Influence of Synthetic Bone Substitutes on the Anchorage Behavior of Open-Porous Acetabular Cup.

Volker Weißmann,Harald Hansmann,Rainer Bader,Tim Ramskogler,Christian Schulze

doi:10.3390/ma12071052

Abstract

Background: The development in implants such as acetabular cups using additive manufacturing techniques is playing an increasingly important role in the healthcare industry. Method: This study compared the primary stability of four selectively laser-melted press-fit cups (Ti6Al4V) with open-porous, load-bearing structural elements on the surface. The aim was to assess whether the material of the artificial bone stock affects the primary stability of the acetabular cup. The surface structures consist of repeated open-porous, load-bearing elements orthogonal to the acetabular surface. Experimental pull-out and lever-out tests were performed on exact-fit and press-fit cups to evaluate the primary stability of the cups in different synthetic bone substitutes. The acetabular components were placed in three different commercially available synthetic materials (ROHACELL-IGF 110, SikaBlock M330, Sawbones Solid Rigid). Results & conclusions: Within the scope of the study, it was possible to show the differences in fixation strength between the tested acetabular cups depending on their design, the structural elements used, and the different bone substitute material. In addition, functional correlations could be found which provide a qualitative reference to the material density of the bone stock and the press-fit volume of the acetabular cups.

Highlights

The development of new implant designs using additive manufacturing technologies [1,2,3,4,5,6] and the integration of property-improving design elements, such as open-porous structures for the treatment of large and small segmental bone defects [7,8,9], requires, inter alia, a verification of suitability for the declared objective
The motivation for this study is to evaluate of the anchorage behavior of differently dimensioned and designed press-fit acetabular cups in artificial bone materials
Experiments investigating the primary stability of acetabular cups in artificial bone are not comparable to intraoperative situations

Summary

Introduction

The development of new implant designs using additive manufacturing technologies [1,2,3,4,5,6] and the integration of property-improving design elements, such as open-porous structures for the treatment of large and small segmental bone defects [7,8,9], requires, inter alia, a verification of suitability for the declared objective. The functional properties of the implants must be demonstrated in addition to surface quality [10,11], cell biological compatibility [12,13], corrosion resistance, and mechanical strength [14,15], which are significantly influenced by the material used. These include the primary fixation strength, when the implant is placed in the bone, where it plays a decisive role in determining the success of an implantation, i.e., an insertion of an artificial acetabular cup into the bone stock [16]. The development in implants such as acetabular cups using additive manufacturing techniques is playing an increasingly important role in the healthcare industry

Objectives

Methods

Conclusion