ALBERT

Description: The multi-spiked connecting scaffold (MSC-Scaffold) prototype with spikes mimicking the interdigitations of articular subchondral bone is an essential innovation in surgically initiated fixation of resurfacing arthroplasty (RA) endoprosthesis components. This paper aimed to present a determination of the suitable range of conditions for the calcium phosphate (CaP) potentiostatic electrochemical deposition (ECDV=const) on the MSC-Scaffold prototype spikes to achieve a biomineral coating with a native Ca/P ratio. The CaP ECDV=const process on the MSC-Scaffold Ti4Al6V pre-prototypes was investigated for potential VECDfrom −9 to −3 V, and followed by 48 h immersion in a simulated body fluid. An acid–alkaline pretreatment (AAT) was applied for a portion of the pre-prototypes. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) studies of deposited coatings together with coatings weight measurements were performed. Themost suitable VECD range, from −5.25 to −4.75 V, was determined as the native biomineral Ca/P ratio of coatings was achieved. AAT increases the weight of deposited coatings (44% for VECD = −5.25 V, 9% for VECD = −5.00 V and 15% for VECD = −4.75 V) and the coverage degree of the lateral spike surfaces (40% for VECD = −5.25 V, 14% for VECD = −5.00 V and 100% for VECD = −4.75 V). XRD confirmed that the multiphasic CaP coating containing crystalline octacalcium phosphate is produced on the lateral surface of the spikes of the MSC-Scaffold. ECDV=const preceded by AAT prevents micro-cracks on the bone-contacting surfaces of the MSC-Scaffold prototype, increases its spikes’ lateral surface coverage, and results in the best modification effect at VECD = −5.00 V. To conclude, the biomimetic MSC-Scaffold prototype with desired biomineral coating of native Ca/P ratio was obtained for cementless RA endoprostheses.

Description: Our team has been working for some time on designing a new kind of biomimetic fixation of resurfacing endoprostheses, in which the innovative multi-spiked connecting scaffold (MSC-Scaffold) that mimics the natural interface between articular cartilage and periarticular trabecular bone in human joints is the crucial element. This work aimed to develop a numerical model enabling the design of the considered joint replacement implant that would reflect the mechanics of interacting biomaterials. Thus, quantitative micro-CT analysis of density distribution in bone material during the embedding of MSC-Scaffold in periarticular bone was applied. The performed numerical studies and corresponding mechanical tests revealed, under the embedded MSC-Scaffold, the bone material densification affecting its mechanical properties. On the basis of these findings, the built numerical model was modified by applying a simulated insert of densified bone material. This modification led to a strong correlation between the re-simulation and experimental results (FVU = 0.02). The biomimetism of the MSC-Scaffold prototype that provided physiological load transfer from implant to bone was confirmed based on the Huber–von Mises–Hencky (HMH) stress maps obtained with the validated finite element (FE) model of the problem. The micro-CT bone density assessment performed during the embedding of the MSC-Scaffold prototype in periarticular bone provides insight into the mechanical behaviour of the investigated implant-bone system and validates the numerical model that can be used for the design of material and geometric features of a new kind of resurfacing endoprostheses fixation.

Description: The monograph comprehensively presents the research on the prototype of the biomimetic Multi-Spiked Connecting Scaffold (MSC-Scaffold) for cementless fixation of the components of a new generation of resurfacing arthroplasty (RA) endoprostheses. This research, carried out by a bioengineering-surgical team from three Polish universities, includes bioengineering design, rapid prototyping, manufacturing in selective laser melting, functionalization, surface modification, numerical studies, experimental in vitro studies, and pilot surgical experiments in an animal model. Features: Presents the prototype of the multi-spiked connecting scaffold for a new generation of resurfacing endoprostheses of the knee and the hip Explains this prototype scaffold as the first worldwide design of the biomimetic fixation of components of diarthrodial joints resurfacing endoprostheses Insights into the entire process of bioengineering design and research on this novel way of resurfacing endoprostheses fixation Reviews main results of the scaffold prototyping and SLM manufacturing, structural and osteoconductive functionalization, and surface modification Reports experimental and numerical investigations of mechanical behavior of the scaffold-bone system, cell culture studies, and pilot surgical experiments in animal models This book is aimed at professionals and graduate students in biomedical engineering, biomaterials engineering, and bone & joint surgery. The Open Access version of this book, available at http://www.taylorfrancis.com, has been made available under a Creative Commons [Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND)] 4.0 license.