TM Augments in acetabularreconstruction

Thorsten Gehrke, MD
The incidence of revision total hip arthroplasty (THA) has increased during the last decade. In general, acetabularrevision following THA is a challenging procedure. The main challenging key points are bone loss, loss of structural bone support, loss of pelvic stability and poor quality of bone. Therefore, exact preoperative planning is essential to achieve successful results. The main issue is to ensure the bone loss caused by these conditions to choose the appropriate equipment and prostheses. The classification method by Paprosky is the most common used method to describe the extent of periacetabular bone loss in revision THA. For instance, Paprosky type 3 defects have severe global erosion of the acetabulum with destruction of all supporting structures and greater than 2 cm of hip center migration. Those defects can be associated with pelvic discontuinity (PD), which is the separation of the ilium proximally from the ischio-pubic region distally.

Generally, the surgical goal is to achieve long-term fixation, pain reduction and to restore function, leg length and bone stock. In cases with PD, the treatment strategyis to restore a stable continuity between the ischium and the ilium and to reconstruct the anatomical hip centre. In this context, indications, surgical technique, limitations and clinical results of TM augments in acetabular reconstruction are presented.