Novel full-ceramic monoblock acetabular cup with a bioactive trabecular coating: Design, fabrication and characterization

Abstract

Over the last 25 years, the philosophy behind an optimal fixation of orthopaedic implants to hard tissues progressively evolved towards "bone-conservative" solutions in order to minimize bone resection/loss and maximize tissue-implant integration. Hence, the researchers' attention moved from "traditional" fixation of the prosthesis to host bone by using screws or acrylic cement to new strategies based on physico-chemical bonding and surface modification of the implant. This research work explores the feasibility of a novel bioceramic monoblock acetabular cup for hip joint prosthesis that can be fixed to the patient's bone by means of a bone-like trabecular coating able to promote implant osteointegration. Sponge replica method was properly adapted and optimized to produce hemispherical foam-like bioactive glass-ceramic coatings that were joined to Al2O3/ZrO2composite cups by the interposition of a glass-ceramic interlayer. Morphological analyses by scanning electron microscopy (SEM) and micro-computed tomography revealed the good quality of joining at the different interfaces. Preliminary investigation of the mechanical properties was carried out to evaluate the suitability of the device for biomedical use. In vitro bioactive behaviour was assessed by immersion studies in simulated body fluid and evaluating the apatite formation on the struts of the trabecular coating. The concepts and findings reported in the present work can have a significant impact in the field of implantable devices, suggesting a valuable alternative to currently-applied but often suboptimal techniques for bone-prosthesis fixation.