Background: The surgical success of cementless implants is determined by the evolution of the biomechanical properties of the bone-implant interface (BII). One difficulty to model the biomechanical behavior of the BII comes from the implant surface roughness and from the partial contact between bone tissue and the implant. The determination of the constitutive law of the BII would be of interest in the context of implant finite element (FE) modeling to take into account the imperfect characteristics of the BII. The aim of the present study is to determine an effective contact stiffness [Formula: see text] of an osseointegrated BII accounting for its micromechanical features such as surface roughness, bone-implant contact ratio (BIC) and periprosthetic bone properties. To do so, a 2D FE model of the BII under normal contact conditions was developed and was used to determine the behavior of [Formula: see text].
Results: The model is validated by comparison with three analytical schemes based on micromechanical homogenization including two Lekesiz's models (considering interacting and non-interacting micro-cracks) and a Kachanov's model. [Formula: see text] is found to be comprised between 10 and 10 N/m according to the properties of the BII. [Formula: see text] is shown to increase nonlinearly as a function of the BIC and to decrease as a function of the roughness amplitude for high BIC values (above around 20%). Moreover, [Formula: see text] decreases as a function of the roughness wavelength and increases linearly as a function of the Young's modulus of periprosthetic bone tissue.
Conclusions: These results open new paths in implant biomechanical modeling since this model may be used in future macroscopic finite element models modeling the bone-implant system to replace perfectly rigid BII conditions.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6889538 | PMC |
http://dx.doi.org/10.1186/s12938-019-0733-3 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
Dissolution of CO in water followed by the subsequent hydrolysis reactions is of great importance to the global carbon cycle, and carbon capture and storage. Despite numerous previous studies, the reactions are still not fully understood at the atomistic scale. Here, we combined ab initio molecular dynamics (AIMD) simulations with Markov state models to elucidate the reaction mechanisms and kinetics of CO in supercritical water both in the bulk and nanoconfined states.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom.
A value is conventionally interpreted either as a) the probability by chance of obtaining more extreme results than those observed or b) a tool for declaring significance at a prespecified level. Both approaches carry difficulties: b) does not allow users to make inferences based on the data in hand, and is not rigorously followed by researchers in practice, while (a) is not meaningful as an error rate. Although values retain an important role, these shortcomings are likely to have contributed significantly to the scientific reproducibility crisis.
View Article and Find Full Text PDFSci Rep
January 2025
School of Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
The use of winglet devices is an efficient technique for enhancing aerodynamic performance. This study investigates the effects of winglet cant angles on both the aerodynamics and aeroacoustics of a commercial wing, comparing them to other significant parameters using a parametric analysis. A Full Factorial Design method is employed to generate a matrix of experiments, facilitating a detailed exploration of flow physics, with lift-to-drag ratio (L/D) and the integral of Acoustic Power Level (APL) as the primary representatives of aerodynamic and acoustic performance, respectively.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemistry, Columbia University, New York, NY, USA.
Among expanding discoveries of quantum phases in moiré superlattices, correlated insulators stand out as both the most stable and most commonly observed. Despite the central importance of these states in moiré physics, little is known about their underlying nature. Here, we use pump-probe spectroscopy to show distinct time-domain signatures of correlated insulators at fillings of one (ν = -1) and two (ν = -2) holes per moiré unit cell in the angle-aligned WSe/WS system.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemical Engineering, Indian Institute of Technology, Guwahati 781039, Assam, India.
Self-organized contact line instabilities (CLI) of a macroscopic liquid crystal (LC) droplet can be an ingenious pathway to generate a large collection of miniaturized LC drops. For example, when a larger drop of volatile solvent (e.g.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!