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

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Medical device engineering

Background:

• First-generation modular acetabular components exhibited significant backside wear.
• Advancements in modular and nonmodular designs aimed to reduce wear and improve implant longevity.
• Understanding in vivo wear patterns is crucial for evaluating hip implant performance.

Purpose of the Study:

• To compare the backside wear of retrieved acetabular liners from first-generation modular, second-generation modular, and nonmodular designs.
• To evaluate the in vivo performance of different acetabular component designs regarding backside wear.

Main Methods:

• Retrospective comparative study (Level III evidence).
• Analysis of nine retrieved Harris-Galante Type 1 (first-generation modular), nine Harris-Galante Type 2 (second-generation modular), nine Trilogy (modern modular), and nine Implex (nonmodular) liners.
• Matched components for time in situ, patient age, and weight.
• Backside wear assessment using a 0-3 scoring system per quadrant (0-12 total score) under a x10 binocular loupe.

Main Results:

• Average total backside wear scores: Harris-Galante Type 1 = 8.4, Harris-Galante Type 2 = 7.3, Trilogy = 3.7, Implex = 2.3.
• Significant reduction in backside wear observed in modern modular (Trilogy) and nonmodular (Implex) components compared to first-generation modular designs (Harris-Galante Types 1 & 2).
• Nonmodular acetabular cups demonstrated low in vivo backside wear.

Conclusions:

• Modern modular and nonmodular acetabular components exhibit substantially reduced backside wear compared to earlier modular designs.
• Nonmodular acetabular cups show promising low wear rates in vivo.
• These findings suggest improved durability and potentially longer lifespan for contemporary acetabular implant designs.