BONE ADAPTATION-DRIVEN DESIGN OF PERIODIC SCAFFOLDS

2021 ◽  
pp. 1-21
Author(s):  
David O. Cohen ◽  
Sohaila M. G. Aboutaleb ◽  
Amy J. Wagoner Johnson ◽  
Julián A. Norato
Keyword(s):  
Strain Energy ◽  
Bone Growth ◽  
Bone Adaptation ◽  
Computational Method ◽  
Projection Technique ◽  
Implantation Time ◽  
Applied Loading ◽  
Geometry Projection ◽  
Simulated Time ◽  
Rabbit Femur

Abstract This work introduces a computational method for designing bone scaffolds for maximum bone growth. A mechanobiological model of bone adaptation is used to compute the bone growth, taking into account the shape of the defect, the applied loading, and the existing density distribution of the bone in which the scaffold has been implanted. Numerical homogenization and a geometry projection technique are used to efficiently obtain surrogates of the effective elastic and diffusive properties of the scaffold as a function of the scaffold design and the bone density. These property surrogates are in turn used to perform bone adaptation simulations of the scaffold-bone system for a sampling of scaffold designs. Surrogates of the bone growth in the scaffold at the end of the simulated time and of the strain energy of the scaffold at implantation time are subsequently constructed from these simulations. Using these surrogates, we optimize the design of a scaffold implanted in a rabbit femur to maximize bone growth into the scaffold while ensuring a minimum stiffness at implantation. The results of the optimization demonstrate the effectiveness of the proposed design methodology and they provide evidence that designing a scaffold with regards to bone adaptation yields larger bone growth than considering only mechanical criteria.

Analogy of Strain Energy Density Based Bone-Remodeling Algorithm and Structural Topology Optimization

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
In Gwun Jang ◽  
Il Yong Kim ◽  
Byung Man Kwak
Keyword(s):  
Topology Optimization ◽  
Energy Density ◽  
Bone Remodeling ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Optimization Method ◽  
Bone Adaptation ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Topology Optimization Method

In bone-remodeling studies, it is believed that the morphology of bone is affected by its internal mechanical loads. From the 1970s, high computing power enabled quantitative studies in the simulation of bone remodeling or bone adaptation. Among them, Huiskes et al. (1987, “Adaptive Bone Remodeling Theory Applied to Prosthetic Design Analysis,” J. Biomech. Eng., 20, pp. 1135–1150) proposed a strain energy density based approach to bone remodeling and used the apparent density for the characterization of internal bone morphology. The fundamental idea was that bone density would increase when strain (or strain energy density) is higher than a certain value and bone resorption would occur when the strain (or strain energy density) quantities are lower than the threshold. Several advanced algorithms were developed based on these studies in an attempt to more accurately simulate physiological bone-remodeling processes. As another approach, topology optimization originally devised in structural optimization has been also used in the computational simulation of the bone-remodeling process. The topology optimization method systematically and iteratively distributes material in a design domain, determining an optimal structure that minimizes an objective function. In this paper, we compared two seemingly different approaches in different fields—the strain energy density based bone-remodeling algorithm (biomechanical approach) and the compliance based structural topology optimization method (mechanical approach)—in terms of mathematical formulations, numerical difficulties, and behavior of their numerical solutions. Two numerical case studies were conducted to demonstrate their similarity and difference, and then the solution convergences were discussed quantitatively.

scholarly journals Bone Mineral Density and Jumping Height in Pre-Menarcheal and Post-Menarcheal Physically Active Girls

2018 ◽  
Vol 3 (82) ◽  
Author(s):  
Rita Gruodytė ◽  
Toivo Jürimäe
Keyword(s):  
Bone Mineral Density ◽  
Femoral Neck ◽  
Bone Mineral ◽  
Bone Health ◽  
Bone Growth ◽  
Weight Bearing ◽  
Bone Adaptation ◽  
Mineral Density ◽  
Physically Active ◽  
Vertical Jumps

Research background and hypothesis. Jumping ability correlates well with different bone values. The skeletal benefits of high-impact weight-bearing exercise have been shown to be greater when training is started prior to menarche. We hypothesized that significant differences would be apparent in the relationships between bone values and jumping height in favor of the girls’ prior menarche compared to post-menarcheal group. Research aim. The aim of the study was to investigate the relationships between jumping height and bone mineral density (BMD) in pre-menarcheal and post-menarcheal physically active girls. Research  methods.  In  total,  113  adolescent  girls  from  different  competitive  extramural  athletic  programs participated in this study. Femoral neck and lumbar spine BMD were measured. The heights of vertical jumps (i. e. countermovement jump (CMJ) and rebound jumps for 15 (RJ  15 s) and 30 (RJ  30 s) seconds) were obtained.Research results. After adjusting for major confounders (i. e. age, height, and body mass), the height of rebound jumps correlated only with femoral neck BMD and only in pre-menarcheal group (r = 0.37–0.46; p < 0.05). No correlations were found between BMD variables and jumping height in post-menarcheal girls. The height of CMJ did not correlate with measured BMD variables in the studied groups.Discussion and conclusions. Early puberty is an opportune period to increase bone adaptation to mechanical loading due to the velocity of bone growth and endocrine changes at this time. We suggest that powerful repetitive vertical jumping may be more beneficial to bone health compared to single jumping activities in physically active girls prior to menarche rather than after it.Keywords: bone health, vertical jumps, puberty.

In silico modeling of bone adaptation to rest-inserted loading: Strain energy density versus fluid flow as stimulus

2018 ◽  
Vol 446 ◽  
pp. 110-127 ◽  
Author(s):  
Abhishek Kumar Tiwari ◽  
Rakesh Kumar ◽  
Dharmendra Tripathi ◽  
Subham Badhyal
Keyword(s):  
Fluid Flow ◽  
Energy Density ◽  
In Silico ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Bone Adaptation ◽  
In Silico Modeling

scholarly journals Breast cancer–secreted factors perturb murine bone growth in regions prone to metastasis

2021 ◽  
Vol 7 (12) ◽  
pp. eabf2283
Author(s):  
Aaron E. Chiou ◽  
Chuang Liu ◽  
Inés Moreno-Jiménez ◽  
Tengteng Tang ◽  
Wolfgang Wagermaier ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Growth ◽  
Metastatic Tumor ◽  
Bone Adaptation ◽  
Mineral Apposition Rate ◽  
Micro Computed Tomography ◽  
Primary Tumors ◽  
Secreted Factors ◽  
Carbonate Substitution ◽  
Immunocompromised Mice

Breast cancer frequently metastasizes to bone, causing osteolytic lesions. However, how factors secreted by primary tumors affect the bone microenvironment before the osteolytic phase of metastatic tumor growth remains unclear. Understanding these changes is critical as they may regulate metastatic dissemination and progression. To mimic premetastatic bone adaptation, immunocompromised mice were injected with MDA-MB-231–conditioned medium [tumor-conditioned media (TCM)]. Subsequently, the bones of these mice were subjected to multiscale, correlative analysis including RNA sequencing, histology, micro–computed tomography, x-ray scattering analysis, and Raman imaging. In contrast to overt metastasis causing osteolysis, TCM treatment induced new bone formation that was characterized by increased mineral apposition rate relative to control bones, altered bone quality with less matrix and more carbonate substitution, and the deposition of disoriented mineral near the growth plate. Our study suggests that breast cancer–secreted factors may promote perturbed bone growth before metastasis, which could affect initial seeding of tumor cells.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Distraction Osteogenesis in the Treatment of Craniofacial Anomalies: Applications and Outcomes

2020 ◽  
Vol 5 (6) ◽  
pp. 1469-1481 ◽  
Author(s):  
Joseph A. Napoli ◽  
Carrie E. Zimmerman ◽  
Linda D. Vallino
Keyword(s):  
Distraction Osteogenesis ◽  
Bone Growth ◽  
Upper Airway ◽  
Craniofacial Anomalies ◽  
Craniofacial Skeleton ◽  
Facial Skeleton ◽  
Psychosocial Impairment ◽  
And Function ◽  
Correct Structure

Purpose Craniofacial anomalies (CFA) often result in growth abnormalities of the facial skeleton adversely affecting function and appearance. The functional problems caused by the structural anomalies include upper airway obstruction, speech abnormalities, feeding difficulty, hearing deficits, dental/occlusal defects, and cognitive and psychosocial impairment. Managing disorders of the craniofacial skeleton has been improved by the technique known as distraction osteogenesis (DO). In DO, new bone growth is stimulated allowing bones to be lengthened without need for bone graft. The purpose of this clinical focus article is to describe the technique and clinical applications and outcomes of DO in CFA. Conclusion Distraction can be applied to various regions of the craniofacial skeleton to correct structure and function. The benefits of this procedure include improved airway, feeding, occlusion, speech, and appearance, resulting in a better quality of life for patients with CFA.

18F-sodium fluoride bone deposition quantitation with PET in Mice: Variation with age, sex, and circadian rhythm

2020 ◽  
Vol 59 (06) ◽  
pp. 428-437
Author(s):  
Viktoria Dorau-Rutke ◽  
Kai Huang ◽  
Mathias Lukas ◽  
Marc O. Schulze ◽  
Christian Rosner ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Sodium Fluoride ◽  
Bone Growth ◽  
Bone Volume ◽  
Sleep Phase ◽  
Median Percentage ◽  
Bone Uptake ◽  
Pooled Data ◽  
Uptake Studies ◽  
Bone Deposition

Abstract Aim The aim of this study was to establish a data base for normal 18F-sodium fluoride (18F-NaF) bone uptake as a function of age, sex and circadian rhythm in mice. Methods In 12 female (F) and 12 male (M) C57BL/6N mice PET images were acquired 90 min after intravenous injection of 20 MBq 18F-NaF for 30 minutes. Each mouse was imaged in follow-up studies at 1, 3, 6, 13 and 21 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleep phase) as well as during night conditions (awake phase). Bone uptake is described as the median percentage of the injected activity (%IA) and in relation to bone volume (%IA/ml). Results A significant smaller bone volume was found in F (1.79 ml) compared to M (1.99 ml; p < 0.001). In sex-pooled data, highest bone uptake occurred at an age of 1 month (61.1 %IA, 44.5 %IA/ml) with a significant reduction (p < 0.001) at age 3 months (43.6 %IA, 23.6 %IA/ml), followed by an increase between 13 (47.3 %IA, 24.5 %IA/ml) and 21 months (52.2 %IA, 28.1 %IA/ml). F had a significantly higher total uptake (F 48.2 %IA, M 43.8 %IA; p = 0.026) as well as a higher uptake per ml bone tissue (F 27.0 %IA/ml; M 22.4 %IA/ml; p < 0.001). A significant impact of circadian rhythm was only found for F at ages of 3 and 6 months with a higher uptake during the sleep phase. Conclusion Circadian rhythm had a significant impact on uptake only in F of 3 and 6 months. Regarding sex, F showed generally higher uptake rates than M. The highest uptake values were observed during bone growth at age 1 month in both sexes, a second uptake peak occurred in elderly F. Designing future bone uptake studies with M, attention must be paid to age only, while in F circadian rhythm and age must be taken into account.

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