Variations of caudal, central, and cranial acetabular anteversion according to the tilt of the pelvis.

Variations of acetabular anteversion measured at the level of the diameter of the acetabulum according to the tilt of the pelvis are known. But the values of this anteversion at other levels of the acetabulum, near the roof or near the obturator foramen, are unknown. Attracted by the very changeable morphology of the acetabular cover, we studied the caudal, central, and cranial acetabular anteversion of 12 pelvises in four positions of dorsal-ventral inclination. The caudal, central, and cranial acetabular anteversion diminished with the ventral tilt of the pelvis. The anteversions also diminished from the caudal part of the acetabulum to the cranial part, whatever the inclination of the pelvis. These notions represent a reference that, once completed with clinical studies of healthy volunteers and patients presenting an anomaly of the acetabulum cover, will enable researchers to define threshold values of normal and pathological conditions.