At first glance, a newborn appears perfectly healthy. There is no pain, no deformity, nothing to raise concern. Yet beneath that calm exterior, the hip joint may be quietly unstable, a subtle condition with lifelong consequences if not detected early.
Developmental dysplasia of the hip (DDH) is one of the most important conditions we need to detect early in pediatric imaging. It represents a spectrum, from mild acetabular shallowness to complete dislocation of the femoral head. While many cases resolve spontaneously, others silently progress, leading to gait abnormalities, chronic pain, and early osteoarthritis if missed.
This is where ultrasound changes the story.
Unlike radiography, ultrasound allows us to see the neonatal hip before ossification begins. It provides a dynamic, real-time assessment, not just of the hip anatomy, but also of stability. In fact, it can mimic clinical maneuvers such as the Barlow test by applying gentle stress during examination, to assess whether the femoral head remains seated or slips out of the acetabulum.
Timing matters. Ultrasound is the modality of choice before 4–6 months of age, when the femoral head is still largely cartilaginous. But performing it too early—before 6 weeks—can lead to overdiagnosis due to physiological laxity caused by maternal hormones. Knowing when to scan is therefore just as important as knowing how.
A standard ultrasound examination relies on two key views:
- Coronal view at rest: evaluates acetabular morphology
- Transverse flexion view (with or without stress): assesses joint stability

To bring objectivity into assessment, the Graf method is the widely used technique. By identifying key anatomical landmarks (the iliac line, triradiate cartilage, and labrum), we measure two angles:
- Alpha (α) angle: reflects the bony roof of the acetabulum
- Beta (β) angle: reflects the cartilaginous roof
A normal hip typically shows an α angle ≥60° and β angle <55°. Deviations from these values help classify hips into types ranging from normal (Type I) to dislocated (Type IV). But beyond the numbers, what matters most is understanding what they represent: how well the femoral head is supported and how stable the joint truly is.
Screening strategies vary worldwide. Some healthcare systems advocate universal ultrasound screening, while others rely on selective screening based on risk factors such as breech presentation, family history, or associated musculoskeletal deformities. Interestingly, ultrasound can detect significantly more abnormalities than clinical examination alone.
But beyond protocols and measurements lies a bigger question:
How many cases are we missing simply because they look “normal” at birth?
Ultrasound gives us a unique opportunity, not just to diagnose, but to prevent. Early detection allows for simple, non-invasive treatments like harnessing, often avoiding surgery altogether.
As clinicians and sonographers, we are not just capturing images, we are shaping outcomes.
So the next time you scan a newborn hip, ask yourself:
Are you just measuring angles, or are you changing a life?
Dr. Dina Elraggal is a Radiology resident at the Medical Research Institute at Alexandria University in Egypt.
This posting has been edited for length and clarity. The opinions expressed in this posting are the author’s own and do not necessarily reflect the view of their employer or the American Institute of Ultrasound in Medicine.







