Acetabular bone loss in revision total hip arthroplasty: principles and techniques.

Bone stock deficiency presents the major challenge in acetabular reconstruction during revision hip arthroplasty. The preoperative assessment of acetabular bone stock before revision surgery is critical because the amount and location of pelvic osteolysis can determine the type and success of revision surgery. Traditionally, plain radiographs with AP and lateral views have been used for this purpose; however, Judet views can provide additional information about the integrity of the anterior and posterior columns. CT and MRI scans are indicated in selected patients. A variety of surgical options are available for treating Paprosky type 3 defects. Jumbo cups, the high hip center technique, impaction grafting, bilobed implants, antiprotrusio cages, and structural allografts, in addition to other types of implants, are part of the armamentarium available for revision hip arthroplasty. Segmental bone loss involving more than 50% of the acetabulum is one of the biggest challenges in revision hip replacement. The short-term clinical and radiographic results of treating these large defects with modular, highly porous metal components appear promising. However, potential problems with these components include their unknown long-term durability, potential for debris generation at the shell-augment interface, potential for fatigue failure, and the inability to restore bone stock if future revisions are needed.