Acetabular morphologic parameters:
Normal ranges: 15-20′
Decreased ranges (retroversion): 10-14′
Increased ranges: 21-25′
…Values taken from Diane Lee – The Pelvis.
Alpha angle: >55′
Centre Edge Angle: >39′
Can the crossover sign be a reliable marker of global retroversion of the acetabulum?
>The crossover sign could pick up hips with less than normal anteversion with acceptable sensitivity but it has no enough specificity for being used as the sole indication for treatment.