Predictability of Acetabular Component Angular Change with Postural Shift from Standing to Sitting Position

Ante-inclination during sitting results in a more vertical acetabular cup, which can result in hip instability, especially drop-out dislocation, and edge-loading wear. Patients with supine coronal cup inclination of ≥50° and anteversion of ≥25° and those with a hypermobile pelvis are at risk. It is the pelvic spatial position during postural change that creates the postoperative consequences of the surgical cup placement.