A new tilt on pelvic radiographs: a pilot study

Area of Science:

• Orthopedic imaging
• Radiographic measurement analysis

Background:

• Pelvic tilt is a common variable in hip radiography.
• Accurate measurements are crucial for diagnosing hip conditions like protrusio acetabuli and developmental dysplasia of the hip.

Purpose of the Study:

• To evaluate the effect of pelvic tilt on standard radiographic measurements used for primary protrusio acetabuli and developmental dysplasia of the hip.

Main Methods:

• A pelvic and spine skeleton model was used with varying degrees of pelvic tilt.
• Seven common radiographic measurements were assessed by two independent readers.

Main Results:

• Measurements for protrusio acetabuli showed significant variation, rendering standard radiographic tests unreliable.
• Only the inter-tuberous distance remained unaffected by pelvic tilt.
• Acetabular angles for developmental dysplasia of the hip demonstrated potential when pelvic tilt was below 15 degrees.

Conclusions:

• Increased pelvic tilt compromises the reliability of radiographic measurements for protrusio acetabuli.
• Computed tomography and magnetic resonance imaging may offer more accurate assessments due to direct visualization.
• A lateral view is recommended to assess pelvic tilt and validate measurements in protrusio cases.