Effectiveness of Trabecular Metal^™ Acetabular Augment in Revision THR of Pelvis With Severe Acetabular Defect: A Finite Element Study

Osteolysis of the pelvis after total hip replacement (THR) can result in several types of bony defects within or around the acetabulum [1]. These defects are classified into various categories based on the extent and location of the host bone loss [2, 3]. A severe acetabular defect with at least 30% of bone loss and progressive amounts of superior rim deficiencies can be classified as a Paprosky type IIIA cavitary defect [4] (Figure 1-I). A significant amount of superior migration of the cup can be expected as the deficient acetabulum with nonsupportive superior dome will be unable to support an acetabular component at the anatomic hip center without using structural allograft, custom implants or reconstruction cage [4, 5]. A new reconstructive technique (Figure 1-II) uses modular Trabecular Metal^™ (TM) augments (Figure 1-III) to fill the acetabular defects at the time of revision THR so that regular hemispheric uncemented acetabular components can be used to allow for the potential of biologic fixation.