The high hip center.

Revision of a failed acetabular component presents many challenges to the arthroplasty surgeon. The goal in most cases should be to reconstruct the acetabulum by positioning the hip center as close as possible to the anatomic hip center. However, severe acetabular bone stock deficiency and distorted acetabular anatomy often preclude placement of the acetabular component at the true anatomic hip center. In these cases, many options exist for reconstruction of the acetabulum, including placement of the cup superiorly at a high hip center. Although biomechanical studies have shown that superolateral placement of the hip center may lead to increased moments and forces across the hip (leading to potentially higher rates of loosening), superior only displacement of the hip center does not seem to adversely affect the forces about the hip. Proximal placement of the hip center facilitates contact between intact, viable host bone and the acetabular implant, thereby reducing the need for structural bone grafts, and increasing the chances for stable bony ingrowth. With proper patient selection and meticulous surgical technique, the high hip center can be a useful technique for reconstruction of the deficient acetabulum in the patient with a loose acetabular component after total hip arthroplasty.