Abstract
Introduction
Many surgeons are reluctant to use a constrained liner at the time of acetabular component revision given concerns this might result in early acetabular component loosening. We hypothesized that with appropriate initial implant stabilization of highly porous acetabular components with supplemental screw fixation, constrained liners could be safely used at the time of acetabular revision.
Methods
We retrospectively identified 148 revision total hip arthroplasties (THAs) where a constrained liner of one design was cemented into a newly placed highly porous acetabular component fixed with supplemental screws (mean 5 screws). Mean age at revision THA was 69 years, with 68% being female. The most common indications for revision were two-stage re-implantation (33%), recurrent dislocation (30%), and aseptic loosening (22% acetabular; 9% acetabular/femoral component). Mean follow-up was 8 years.
Results
There were no failures at the bone-implant interface, and there were no revisions for aseptic loosening of the acetabular component. Furthermore, all acetabular components were bone ingrown on radiographic analysis. The 10-year survivorships free from any acetabular revision and free from any reoperation were 75% and 67%, respectively. Overall, 33 hips (22%) required revision or reoperation for infection/wound complications (n=12), dislocation (n=11), periprosthetic femur fracture (n=4), femoral loosening (n=3), and other (n=3). The 10-year survivorship free from dislocation was 84% overall, which was similar to the 85% 10-year survivorship free from dislocation for those specifically revised for instability (p=0.9).
Conclusions
Implanting a constrained liner at the time of acetabular revision in high-risk patients resulted in no cases of aseptic acetabular component loosening in this large series. This is likely related to the fact that a highly porous acetabular component was utilized with a large number of supplemental screws in each case. Such information is valuable as these data favor a paradigm shift when compared to some traditionally-held tenets.
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