Outcomes of isolated head-liner exchange versus full acetabular component revision in aseptic revision total hip arthroplasty

Introduction: Isolated head and liner exchange in aseptic revision total hip arthroplasty (rTHA) is an appealing option rather than full acetabular component revision; however, early outcome reports suggest high rates of complications requiring re-revision. This study seeks to compare the outcomes of these procedures. Methods: This retrospective study assessed 124 head and liner exchanges and 59 full acetabular cup revisions conducted at a single center between 2011 and 2019 with at least 2 years of follow-up. Baseline demographics did not vary by group. Mean follow-up was 3.7 (range 2.0-8.6) years. Results: In the head and liner exchange group, re-revision-free survivorship at 2 years was 79% for all-causes and 84% for aseptic reasons. In the full acetabular revision group, it was 80% for all causes (p > 0.99) and 83% for aseptic reasons (p > 0.99). The 2-year survivorship of head and liner exchange was non-inferior to that of full acetabular revision, correcting for surgical indication and history of prior revision (adj-OR 0.1.39, 95% CI, 0.62-3.28, p = 0.99). A best-fit multivariable model found that revision for instability (adj-OR=3.03, 95% CI 1.40-6.66, p = 0.005), prior revision (adj-OR 2.15; 95% CI, 0.87-5.32; p = 0.10), current smoking (adj-OR 2.07; 95% CI, 0.94-4.57; p = 0.07), and obesity (adj-OR 0.58; 95% CI, 0.24-1.36; p = 0.22) were associated with failure within 2 years. Conclusions: In this analysis, 2-year outcomes for isolated head and liner exchange were non-inferior to full acetabular component revision. A future randomised prospective study should be conducted to better assess the optimal approach to revision in an aseptic failed hip arthroplasty.