Bone Density Micro-CT Assessment during Embedding of the Innovative Multi-Spiked Connecting Scaffold in Periarticular Bone to Elaborate a Validated Numerical Model for Designing Biomimetic Fixation of Resurfacing Endoprostheses

Abstract

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.

Novel techniques for assessment of bone tissue material properties

“…Micro-CT is a commonly used tool in bone biology research and can be an extremely helpful technique for revealing important details of bone microarchitecture [10,11 ▪▪ ]. In recent years, there has been a rise in use of micro-CT imaging to assess bone morphology, such as trabecular and cortical bone morphology in animal and human specimens.…”

Subchondral Bone Relative Area and Density in Human Osteoarthritic Femoral Heads Assessed with Micro-CT before and after Mechanical Embedding of the Innovative Multi-Spiked Connecting Scaffold for Resurfacing THA Endoprostheses: A Pilot Study

“…The MSC-Scaffold preprototypes were manufactured in the Selective Laser Melting (SLM) technology on the REALIZER II 250 SLM ® machine (MTT Technologies Group, Paderborn, Germany) of Ti6Al4V powder. Details regarding the design of the MSC-Scaffold CAD models, the applied SLM process parameters, and the SLM post-processing treatment are given in [25].…”

“…The micro-CT examination was performed on the micro-CT system (GE phoenix v|tome|x s240, Waygate Technologies, Wunstorf, Germany). The micro-CT system included the specialized device designed and manufactured by our research team [25]. This device enables the mechanical embedding of the MSC-Scaffold in the femoral head specimens directly inside the scanning chamber of the micro-CT scanner and the real-time X-ray scanning control of the embedding process.…”

“…The micro-CT bone density assessment performed on animal (swine) fresh femoral heads published in [25] revealed that the embedding of the MSC-Scaffold prototype in the periarticular bone of femoral heads causes bone material densification under the embedded MSC-Scaffold that affects its mechanical properties. Therefore, it can be hypothesized: the densification of microarchitecture of subchondral trabecular bone of femoral heads from patients with OA due to the MSC-Scaffold embedding in femoral head specimens may also depend on the initial bone density in these femoral heads.…”

Capturing and characterizing geometric complexities of metal additively manufactured parts using x-ray micro-computed tomography and multiscale curvature analyses

“…Metal additive manufacturing in which focused thermal energy (e.g., laser, electron beam, or plasma arc) is used to fuse powdered materials by melting results in complicated microstructures and the formation of so-called re-entrant features. These features increase the specific surface area what is beneficial in biomedical applications [9], and can improve wetting behaviour [10] or electric charge capacitance in batteries [11]. The areal characterizations of surfaces with re-entrants by generalization of definitions covered in ISO 25178-2 was proposed by Pagani et al [3].…”