Dual Mobility vs Constrained Liners in Managing Instability After Revision Total Hip Arthroplasty: A Systematic Review and Exploratory Cost-Effectiveness Model

Abstract

Recurrent dislocation following revision total hip arthroplasty (THA) remains a major clinical challenge. Dual-mobility (DM) constructs and constrained liners (CLs) are commonly used to improve stability; however, direct comparative evidence remains limited. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Multiple databases were searched from January 2000 to October 2025 for studies comparing DM constructs and CLs in revision THA. The primary outcomes were dislocation and aseptic re-revision, while secondary outcomes included implant survivorship, patient-reported outcome measures (PROMs), patient- and construct-related risk factors, and non-revision complications. Due to heterogeneity in study designs, results were synthesized descriptively. Ten comparative observational studies comprising 2,046 revision hips (1,237 DM and 809 CL) were included. DM constructs were associated with lower reported dislocation and aseptic re-revision rates compared with CLs. Five-year re-dislocation-free survivorship ranged from 78% to 85% across comparative cohorts. In registry-based analyses, the 10-year cumulative aseptic re-revision rate was 8.6% for DM and 13.1% for CLs. PROMs, assessed using the modified Harris Hip Score (mHHS), improved similarly in both groups. No included comparative study reported primary cost or cost-utility data. However, external economic models suggest potential cost-effectiveness advantages with DM constructs. These benefits were driven primarily by lower complication rates and fewer re-revisions. In revision THA, DM constructs are consistently associated with lower postoperative instability compared with CLs in comparative observational studies. Evidence regarding reductions in aseptic re-revision is heterogeneous, reflecting competing failure mechanisms and the limitations of non-randomized data. Economic implications remain uncertain due to the absence of primary cost-utility analyses. Implant selection should therefore be individualized, and high-quality prospective comparative studies with standardized outcome reporting are needed to define optimal construct selection in revision THA.