Â BACKGROUND: The characteristics of acetabular abduction angle and anteversion in three dimensions are still unclear. This study aimed to assess the diagnostic values of acetabular abduction angle and anteversion by three-dimensional reconstruction of multi-slice spiral CT (MSCT). METHODS: To verify the reliability and accuracy of the acetabular abduction angle and anteversion by using MSCT, both manual and radiological examinations of pelves (N.=30) and acetabula (N.=60) were included in the study. The manual examination was performed with a protractor and a digital goniometer (Protractor). The radiological examination was performed by using the digital X-ray photography (DR) and MSCT (3D). The... pelvic anterior plane (PAP) served as a reference plane throughout the study. RESULTS: No significant difference was found among protractor, DR, and 3D measurement of acetabular abduction angles and anteversion angles [(16.24Â±4.74)Â°, (16.44Â±4.82)Â° vs. (15.82Â±4.62)Â°, P>0.05)]. Comparisons revealed significant positive correlations among protractor, DR, and 3D measurement of acetabular abduction angles and anteversion angles. CONCLUSIONS: Our study shows a new, reliable diagnostic tool for measuring the acetabular abduction angle and anteversion in THA or other hip surgeries.