What Is the Functional Spinopelvic Relationship in Three Dimensions? A CT and EOS Study

The functional orientation of the pelvis and the anatomic-functional relationship between the pelvis and spine are seldom considered by surgeons when positioning prosthetic acetabular components. Performing EOS scans in addition to pelvic CT scans can help the surgeon better understand the spinopelvic relationship and the 3D pelvic orientation in the functional supine, standing, and seated positions. This can aid the planning of THA as patients with extreme pelvic parameters and an increased risk of instability can be identified prior to the surgery, and the orientation of the acetabular cup may be adjusted accordingly.