Modular constrained devices and reconstruction cages in the management of the unstable hip in major acetabular deficiency

We retrospectively reviewed 26 patients with 28 acetabular reconstructions using constrained liner and modular, metalbacked components cemented into a reconstruction cage. All deficiencies were Type IIIC. Overall, the reoperation rate was 39.3%, including 3 aseptic failures, each occurring with breakage and failure of superior, then inferior fixation, then superomedial migration; 2 dislocations despite the constraint; and 4 deep infections. Mean HHS improvement was 36.2 points. The use of allograft bone, different component and/or cage designs was not significant for revision or infection (p>0.05). This technique is effective for extensive bone loss with instability. Modularity allows for position fine-tuning and exchange if needed.