is useful to continue scanning the joint during active movements, even if the child is restless.
Assessment Methods
Both static and dynamic methods are used in practice. The Graf method is based on measuring the alpha angle and assessing the coverage of the femoral head; a correlation between head coverage and the alpha angle by Graf in infants during DDH screening is described (Hagen-Ansert, 2023). Dynamic sonography of the infant hip joint is described by Harcke et al. (Harcke, Grissom, 1990; 1994) as a modern concept of newborn screening (Hagen-Ansert, 2023). The Terjesen method — [clarification needed: specific criteria are absent in the provided fragments].
Indications and Risk Groups
The main clinical indication is deviations in the Barlow and Ortolani tests (joint instability or stable click) (Jacobson, 2026). A specific list of DDH risk factors is not detailed in the provided fragments — [clarification needed].
Frequently asked questions
At what age is hip joint ultrasound screening optimal?
At 4–6 weeks in the presence of a stable click; in case of an unstable joint (positive Barlow/Ortolani), by 2 weeks (Jacobson, 2026).
Until what age does hip joint ultrasound remain informative?
Ultrasound is useful up to 6 months, limitedly informative at 6–9 months, and not used later due to ossification of the femoral head (Griffith, 2025).
Why is the examination postponed to 4–6 weeks in the presence of a stable click?
Minimal physiological ligament laxity may disappear within the first month of life without treatment (Jacobson, 2026).
What transducer should be used for an infant under 3 months?
A linear transducer >10 MHz; for a large infant, 7.5 MHz is preferable for visualizing the ischial bone (Griffith, 2025).
What is the Graf method based on?
On measuring the alpha angle and assessing the coverage of the femoral head; a correlation between head coverage and the alpha angle by Graf is described (Hagen-Ansert, 2023).