scholarly journals Computational Analysis of Bone Remodeling in the Proximal Tibia Under Electrical Stimulation Considering the Piezoelectric Properties

2021 ◽  
Vol 9 ◽  
Author(s):  
Yogesh Deepak Bansod ◽  
Maeruan Kebbach ◽  
Daniel Kluess ◽  
Rainer Bader ◽  
Ursula van Rienen
Keyword(s):  
Electrical Stimulation ◽  
Bone Density ◽  
Density Distribution ◽  
Bone Remodeling ◽  
Proximal Tibia ◽  
Bone Adaptation ◽  
Reference Stimulus ◽  
Mechanical Loads ◽  
Final Density ◽  
Daily Physical Activities

The piezoelectricity of bone is known to play a crucial role in bone adaptation and remodeling. The application of an external stimulus such as mechanical strain or electric field has the potential to enhance bone formation and implant osseointegration. Therefore, in the present study, the objective is to investigate bone remodeling under electromechanical stimulation as a step towards establishing therapeutic strategies. For the first time, piezoelectric bone remodeling in the human proximal tibia under electro-mechanical loads was analyzed using the finite element method in an open-source framework. The predicted bone density distributions were qualitatively and quantitatively assessed by comparing with the computed tomography (CT) scan and the bone mineral density (BMD) calculated from the CT, respectively. The effect of model parameters such as uniform initial bone density and reference stimulus on the final density distribution was investigated. Results of the parametric study showed that for different values of initial bone density the model predicted similar but not identical final density distribution. It was also shown that higher reference stimulus value yielded lower average bone density at the final time. The present study demonstrates an increase in bone density as a result of electrical stimulation. Thus, to minimize bone loss, for example, due to physical impairment or osteoporosis, mechanical loads during daily physical activities could be partially replaced by therapeutic electrical stimulation.

High Fidelity Computational Model of Bone Remodeling Cellular Mechanisms

2010 ◽  
Author(s):  
Charles L. Penninger ◽  
Andrés Tovar ◽  
Glen L. Niebur ◽  
John E. Renaud
Keyword(s):  
Bone Remodeling ◽  
Computational Models ◽  
Bone Adaptation ◽  
Daily Activities ◽  
High Fidelity ◽  
Mechanical Stimuli ◽  
Cellular Activity ◽  
Cellular Mechanisms ◽  
Mechanical Loads ◽  
Metabolic Activities

One of the most intriguing aspects of bone is its ability to grow, repair damage, adapt to mechanical loads, and maintain mineral homeostasis [1]. It is generally accepted that bone adaptation occurs in response to the mechanical demands of our daily activities; moreover, strain and microdamage have been implicated as potential stimuli that regulate bone remodeling [2]. Computational models have been used to simulate remodeling in an attempt to better understand the metabolic activities which possess the key information of how this process is carried out [3]. At present, the connection between the cellular activity of remodeling and the applied mechanical stimuli is not fully understood. Only a few mathematical models have been formulated to characterize the remolding process in terms of the cellular mechanisms that occur [4,5].

scholarly journals On the effect of antiresorptive drugs on the bone remodeling of the mandible after dental implantation: a mathematical model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehran Ashrafi ◽  
Farzan Ghalichi ◽  
Behnam Mirzakouchaki ◽  
Manuel Doblare
Keyword(s):  
Mathematical Model ◽  
Bone Density ◽  
Bone Remodeling ◽  
Dental Implants ◽  
Implant Design ◽  
Patient Specific ◽  
Dental Implantation ◽  
Antiresorptive Agents ◽  
Antiresorptive Drugs

AbstractBone remodeling identifies the process of permanent bone change with new bone formation and old bone resorption. Understanding this process is essential in many applications, such as optimizing the treatment of diseases like osteoporosis, maintaining bone density in long-term periods of disuse, or assessing the long-term evolution of the bone surrounding prostheses after implantation. A particular case of study is the bone remodeling process after dental implantation. Despite the overall success of this type of implants, the increasing life expectancy in developed countries has boosted the demand for dental implants in patients with osteoporosis. Although several studies demonstrate a high success rate of dental implants in osteoporotic patients, it is also known that the healing time and the failure rate increase, necessitating the adoption of pharmacological measures to improve bone quality in those patients. However, the general efficacy of these antiresorptive drugs for osteoporotic patients is still controversial, requiring more experimental and clinical studies. In this work, we investigate the effect of different doses of several drugs, used nowadays in osteoporotic patients, on the evolution of bone density after dental implantation. With this aim, we use a pharmacokinetic–pharmacodynamic (PK/PD) mathematical model that includes the effect of antiresorptive drugs on the RANK/RANK-L/OPG pathway, as well as the mechano-chemical coupling with external mechanical loads. This mechano-PK/PD model is then used to analyze the evolution of bone in normal and osteoporotic mandibles after dental implantation with different drug dosages. We show that using antiresorptive agents such as bisphosphonates or denosumab increases bone density and the associated mechanical properties, but at the same time, it also increases bone brittleness. We conclude that, despite the many limitations of these very complex models, the one presented here is capable of predicting qualitatively the evolution of some of the main biological and chemical variables associated with the process of bone remodeling in patients receiving drugs for osteoporosis, so it could be used to optimize dental implant design and coating for osteoporotic patients, as well as the drug dosage protocol for patient-specific treatments.

P117. Bone density distribution in the cervical spine: Establishing level specific reference values

2021 ◽  
Vol 21 (9) ◽  
pp. S197-S198
Author(s):  
Francis C. Lovecchio ◽  
Bryan Ang ◽  
Philip Louie ◽  
Chirag Chaudhary ◽  
Sachin Shah ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Bone Density ◽  
Density Distribution ◽  
Reference Values ◽  
Specific Reference

scholarly journals The Benefits of Neuromuscular Electrical Stimulation in the Muscular and Functional Capacity of Patients With Liver Cirrhosis: Protocol for a Randomized Clinical Trial

2018 ◽  
Vol 11 ◽  
pp. 117955221881183
Author(s):  
Carolina Luana de Mello ◽  
Thaís Martins Albanaz da Conceição ◽  
Tarcila Dal Pont ◽  
Catherine Corrêa Peruzzolo ◽  
Mariana Nunes Lúcio ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Pulmonary Function ◽  
Functional Capacity ◽  
Neuromuscular Electrical Stimulation ◽  
Rectus Femoris ◽  
Training Group ◽  
Functional Independence ◽  
Peripheral Muscle ◽  
Ultrasound Evaluation ◽  
Daily Physical Activities

Cirrhosis causes systemic and metabolic changes that culminate in various complications, such as compromised pulmonary function, ascites, hepatic encephalopathy, weight loss, and muscle weakness with significant physical function limitations. Our aim is to evaluate the effects of training with neuromuscular electrical stimulation (NMES) on the muscular and functional capacity of patients with cirrhosis classified as Child-Pugh B and C. A total of 72 patients diagnosed with cirrhosis will be recruited and randomized to perform an NMES protocol for 50 minutes, 3 times a week, for 4 weeks. The evaluations will be performed at the beginning and after 12 sessions, and patients will be submitted to a pulmonary function test, an ultrasound evaluation of the rectus femoris, an evaluation of peripheral muscle strength, a submaximal exercise capacity test associated with an evaluation of peripheral tissue oxygenation, a quality of life evaluation, and orientation about monitoring daily physical activities. The evaluators and patients will be blinded to the allocation of the groups. Training Group will be treated with the following parameters: frequency of 50 Hz, pulse width of 400 μs, rise and fall times of 2 s, and on:off 1:1; Sham Group: 5 Hz, 100 μs, on:off 1:3. The data will be analyzed using the principles of the intention to treat. This study provides health professionals with information on the benefits of this intervention. In this way, we believe that the results of this study could stimulate the use of NMES as a way of rehabilitating patients with more severe cirrhosis, with the objective of improving these patients’ functional independence.

BIOMECHANICAL RATIONALE FOR CHOICE OF CEMENT MANTLE THICKNESS AROUND A FEMORAL STEM

2018 ◽  
Vol 18 (06) ◽  
pp. 1850064
Author(s):  
IEVGEN LEVADNYI ◽  
JAN AWREJCEWICZ ◽  
OLGA SZYMANOWSKA ◽  
DARIUSZ GRZELCZYK ◽  
JOSÉ EDUARDO GUBAUA ◽  
...  
Keyword(s):  
Bone Density ◽  
Femoral Stem ◽  
Peak Stress ◽  
Proximal Part ◽  
Cement Mantle ◽  
Bone Adaptation ◽  
Replacement Surgery ◽  
Hip Replacement Surgery ◽  
High Reduction ◽  
Hip Arthroplasties

The change in mechanical properties of the femoral bone tissue surrounding hip endoprosthesis stems during the post-operative period is one of the causes of implant instability, and the mathematical description of this phenomenon is the subject of much research. In the present study, a model of bone adaptation, based on isotropic Stanford theory, is created for further computer investigation. The results of implementation of such a mathematical model are presented regarding the choice of cement mantle rational thickness in cemented hip arthroplasties. The results show that for cement mantle thicknesses ranging from 1–1.5[Formula: see text]mm, a peak stress value in the proximal part of the mantle exceeds the limit of durability of bone cement. Moreover, results show that high reduction in the bone density of distal and proximal regions was observed in cases of cement mantle thicknesses varying from 1–3[Formula: see text]mm. No significant changes in bone density of the abovementioned regions were obtained for 4[Formula: see text]mm and 5[Formula: see text]mm. The outcome of numerical investigations can be treated as valuable and will lead to the improvement of cemented hip replacement surgery results.

scholarly journals Protective effect ofGlycyrrhiza glabraroots extract on bone mineral density of ovariectomized rats

BioMedicine ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 8 ◽  
Author(s):  
Dimitrios Galanis ◽  
Konstantinos Soultanis ◽  
Pavlos Lelovas ◽  
Alexandros Zervas ◽  
Panagiotis Papadopoulos ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Density ◽  
Protective Effect ◽  
Bone Mineral ◽  
Proximal Tibia ◽  
Glycyrrhiza Glabra ◽  
Ovariectomized Rats ◽  
Mineral Density ◽  
Three Point Bending ◽  
Significant Difference

Objective: The aim of this study was to evaluate the potential effect of the methanolic extract of plantGlycyrrhiza glabraroots on bone mineral density and femoral bone strength of ovariectomized rats.Methods: Thirty 10-month-old Wistar rats were randomly separated into three groups of ten, Control, Ovariectomy and Ovariectomy-plus-Glycyrrhiza in their drinking water. Total and proximal tibial bone mineral density was measured in all groups before ovariectomy (baseline) and after 3 and 6 months post ovariectomy. Three-point-bending of the femurs and uterine weight and histology were examined at the end of the study.Results: No significant difference was noted in bone density percentage change of total tibia from baseline to 3 months between Control and Ovariectomy-plus-Glycyrrhiza groups (+5.31% ± 4.75 and +3.30% ± 6.31 respectively,P = non significant), and of proximal tibia accordingly (+5.58% ± 6.92 and +2.61% ± 13.62,P = non significant) demonstrating a strong osteoprotective effect. There was notable difference in percentage change of total tibia from baseline to 6 months between groups Ovariectomy and Ovariectomy-plus-Glycyrrhiza (−13.03% ± 5.11 and −0.84% ± 7.63 respectively,P < 0.005), and of proximal tibia accordingly (−27.9% ± 3.69 and −0.81% ± 14.85 respectively,P < 0.001), confirming the protective effect ofGlycyrrhiza glabraextract in preserving bone density of the Ovariectomy-plus-Glycyrrhiza group. Three-point-bending did not reveal any statistically significant difference between Ovariectomy and Ovariectomy-plus-Glycyrrhiza groups. Uterine weights of the Ovariectomy-plus-Glycyrrhiza group ranged between the other two groups with no statistically significant difference to each.Conclusions:Glycyrrhiza glabraroot extract notably protected tibial bone mineral density loss in Ovariectomy-plus-Glycyrrhiza rats in comparison with ovariectomized rats, but did not improve biomechanical strength.

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