Interfacial Strength Between Porous Metal Acetabular Components and Augments.

Abstract

Background: The use of porous metal acetabular components combined with augments is a potential approach for revision hip arthroplasty in cases of severe bone defects. However, the strength of the augment-acetabular cup interface has not been studied previously. This study evaluated the interfacial strength between acetabular cups and augments.

Methods: The strength of the interface between the augment, bone cement, and the acetabular cup was tested using lever-out test. The effects of contact area and type of bone cement on the interface strength were investigated.

Results: The interfaces exhibited excellent stability. With the same cup-augment combination and different bone cements with different properties, no statistical differences were observed in main mechanical indicators (p > 0.05); however, when the same bone cement was used with different cup-augment combinations, the maximum moment and yield moment decreased significantly with a decrease in the contact area (p < 0.05). The interface stiffness exhibited a decreasing trend, although the difference was not statistically significant. Failure always occurred on the cement-acetabular cup side.

Conclusion: The interface between the acetabular cup and augment is stable and primarily influenced by the size of the contact area, not the type and mechanical properties of bone cement.

Clinical relevance: This study provides a theoretical basis for the use of augments during revision surgery. The factors affecting the strength were explored. This could promote the improvement of prostheses and guide the design of a new generation of prostheses.