Backside Wear Is Low in Retrieved Modern, Modular, and Nonmodular Acetabular Liners

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 ×10 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® 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.