Backside wear is low in retrieved modern, modular, and nonmodular acetabular liners.

Overview

UNLABELLED: Modern modular components with maximized conformity between liner and shell, improved locking mechanisms, and smooth inner surfaces should have less backside wear than first-generation modular designs. Also, nonmodular components should show no backside wear in vivo. We compared the backside wear of retrieved liners from nonmodular and modular components from first-generation and second-generation designs. We matched for time in situ, patient age and weight for nine retrieved Harris-Galante Type 1 liners, nine Harris-Galante Type 2 liners, nine Trilogy liners, and nine Implex nonmodular liners. The backside of the liners was divided in quadrants, examined under a x10 binocular loupe, and rated by a score of 0 (absence of wear) to 3 (severe backside wear) for a total ranging from 0 to 12. The average total backside wear score was 8.4 for the Harris-Galante Type 1 liner, 7.3 for the Harris-Galante Type 2 liner, 3.7 for the Trilogy liner, and 2.3 for the Implex liner. We observed a significant reduction in the backside wear of modern modular and nonmodular acetabular components (Trilogy(R) and Implex) when compared with first-generation modular designs (Harris-Galante Types 1 and 2). Nonmodular acetabular cups had a low backside wear in vivo. LEVEL OF EVIDENCE: Therapeutic study, Level III (retrospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.