[Value of angle measurements in hip sonography. Methodological and technical analysis]

Area of Science:

• Pediatric Orthopedics
• Diagnostic Imaging
• Medical Ultrasound

Background:

• The Graf classification is a standard method for evaluating infant hip ultrasound studies.
• This classification relies on specific angle measurements to determine hip development.
• Reproducibility of these measurements is crucial for accurate diagnosis and treatment.

Purpose of the Study:

• To assess the reproducibility of the Graf classification in sonographic hip studies.
• To compare the reliability of angle measurements versus the operator's global impression.
• To analyze the influence of investigator, interpreter, and section plane on classification accuracy.

Main Methods:

• A double-blind study was conducted on 167 patients undergoing sonographic hip evaluations.
• Measurements and classifications were compared against established Graf criteria.
• Variations due to investigator, interpreter, and imaging plane were analyzed.

Main Results:

• The operator's global impression showed high reliability with only a 6% variation.
• Measured angle beta exhibited significant deviation (+/- 35%), indicating lower reproducibility.
• Classification based on visual impression was more consistent than measurement-based classification.

Conclusions:

• The global impression of the operator is a more reliable method for interpreting Graf hip ultrasound studies.
• Measured angles, specifically angle beta, demonstrate poor reproducibility and are less useful for classification.
• Relying on visual assessment may improve diagnostic consistency in pediatric hip ultrasound evaluations.