Analysis of acetabular version: Retroversion prevalence, age, side and gender correlations

INTRODUCTION: Studies using conventional radiographical signs and computerized tomography (CT) for retroversion of the acetabulum have reported a prevalence of up to 25%. The purpose of this study was to provide a detailed report on acetabular version, gender, age and side differences in a large cohort. MATERIALS AND METHODS: A total of 404 patients receiving a whole-body CT scan, aged between 16 and 40 years, have been included in the study. The measurement was performed in the transversal plane on three levels: cranial, central and caudal. RESULTS: The retroverted acetabulum on all three levels had a prevalence of 0.25% (95% confidence interval 0–0.7%). The average central anteversion in men was 16.46° (±4.42) and that in women was 19.31° (±5.04) (p < 0.001). Version increases with age, but a cluster analysis showed this to be a trend (p = 0.068). CONCLUSION: Women have a higher average acetabular version than men. Retroversion in a young adult population has a low prevalence when measured with conventional CT. About a tenth of the population has a significantly different contralateral acetabular version. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Global acetabular retroversion has a much lower prevalence than previously reported.