Outcomes of a Novel Modular Porous Acetabular Shell in Revision Total Hip Arthroplasty

Abstract

Background: Modular porous acetabular shells were developed for use in revision Total Hip Arthroplasty (rTHA) where severe bone loss may impede implant fixation and osteointegration. This study reports one- and two-year outcomes of a novel modular porous acetabular shell in rTHA. Aim: To report short-term outcomes of a novel modular porous acetabular shell for the treatment of acetabular bone loss in rTHA. Methods: A retrospective study of 100 patients who received a novel modular porous acetabular shell in rTHA with minimum one year of follow-up was conducted at a large academic medical center between December 2018 and June 2022. Data was collected on patient demographics, surgical information, clinical outcomes and Patient Reported Outcome Measures (PROMs). The primary outcome was rate of shell re-revision. Results: The main indication for revision was aseptic loosening. A Paprosky acetabular defect of 2A or greater was found in all patients. Revision-free survivorships of the modular porous acetabular shell were 97% at one year and 96% at two years of follow-up. Among patients who retained their shell at one year, osteointegration was 100% and shell migration was 0%. Three shells (3.0%) were re-revised by one year due to dislocation (1.0%), acetabular fracture nonunion (1.0%) and infection (1.0%). One shell (1.9%) required re-revision by two years of follow-up due to infection. All four re-revised shells failed to osteointegrate prior to re-revision – two due to infection, one due to periprosthetic fracture nonunion and one was revised too early to achieve osteointegration. Conclusion: This novel modular porous acetabular shell in rTHA demonstrates excellent osteointegration and survivorship at both one and two years of follow-up.