Hip Ultrasound in Infants (Developmental Dysplasia): Graf ProtocolMain Content
- Dr. Segnini
- Jan 19
- 3 min read
Early Detection That Changes Lives
Developmental Dysplasia of the Hip (DDH) is a malformation of the hip joint that, if not diagnosed and treated early, can lead to limping, pain, and early-onset osteoarthritis in adulthood. Hip ultrasound using the Graf method is the gold standard for its diagnosis in infants (0-6 months), as it visualizes the cartilage (invisible on X-ray) and allows for a dynamic, non-radiating evaluation of the joint.
The Superiority of Ultrasound in Screening for DDC
Direct Visualization of Cartilage: Allows viewing of the cartilaginous femoral head and the roof of the acetabulum, evaluating its shape and coverage.
Static and Dynamic Evaluation: The Graf method evaluates morphology at rest, and also allows observation of the stability and reducibility of the hip with gentle maneuvers.
Objective Quantitative Classification: It is based on the measurement of angles, which minimizes subjectivity and allows for accurate monitoring of evolution.
Screening and Follow-up: It is the ideal tool for screening babies with risk factors (family history, breech presentation) and for monitoring the effectiveness of harness treatment (such as the Pavlik harness ).
Graf Protocol: Technique, Measurements and Classification
The examination is performed with a high-frequency linear transducer (≥7.5 MHz), with the baby lying on its side and the hip in slight flexion.
A) Neutral Coronal Section (Standard View): This is the fundamental section for measuring angles. Three key structures must be identified:
Baseline: Formed by the iliac bone.
Bony Roof: The rim of the acetabulum.
Labrum Cartilage : Tip of the cartilaginous roof ( echoic ).
Angle Measurement (Graph Classification):
Alpha angle (α): Measures the inclination of the bony roof . Indicates the depth of the acetabulum.
Normal: >60°. Indicates a well-formed acetabulum.
Limit / Immature: 50° - 59°.
Pathological ( Dysplastic ): <50°. Index of a flat and underdeveloped acetabulum.
Beta Angle (β): Measures the inclination of the labral cartilage . Indicates cartilaginous coverage.
Normal: <55°. Indicates good coverage of the femoral head.
Increased in subluxated /dislocated hips: >55°. The labrum is displaced upwards.
Barlow and Ortolani Maneuver ): This is performed under ultrasound guidance to confirm stability. Gentle pressure is applied to assess whether the hip dislocates ( Barlow ) or whether a dislocated hip reduces ( Ortolani ).
C) Simplified Graph Classification and Handling:
Type I (α >60°): Normal mature hip. No treatment required.
Type II (α 50°-59°): Immature hip. Ultrasound monitoring. It is subdivided into IIa (<3 months, physiological) and IIb (>3 months, requires monitoring).
Type III (α <50°, increased β): Subluxated hip . The femoral head is decentered but in contact with the acetabulum. Requires treatment with a harness.
Type IV (α <50°, greatly increased β): Dislocated hip . The femoral head is completely out of the acetabulum. Requires immediate treatment (harness or closed reduction).
Limitations and Key Considerations
Operator Dependence: This technique requires specific training and strict standardization to obtain correct cuts and reliable measurements.
Optimal Time: It is recommended to perform it from 4-6 weeks of age to allow the physiological maturation of immature hips and avoid false positives in the first month.
Complementarity: In complex cases or after closure of the femoral ossification center (≈6 months), plain radiography takes over.
Conclusion
Hip ultrasound using the Graf method is one of the most valuable applications of ultrasound in pediatrics. Its correct implementation in screening programs allows for the early, non-invasive, and objective diagnosis of developmental dysplasia of the hip (DDH), enabling the implementation of a simple treatment (brace) that prevents the serious lifelong consequences of untreated dysplastic hip.
Hip ultrasound in infants
Dr. Jose Segnini, Radiologist / Diagnostic Medical Sonographer
MD Radiologist (Venezuela – Chile)
Board Certified Diagnostic Medical Sonographer (ARDMS, USA)
Mobile Ultrasound & Medical Supplies – Orlando, Florida
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