Cup-cage construct provides options for large defect acetabular revisions
In most acetabular revisions, an uncemented hemispherical socket with screws can be used (Figures 1 and 2). At the Mayo Clinic in Rochester, Minn., we routinely use morselized allograft for small cavitary defects and we use screws in 100% of our revision cases. However, in the past 15 years, we have learned that not all ingrowth surfaces are equal. There are limitations to the use of uncemented hemispheres alone, such as cases that involve huge deficiencies in which an allograft bears most of the cup, pelvic discontinuity, and in pathologic bone.