Incidence of Liner Dissociation and All-Cause Revision With Uncemented Acetabular Components in Primary Total Hip Arthroplasty

Uncemented modular acetabular components are commonly used in total hip arthroplasty. Liner wear is uncommon since the introduction of highly crosslinked polyethylene. Our study goal was to identify the incidence of liner dissociation and all-cause revision by manufacturer.

We included 117,051 patients aged 18 years and older who underwent primary total hip arthroplasty for osteoarthritis with a unipolar acetabular component and highly crosslinked polyethylene liner between 2009 and 2022. There were six acetabular component treatment groups categorized alphabetically by manufacturer: group one (n = 25,040), group two (n = 11,819), group three (reference group) (n = 72,221), group four (n = 3,233), group five (n = 2,021), and group six (n = 2,717). Revision during follow-up was modeled using Cox proportional hazard regression.

In adjusted analysis, group one (hazard ratio [HR] = 1.51; 95% confidence interval [CI] = 1.30 to 1.75) and group four (HR = 1.35, 95% CI = 1.07 to 1.70) had higher all-cause revision risks. Liner dissociation incidence at 13 years was 0.25% for group three, 0.04% for group one, 0.00% for group four, 0.15% for group four, and 0.32% for group five. It was 0.01% for group one, which had a lower risk for revision due to liner dissociation (HR = 0.12; 95% CI = 0.04 to 0.33). The percentage of all failures attributable to liner dissociation was 0.4% for group one, 0.4% for group two, 4.0% for group three, 0% for group four, 1.2% for group five, and 0.9% for group six.

In this large United States-registry-based study, the most utilized acetabular component showed a higher incidence of liner dissociations compared to the second most used cup/liner combination in this cohort.