Does ischial screw fixation improve mechanical stability in revision total hip arthroplasty?

Ischial screw fixation, albeit technically challenging, is postulated to provide additional mechanical stability in revision total hip arthroplasty (THA). Hemipelvis specimens were prepared to simulate revision THA, and an acetabular component with supplemental screw fixation was implanted. Three configurations were tested: 2 dome screws alone, 2 dome screws plus an additional screw within the dome, and 2 dome screws plus an ischial screw. Force displacement data were acquired during mechanical testing. An increase in mechanical stability was observed in acetabular components with supplemental screw fixation into either the posterior column or ischium (P≤.031) compared to isolated dome fixation. In addition, supplemental ischial screw fixation may provide a modest advantage over a screw placed posteroinferiorly within the acetabular dome during revision THA.