Which imaging study is best to confirm hip dysplasia in a 4-week-old infant with positive Barlow and Ortolani tests?

Which imaging study is best to confirm hip dysplasia in a 4-week-old infant with positive Barlow and Ortolani tests?

• A. Ultrasound
• B. X-ray
• C. MRI
• D. CT

Answer: (A)

When a neonate has positive Barlow or Ortolani tests, imaging that can visualize the unossified, cartilaginous hip is essential. Ultrasound is the best choice because it shows the cartilage, acetabulum, and femoral head, and it allows dynamic assessment of stability to confirm dysplasia or dislocation. It is also radiation-free and practical for infants, making it ideal for early diagnosis and guiding treatment such as a Pavlik harness. X-ray relies on bone ossification, which isn’t present at 4 weeks, so it can’t reliably detect DDH in this age. MRI could image soft tissues but is impractical for routine screening in a very young infant, and CT involves radiation. Ultrasound therefore provides the most accurate, safe confirmation at this age.

When a neonate has positive Barlow or Ortolani tests, imaging that can visualize the unossified, cartilaginous hip is essential. Ultrasound is the best choice because it shows the cartilage, acetabulum, and femoral head, and it allows dynamic assessment of stability to confirm dysplasia or dislocation. It is also radiation-free and practical for infants, making it ideal for early diagnosis and guiding treatment such as a Pavlik harness. X-ray relies on bone ossification, which isn’t present at 4 weeks, so it can’t reliably detect DDH in this age. MRI could image soft tissues but is impractical for routine screening in a very young infant, and CT involves radiation. Ultrasound therefore provides the most accurate, safe confirmation at this age.