Usefulness of measuring acetabular anterior coverage using a tomosynthesis imaging system

Area of Science:

• Radiology
• Orthopedics
• Medical Imaging

Background:

• Acetabular anterior coverage is crucial for hip joint stability.
• Early detection of hip joint abnormalities is essential for effective treatment.

Purpose of the Study:

• To compare the diagnostic utility of tomosynthesis and false profile (FP) radiography in measuring acetabular anterior coverage.
• To evaluate the reproducibility and effectiveness of tomosynthesis for assessing hip joint morphology.

Main Methods:

• Analyzed 70 hips from patients with early osteoarthritis and 60 hips from healthy volunteers.
• Measured vertical-centre-anterior margin (VCA) angles using both FP radiography (FP-VCA) and tomosynthesis in the sagittal plane (TS-VCA).
• Assessed intraobserver and interobserver reliability for both imaging modalities.

Main Results:

• The TS-VCA angle (median 54.4°) was significantly larger than the FP-VCA angle (median 43.8°).
• Tomosynthesis demonstrated higher reproducibility (intraobserver ICC 0.85, interobserver ICC 0.92) compared to FP radiography (intraobserver ICC 0.68, interobserver ICC 0.79).
• A strong positive correlation was found between TS-VCA and FP-VCA angles, with a regression indicating TS-VCA of 35° corresponding to FP-VCA of 25°.

Conclusions:

• Sagittal plane tomosynthesis is a reliable method for measuring acetabular anterior coverage, correlating well with FP radiography.
• Tomosynthesis offers high reproducibility, simple setup, low radiation dose, and versatility for hip joint imaging.
• A TS-VCA angle cut-off of 35° is effective for detecting developmental dysplasia of the hip.