Developmental Hip Dysplasia Diagnosis at Three-dimensional US: A Multicenter Study.

Area of Science:

• Radiology
• Orthopedics
• Medical Imaging

Background:

• Developmental dysplasia of the hip (DDH) requires accurate early diagnosis.
• Conventional 2D ultrasound (US) has limitations in fully characterizing hip joint geometry.
• Three-dimensional (3D) US offers potential for improved acetabular shape analysis.

Purpose of the Study:

• To validate the diagnostic accuracy of DDH using geometric properties of acetabular shape from 3D US.
• To compare the performance of 3D US indexes with conventional 2D US for DDH diagnosis.

Main Methods:

• Retrospective multi-institutional study of 1728 infants evaluated for DDH.
• 3D US data was acquired alongside conventional 2D US.
• Custom software automatically calculated 3D acetabular shape indexes (e.g., posterior and anterior alpha angle).

Main Results:

• 3D US indexes showed high diagnostic performance, with an area under the receiver operating characteristic curve of 0.996.
• 3D US correctly categorized 97.5% of dysplastic and 99.4% of normal hips.
• 3D US reduced borderline cases requiring follow-up imaging by over two-thirds.

Conclusions:

• Automatically calculated 3D indexes of acetabular shape are equivalent to high-quality 2D US for DDH diagnosis.
• 3D US enhances diagnostic accuracy and efficiency, reducing the need for repeat imaging in borderline cases.