Journal of the Mechanical Behavior of Biomedical Materials最新文献_第3页

A bioreactor for in vitro studies of lymphatic endothelial cells with simultaneous fluid shear stress and membrane strain

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-31 DOI: 10.1016/j.jmbbm.2025.106909

C. Davis , B. Zambrano-Roman , R. Sridhar , A. Jastram , S. Chakraborty , D. Zawieja , M.R. Moreno

Reproducing the in vivo physiologic conditions and biomechanical environment to stimulate natural growth and behavior of lymphatic endothelial cells (LECs) is critical in studying the lymphatic system and its response to stimuli. In vitro studies that deconstruct the biomechanical environment, e.g. independently incorporate flow-induced shear stress or membrane strain have demonstrated the significance of mechanotransduction in LECs (and vascular endothelial cells). Such studies have facilitated the investigation of intracellular signaling pathways stimulated by a particular mechanical cue but do not accurately reproduce natural physiologic behavior of in vivo LECs given the absence of other natural mechanical cues. In this study, we present a novel experimental device designed to reconstruct the in vivo biomechanical environment, i.e. a device that enables the simultaneous application of flow-induced shear stress and cyclic stretching of LECs in vitro. The device is uniquely capable of simulating physiologically-relevant conditions for lymphatic endothelial cells, such as low-flow, high-strain scenarios. Using this device, we observed that, like vascular ECs, LECs aligned in the direction of fluid shear stress when steady flow was applied. In our case the behavior was observed under conditions closer to the physiological mean flow in the lymphatic vessels than vascular levels of shear stress. When concurrent cyclic stretching was applied, the alignment in the direction of flow and perpendicular to the uniaxial stretch was detected in a substantially shortened timeframe. Additionally, the distribution of alignment angles was more closely clustered around 90° under the flow/stretch scenario after 6 h than the 24 h flow only scenario, perhaps indicating a greater sensitivity to cyclic stretching than to fluid shear stress in the morphological alignment response of LECs. We also observed alignment of cell nuclei and F-actin filaments in Human Dermal Lymphatic Endothelial Cells (HDLECs) after only 6 h of combined flow and stretch. These observations underscore the importance of including both sources of mechanical stress when studying the growth and behavior of LECs.

{"title":"A bioreactor for in vitro studies of lymphatic endothelial cells with simultaneous fluid shear stress and membrane strain","authors":"C. Davis , B. Zambrano-Roman , R. Sridhar , A. Jastram , S. Chakraborty , D. Zawieja , M.R. Moreno","doi":"10.1016/j.jmbbm.2025.106909","DOIUrl":"10.1016/j.jmbbm.2025.106909","url":null,"abstract":"<div><div>Reproducing the <em>in vivo</em> physiologic conditions and biomechanical environment to stimulate natural growth and behavior of lymphatic endothelial cells (LECs) is critical in studying the lymphatic system and its response to stimuli. <em>In vitro</em> studies that deconstruct the biomechanical environment, e.g. independently incorporate flow-induced shear stress or membrane strain have demonstrated the significance of mechanotransduction in LECs (and vascular endothelial cells). Such studies have facilitated the investigation of intracellular signaling pathways stimulated by a particular mechanical cue but do not accurately reproduce natural physiologic behavior of <em>in vivo</em> LECs given the absence of other natural mechanical cues. In this study, we present a novel experimental device designed to reconstruct the <em>in vivo</em> biomechanical environment, i.e. a device that enables the simultaneous application of flow-induced shear stress and cyclic stretching of LECs <em>in vitro</em>. The device is uniquely capable of simulating physiologically-relevant conditions for lymphatic endothelial cells, such as low-flow, high-strain scenarios. Using this device, we observed that, like vascular ECs, LECs aligned in the direction of fluid shear stress when steady flow was applied. In our case the behavior was observed under conditions closer to the physiological mean flow in the lymphatic vessels than vascular levels of shear stress. When concurrent cyclic stretching was applied, the alignment in the direction of flow and perpendicular to the uniaxial stretch was detected in a substantially shortened timeframe. Additionally, the distribution of alignment angles was more closely clustered around 90° under the flow/stretch scenario after 6 h than the 24 h flow only scenario, perhaps indicating a greater sensitivity to cyclic stretching than to fluid shear stress in the morphological alignment response of LECs. We also observed alignment of cell nuclei and F-actin filaments in Human Dermal Lymphatic Endothelial Cells (HDLECs) after only 6 h of combined flow and stretch. These observations underscore the importance of including both sources of mechanical stress when studying the growth and behavior of LECs.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106909"},"PeriodicalIF":3.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of boundary conditions for predicting femoral bone-implant mechanics during gait in the absence of comprehensive medical imaging

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-30 DOI: 10.1016/j.jmbbm.2025.106908

Emmanuel Eghan-Acquah , Alireza Y. Bavil , Laura E. Diamond , Rod Barrett , Christopher P. Carty , Martina Barzan , David Bade , Azadeh Nasseri , David G. Lloyd , David J. Saxby , Stefanie Feih

Finite element analysis (FEA) is nowadays a pivotal tool in orthopaedic research for personalized virtual surgery planning. Despite its widespread use, a comprehensive evaluation of the effect of boundary conditions on the simulation of physiological mechanics in implanted bone is currently lacking. This study assesses the impact of boundary conditions and femur geometry on predicted femur mechanics. It focuses on an isolated implanted femur, partially imaged, from a paediatric patient with femoral varus who underwent a proximal femoral osteotomy. By employing FEA of the femur under motion with loading scenarios informed by personalized neuromusculoskeletal modelling, this study evaluated implant and bone mechanics across three femur model configurations (full-femur, proximal half-femur, and distally synthesized full-femur) with two boundary condition approaches (biomechanical and fixed distal). The biomechanical boundary condition was validated against the gold standard inertia relief method for the natural femur and thereafter exploited as the benchmark against the other implanted femur model configurations. The distally synthesized full-femur with biomechanical boundary conditions performed best and closely predicted bone-implant micromotion (R² = 0.99, nRMSE = 0.3%), risk of implant yield (<1% variance from the benchmark model), and interfragmentary movement (R² = 1, nRMSE = 6%). The half-femur model with biomechanical boundary conditions overpredicted the risk of yield and interfragmentary movements by 17% and 15.8%, respectively. The fixed distal constraint method significantly overestimated the risk of implant yield in both half and synthesized full-femur models by 157% and 170%, respectively. These findings underscore the critical importance of selecting appropriate boundary conditions in the FEA of implanted femur models and advocate for the synthesis of the missing portion of the femur coupled with the biomechanical boundary conditions for more accurate predictions of bone and implant mechanics. Such insights are expected to enhance the physiological plausibility and reliability of orthopaedic research and clinical practices, especially when managing proximal femoral osteotomies.

{"title":"Evaluation of boundary conditions for predicting femoral bone-implant mechanics during gait in the absence of comprehensive medical imaging","authors":"Emmanuel Eghan-Acquah , Alireza Y. Bavil , Laura E. Diamond , Rod Barrett , Christopher P. Carty , Martina Barzan , David Bade , Azadeh Nasseri , David G. Lloyd , David J. Saxby , Stefanie Feih","doi":"10.1016/j.jmbbm.2025.106908","DOIUrl":"10.1016/j.jmbbm.2025.106908","url":null,"abstract":"<div><div>Finite element analysis (FEA) is nowadays a pivotal tool in orthopaedic research for personalized virtual surgery planning. Despite its widespread use, a comprehensive evaluation of the effect of boundary conditions on the simulation of physiological mechanics in implanted bone is currently lacking. This study assesses the impact of boundary conditions and femur geometry on predicted femur mechanics. It focuses on an isolated implanted femur, partially imaged, from a paediatric patient with femoral varus who underwent a proximal femoral osteotomy. By employing FEA of the femur under motion with loading scenarios informed by personalized neuromusculoskeletal modelling, this study evaluated implant and bone mechanics across three femur model configurations (full-femur, proximal half-femur, and distally synthesized full-femur) with two boundary condition approaches (biomechanical and fixed distal). The biomechanical boundary condition was validated against the gold standard inertia relief method for the natural femur and thereafter exploited as the benchmark against the other implanted femur model configurations. The distally synthesized full-femur with biomechanical boundary conditions performed best and closely predicted bone-implant micromotion (R<sup>2</sup> = 0.99, nRMSE = 0.3%), risk of implant yield (<1% variance from the benchmark model), and interfragmentary movement (R<sup>2</sup> = 1, nRMSE = 6%). The half-femur model with biomechanical boundary conditions overpredicted the risk of yield and interfragmentary movements by 17% and 15.8%, respectively. The fixed distal constraint method significantly overestimated the risk of implant yield in both half and synthesized full-femur models by 157% and 170%, respectively. These findings underscore the critical importance of selecting appropriate boundary conditions in the FEA of implanted femur models and advocate for the synthesis of the missing portion of the femur coupled with the biomechanical boundary conditions for more accurate predictions of bone and implant mechanics. Such insights are expected to enhance the physiological plausibility and reliability of orthopaedic research and clinical practices, especially when managing proximal femoral osteotomies.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106908"},"PeriodicalIF":3.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143328668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

What does the slope of stress–stretch curves tell us about vascular tissue response?

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-28 DOI: 10.1016/j.jmbbm.2025.106906

Jia Lu , Ferdinando Auricchio

We examined a group of 50 uniaxial stress–stretch curves obtained from human ascending aortic aneurysm tissues. The curves were believed to be associated with elastic response because the stress is monotonically increasing in all curves, and so is the slope. However, 26 curves exhibit exponential-like slope while the remaining 24 curves have sigmoid slopes. We hypothesized that the slope patterns stemmed from collage waviness distribution. A structural constitutive model was introduced to describe the responses. The model employed a unimodal density function to describe the waviness distribution, from which a two-phase response ensued. In the first phase the slope is quasi-exponential, and in the second phase the slope is sigmoid. The model fitted all 50 curves perfectly well. An exponential model was also introduced for a comparison. The model fitted the curves of quasi-exponential slope generally well, but performed worse over the curves of sigmoid slope. The work suggests that the slope may encode significant information about collagen waviness, and underscores a limitation of exponential-based models.

{"title":"What does the slope of stress–stretch curves tell us about vascular tissue response?","authors":"Jia Lu , Ferdinando Auricchio","doi":"10.1016/j.jmbbm.2025.106906","DOIUrl":"10.1016/j.jmbbm.2025.106906","url":null,"abstract":"<div><div>We examined a group of 50 uniaxial stress–stretch curves obtained from human ascending aortic aneurysm tissues. The curves were believed to be associated with elastic response because the stress is monotonically increasing in all curves, and so is the slope. However, 26 curves exhibit exponential-like slope while the remaining 24 curves have sigmoid slopes. We hypothesized that the slope patterns stemmed from collage waviness distribution. A structural constitutive model was introduced to describe the responses. The model employed a unimodal density function to describe the waviness distribution, from which a two-phase response ensued. In the first phase the slope is quasi-exponential, and in the second phase the slope is sigmoid. The model fitted all 50 curves perfectly well. An exponential model was also introduced for a comparison. The model fitted the curves of quasi-exponential slope generally well, but performed worse over the curves of sigmoid slope. The work suggests that the slope may encode significant information about collagen waviness, and underscores a limitation of exponential-based models.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106906"},"PeriodicalIF":3.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Glass infiltration in an experimental ATZ ceramic composite reinforced with Al2O3 whiskers

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-26 DOI: 10.1016/j.jmbbm.2025.106892

Tiago Moreira Bastos Campos , Ana Carolina da Silva , Bruno Roberto Spirandeli , Edmara Tatiely Pedroso Bergamo , Larissa Marcia Martins Alves , Ernesto Byron Benalcázar Jalkh , Gilmar Patrocínio Thim , Claudinei Santos , Paulo G. Coelho , Estevam Augusto Bonfante

This study evaluated the development and characterization of alumina-toughened zirconia (ATZ) composites containing 10 wt% Al₂O₃ whiskers subjected to the glass infiltration. To obtain ATZ 90/10 composites, the commercial 3Y-TZP powder was mixed with synthesized alumina whiskers and subsequently compacted. Discs (n = 210) were pre-sintered at 1000 °C for 1 h. The infiltration of glass (68SiO₂-11.7Al₂O₃-3CaO-7.3Na₂O-10K₂O) was developed by mixing glass and propylene glycol, which was then applied onto ATZ pre-sintered specimens. For infiltration, the graded discs were divided into two different sintering protocols: protocol 1 (1550 °C for 2 h) and protocol 2 (1350 °C for 1 h followed by 1550 °C for 2 h). As a control group, non-infiltrated specimens were sintered using protocol 1. The specimens were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Hardness, fracture toughness, and biaxial flexural strength tests followed by fractographic analysis were performed. Statistical analyses were conducted using Weibull distribution to calculate the material's modulus (m) and characteristic strength (95% CI), as well as ANOVA tests. High-aspect ratio alumina whiskers (10 μm × 200 nm) were synthesized. While the control group's XRD patterns evidenced only characteristic tetragonal zirconia and α−alumina peaks, the glass-infiltrated groups did not present characteristic peaks of crystalline materials. ATZ with alumina whiskers showed higher fracture toughness and characteristic strength compared to conventional ATZ. Furthermore, glass-infiltration improved the characteristic strength of conventional ATZ with no significant differences observed in the Weibull modulus. For W-G-2, C, and W groups the fractures originated at the zirconia surface, while for C-G-1-, C-G-2, and W-G-1 the origins were inside the ceramic microstructure. In conclusion, the development of ATZ with alumina whiskers increased the biaxial flexural strength and fracture toughness compared to conventional ATZ. The glass gradation significantly improved the characteristic strength of conventional ATZ regardless of the sintering protocol used, whereas it only improved the characteristic strength of whisker-reinforced ATZ when a single sintering was performed. Additionally, the sintering protocol influenced the thickness and amount of glass gradation in the composites.

{"title":"Glass infiltration in an experimental ATZ ceramic composite reinforced with Al2O3 whiskers","authors":"Tiago Moreira Bastos Campos , Ana Carolina da Silva , Bruno Roberto Spirandeli , Edmara Tatiely Pedroso Bergamo , Larissa Marcia Martins Alves , Ernesto Byron Benalcázar Jalkh , Gilmar Patrocínio Thim , Claudinei Santos , Paulo G. Coelho , Estevam Augusto Bonfante","doi":"10.1016/j.jmbbm.2025.106892","DOIUrl":"10.1016/j.jmbbm.2025.106892","url":null,"abstract":"<div><div>This study evaluated the development and characterization of alumina-toughened zirconia (ATZ) composites containing 10 wt% Al<sub>2</sub>O<sub>3</sub> whiskers subjected to the glass infiltration. To obtain ATZ 90/10 composites, the commercial 3Y-TZP powder was mixed with synthesized alumina whiskers and subsequently compacted. Discs (n = 210) were pre-sintered at 1000 °C for 1 h. The infiltration of glass (68SiO<sub>2</sub>-11.7Al<sub>2</sub>O<sub>3</sub>-3CaO-7.3Na<sub>2</sub>O-10K<sub>2</sub>O) was developed by mixing glass and propylene glycol, which was then applied onto ATZ pre-sintered specimens. For infiltration, the graded discs were divided into two different sintering protocols: protocol 1 (1550 °C for 2 h) and protocol 2 (1350 °C for 1 h followed by 1550 °C for 2 h). As a control group, non-infiltrated specimens were sintered using protocol 1. The specimens were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Hardness, fracture toughness, and biaxial flexural strength tests followed by fractographic analysis were performed. Statistical analyses were conducted using Weibull distribution to calculate the material's modulus (<em>m</em>) and characteristic strength (95% CI), as well as ANOVA tests. High-aspect ratio alumina whiskers (10 μm × 200 nm) were synthesized. While the control group's XRD patterns evidenced only characteristic tetragonal zirconia and α−alumina peaks, the glass-infiltrated groups did not present characteristic peaks of crystalline materials. ATZ with alumina whiskers showed higher fracture toughness and characteristic strength compared to conventional ATZ. Furthermore, glass-infiltration improved the characteristic strength of conventional ATZ with no significant differences observed in the Weibull modulus. For W-G-2, C, and W groups the fractures originated at the zirconia surface, while for C-G-1-, C-G-2, and W-G-1 the origins were inside the ceramic microstructure. In conclusion, the development of ATZ with alumina whiskers increased the biaxial flexural strength and fracture toughness compared to conventional ATZ. The glass gradation significantly improved the characteristic strength of conventional ATZ regardless of the sintering protocol used, whereas it only improved the characteristic strength of whisker-reinforced ATZ when a single sintering was performed. Additionally, the sintering protocol influenced the thickness and amount of glass gradation in the composites.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106892"},"PeriodicalIF":3.3,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A bio-lattice deep learning framework for modeling discrete biological materials

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-25 DOI: 10.1016/j.jmbbm.2025.106900

Manik Kumar , Nilay Upadhyay , Shishir Barai , Wesley F. Reinhart , Christian Peco

Biological tissues dynamically adapt their mechanical properties at the microscale in response to stimuli, often governed by discrete interacting mechanisms that dictate the material’s behavior at the macroscopic scale. An approach to model the discrete nature of these elemental units is the Lattice Spring Modeling (LSM). However, the interactions in biological matter can present a high degree of complexity and heterogeneity at the macroscale, posing a computational challenge in multiscale modeling. In this work, we propose a novel machine learning-based multiscale framework that integrates deep neural networks (DNNs), the finite element method (FEM), and a LSM-inspired microstructure description to investigate the behavior of discrete, spatially heterogeneous materials. We develop a versatile, assumption-free lattice framework for interacting discrete units, and derive a consistent multiscale connection with our FEM implementation. A single DNN is trained to learn the constitutive equations of various particle configurations and boundary conditions, enabling rapid response predictions of heterogeneous biological tissues. We demonstrate the effectiveness of our approach with extensive testing, starting with benchmark cases and progressively increasing the complexity of the microstructures. We explored materials ranging from soft to hard inclusions, then combined them to form a macroscopically homogeneous material, a gradient-varying polycrystalline solid, and fully randomized configurations. Our results show that the model accurately captures the material response across these spatially varying structures.

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引用次数: 0

Fracture toughness and subcritical crack growth analysis of high-translucent zirconia prepared by stereolithography-based additive manufacturing

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-24 DOI: 10.1016/j.jmbbm.2025.106917

Li Wang , Kang Wang , Zongdong Hao , Rui Dou , Fangyong Zhu , Yufeng Gao

The objective was to study the subcritical crack growth phenomena and determine the fracture toughness of two yttria-partially-stabilized zirconia ceramics. One of the two materials evaluated was a commercially available 5 mol% yttria partially stabilized zirconia (5Y-PSZ), and the other was an experimental partially stabilized zirconia made from a mixture of 3 mol% and 8 mol% yttria stabilized zirconia powder (3Y+8Y-PSZ), with the final samples prepared by the Stereolithography (SLA) process. The samples in water were tested by three-point bending experiments at different stress rates to obtain Weibull and SCG parameters. The results show that 3Y+8Y-PSZ has higher Weibull modulus(m = 11.54) and characteristic strength(σ₀ = 812.27 MPa) compared to 5Y-PSZ (m = 8.57, σ₀ = 647.25 MPa). SCG parameters n obtained for 5Y-PSZ and 3Y+8Y-PSZ tested in water were 26.03, 37.94, respectively. The strength of 5Y-PSZ and 3Y+8Y-PSZ (P_f = 5%) was reduced by 56.49%, 45.30% after 10 years of simulated use. Regarding the fracture toughness of both materials, 3Y+8Y-PSZ had higher values regardless of the method used to determine it. However, the fitting correction factor of the Vickers indentation method was not applicable to either 5Y-PSZ or 3Y+8Y-PSZ. Determining the SCG parameters of two materials and predicting their lifetimes using constant stress rate testing is an effective way to evaluate materials.

{"title":"Fracture toughness and subcritical crack growth analysis of high-translucent zirconia prepared by stereolithography-based additive manufacturing","authors":"Li Wang , Kang Wang , Zongdong Hao , Rui Dou , Fangyong Zhu , Yufeng Gao","doi":"10.1016/j.jmbbm.2025.106917","DOIUrl":"10.1016/j.jmbbm.2025.106917","url":null,"abstract":"<div><div>The objective was to study the subcritical crack growth phenomena and determine the fracture toughness of two yttria-partially-stabilized zirconia ceramics. One of the two materials evaluated was a commercially available 5 mol% yttria partially stabilized zirconia (5Y-PSZ), and the other was an experimental partially stabilized zirconia made from a mixture of 3 mol% and 8 mol% yttria stabilized zirconia powder (3Y+8Y-PSZ), with the final samples prepared by the Stereolithography (SLA) process. The samples in water were tested by three-point bending experiments at different stress rates to obtain Weibull and SCG parameters. The results show that 3Y+8Y-PSZ has higher Weibull modulus(m = 11.54) and characteristic strength(σ<sub>0</sub> = 812.27 MPa) compared to 5Y-PSZ (m = 8.57, σ<sub>0</sub> = 647.25 MPa). SCG parameters n obtained for 5Y-PSZ and 3Y+8Y-PSZ tested in water were 26.03, 37.94, respectively. The strength of 5Y-PSZ and 3Y+8Y-PSZ (P<sub>f</sub> = 5%) was reduced by 56.49%, 45.30% after 10 years of simulated use. Regarding the fracture toughness of both materials, 3Y+8Y-PSZ had higher values regardless of the method used to determine it. However, the fitting correction factor of the Vickers indentation method was not applicable to either 5Y-PSZ or 3Y+8Y-PSZ. Determining the SCG parameters of two materials and predicting their lifetimes using constant stress rate testing is an effective way to evaluate materials.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106917"},"PeriodicalIF":3.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143082902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomechanical evaluation of implant techniques for ipsilateral femoral neck and shaft fractures: A finite element analysis

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-23 DOI: 10.1016/j.jmbbm.2025.106890

Yukun Xiao , Kui He , Xiaoqi Tan , Daiqing Wei , Jiyuan Yan , Yunkang Yang , Feifan Xiang

Purpose

No consensus has been reached regarding the treatment of ipsilateral femoral neck fractures and femoral shaft fractures (FNF + FSF). This study discusses the stability and differences between multiple single- and dual-implant strategies in the treatment of FNF + FSF and aims to provide a theoretical reference for clinical applications.

Methods

Based on multi-sample finite element analysis, models of basicervical FNF (bFNFs Pauwels III) combined with three different FSFs (proximal (PFSF), middle (MFSF), and distal (DFSF)) were developed. Five implant strategies were established: (A) reconstructive nail (RN), (B) proximal femoral nail antirotation II (PFNA-II), (C) three cannulated compression screws + retrograde intramedullary nail (3CCS + RIN), (D) dynamic hip screw + antirotation screw (DHS + AS) + RIN, and (E) femoral neck system (FNS) + RIN. The biomechanical characteristic of FNF + FSF treated with five strategies were statistically analyzed.

Results

In most cases, there was no significant difference between the single- and dual-implant groups in the FSF gait cycle (at 0° hip joint pressure load or with FNF + MFSF). In other cases, the dual-implant group was predominant. Maximum mean stress of neck-screw: A (235.1 MPa) > B (194.1 MPa) > D (191.5 MPa) > E (181.9 MPa) > C (153.9 MPa) at 30° hip joint loading; A (137.9 MPa) > E (126.3 MPa) > B (105.5 MPa) > D (104.1 MPa) > C (89.30 MPa) at 0°; A (306.3 MPa) > B (261.6 MPa) > D (259.5 MPa) > E (246.2 MPa) > C (217.2 MPa) at −30°. Meanwhile, group C had the lowest fracture interface stress and relative displacement of bFNFs.

Conclusion

Dual-implant strategy for combined fixation, which can effectively strengthen the integral structural stiffness of the femur, is recommended for FNF + FSF. 3CSS and DHS + AS in the dual-implant strategies have better regional stability of bFNFs.

目的对于同侧股骨颈骨折和股骨干骨折（FNF + FSF）的治疗尚未达成共识。方法基于多样本有限元分析，建立了基本股骨颈骨折（bFNFs Pauwels III）与三种不同股骨干骨折（近端（PFSF）、中部（MFSF）和远端（DFSF））相结合的模型。建立了五种植入策略：(A) 重建钉（RN），(B) 股骨近端抗旋转钉 II（PFNA-II），(C) 三枚套管加压螺钉+逆行髓内钉（3CCS + RIN），(D) 动态髋螺钉+抗旋转螺钉（DHS + AS）+ RIN，以及 (E) 股骨颈系统（FNS）+ RIN。结果在大多数情况下，单假体组和双假体组在 FSF 步态周期（髋关节压力负荷为 0°或使用 FNF + MFSF）中没有显著差异。而在其他情况下，双假体组则占优势。颈部螺钉的最大平均应力：A（235.1 MPa）；B（194.1 MPa）；D（191.5 MPa）；E（181.9 MPa）；C（153.9 MPa）；A（137.9 MPa）；E（126.3 MPa）；B（105.5 MPa）；D（104.1 MPa）；C（89.30 MPa）；A（306.3 MPa）；B（261.6 MPa）；D（259.5 MPa）；E（246.2 MPa）；C（217.2 MPa）。同时，C 组的骨折界面应力和 bFNFs 的相对位移最小。双种植策略中的3CSS和DHS+AS具有更好的bFNFs区域稳定性。

{"title":"Biomechanical evaluation of implant techniques for ipsilateral femoral neck and shaft fractures: A finite element analysis","authors":"Yukun Xiao , Kui He , Xiaoqi Tan , Daiqing Wei , Jiyuan Yan , Yunkang Yang , Feifan Xiang","doi":"10.1016/j.jmbbm.2025.106890","DOIUrl":"10.1016/j.jmbbm.2025.106890","url":null,"abstract":"<div><h3>Purpose</h3><div>No consensus has been reached regarding the treatment of ipsilateral femoral neck fractures and femoral shaft fractures (FNF + FSF). This study discusses the stability and differences between multiple single- and dual-implant strategies in the treatment of FNF + FSF and aims to provide a theoretical reference for clinical applications.</div></div><div><h3>Methods</h3><div>Based on multi-sample finite element analysis, models of basicervical FNF (bFNFs Pauwels III) combined with three different FSFs (proximal (PFSF), middle (MFSF), and distal (DFSF)) were developed. Five implant strategies were established: (A) reconstructive nail (RN), (B) proximal femoral nail antirotation II (PFNA-II), (C) three cannulated compression screws + retrograde intramedullary nail (3CCS + RIN), (D) dynamic hip screw + antirotation screw (DHS + AS) + RIN, and (E) femoral neck system (FNS) + RIN. The biomechanical characteristic of FNF + FSF treated with five strategies were statistically analyzed.</div></div><div><h3>Results</h3><div>In most cases, there was no significant difference between the single- and dual-implant groups in the FSF gait cycle (at 0° hip joint pressure load or with FNF + MFSF). In other cases, the dual-implant group was predominant. Maximum mean stress of neck-screw: A (235.1 MPa) > B (194.1 MPa) > D (191.5 MPa) > E (181.9 MPa) > C (153.9 MPa) at 30° hip joint loading; A (137.9 MPa) > E (126.3 MPa) > B (105.5 MPa) > D (104.1 MPa) > C (89.30 MPa) at 0°; A (306.3 MPa) > B (261.6 MPa) > D (259.5 MPa) > E (246.2 MPa) > C (217.2 MPa) at −30°. Meanwhile, group C had the lowest fracture interface stress and relative displacement of bFNFs.</div></div><div><h3>Conclusion</h3><div>Dual-implant strategy for combined fixation, which can effectively strengthen the integral structural stiffness of the femur, is recommended for FNF + FSF. 3CSS and DHS + AS in the dual-implant strategies have better regional stability of bFNFs.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106890"},"PeriodicalIF":3.3,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Soft tissue-like coupling materials for in vitro acoustic emission studies in total hip arthroplasty

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-23 DOI: 10.1016/j.jmbbm.2025.106905

Magnus Reulbach , Magdalena Meyer zu Vilsendorf , Sinan Yarcu , Bernd-Arno Behrens , Sven Hübner , Eike Jakubowitz

In hip arthroplasty, relative movements between the femoral stem and bone can lead to implant loosening, resulting in extensive bone loss. Acoustic emission (AE) analysis is a promising technique for a nondestructive and noninvasive detection of these relative movements. To develop such a detection method, in vitro investigations using piezoelectric AE sensors on implant stems in artificial or human femora are required to characterize the AE signals induced by loosening. This study aims to identify suitable coupling materials to bridge the gap between the planar AE-sensor surface and the exposed freeform surface of the femur. Four coupling materials, both synthetic and natural, with acoustic properties similar to human soft tissue were investigated for signal attenuation and repeatability between tests. The synthetic materials demonstrated better inter-sample repeatability. One synthetic material exhibited higher flexibility, enabling better adaptation to the sensor and resulting in significantly lower signal attenuation.

{"title":"Soft tissue-like coupling materials for in vitro acoustic emission studies in total hip arthroplasty","authors":"Magnus Reulbach , Magdalena Meyer zu Vilsendorf , Sinan Yarcu , Bernd-Arno Behrens , Sven Hübner , Eike Jakubowitz","doi":"10.1016/j.jmbbm.2025.106905","DOIUrl":"10.1016/j.jmbbm.2025.106905","url":null,"abstract":"<div><div>In hip arthroplasty, relative movements between the femoral stem and bone can lead to implant loosening, resulting in extensive bone loss. Acoustic emission (AE) analysis is a promising technique for a nondestructive and noninvasive detection of these relative movements. To develop such a detection method, <em>in vitro</em> investigations using piezoelectric AE sensors on implant stems in artificial or human femora are required to characterize the AE signals induced by loosening. This study aims to identify suitable coupling materials to bridge the gap between the planar AE-sensor surface and the exposed freeform surface of the femur. Four coupling materials, both synthetic and natural, with acoustic properties similar to human soft tissue were investigated for signal attenuation and repeatability between tests. The synthetic materials demonstrated better inter-sample repeatability. One synthetic material exhibited higher flexibility, enabling better adaptation to the sensor and resulting in significantly lower signal attenuation.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106905"},"PeriodicalIF":3.3,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of head size, head material, and radiation dose on the repeatability of CT-RSA measurements of femoral head penetration

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-22 DOI: 10.1016/j.jmbbm.2025.106907

Jennifer S. Polus , Bart L. Kaptein , Brent A. Lanting , Matthew G. Teeter

Background

The risk of early revision of total hip arthroplasty (THA) for polyethylene wear is now low, but there remains a need to perform wear measurements in patients for clinical surveillance. The gold standard of wear measurements has been radiostereometric analysis (RSA), which has limited availability. The use of computed tomography (CT) to perform THA wear measurement was described a decade ago and found to have acceptable accuracy and precision, but high radiation dose was a concern. Additionally, the use of larger femoral head sizes and ceramic femoral heads has risen in the past decade. The objectives of the study were to determine the effect of femoral head size, femoral head material, and lowered radiation dose on femoral head penetration measurement repeatability.

Methods

A cadaveric hip was implanted with a cementless THA implant system. CT scans were acquired at a conventional radiation dose and at a reduced dose and repeated for a 32 mm and 36 mm cobalt-chromium femoral heads and a 32 mm ceramic femoral head. Apparent translation of the femoral head versus the acetabular cup was measured between the repeated scans using a CT-RSA software, where deviations from zero indicated measurement precision.

Results

The mean and standard deviation of translations in all planes was <0.200 mm. There was no effect for 3D translation of increasing cobalt-chromium head size (p = 0.2252). Cobalt-chromium heads had superior repeatability compared to ceramic heads at reduced dose (p = 0.022), but not at conventional dose (p = 0.1265). Further, superior repeatability was achieved with the reduced dose scan for the cobalt-chromium head (p = 0.0058), however there was no difference between doses for the ceramic head (p = 0.8148).

Discussion

CT-based wear measurement repeatability is excellent and consistent with prior literature even when implementing a larger femoral head, a ceramic femoral head, or reducing radiation dose to 25% of a conventional clinical scan.

{"title":"Effect of head size, head material, and radiation dose on the repeatability of CT-RSA measurements of femoral head penetration","authors":"Jennifer S. Polus , Bart L. Kaptein , Brent A. Lanting , Matthew G. Teeter","doi":"10.1016/j.jmbbm.2025.106907","DOIUrl":"10.1016/j.jmbbm.2025.106907","url":null,"abstract":"<div><h3>Background</h3><div>The risk of early revision of total hip arthroplasty (THA) for polyethylene wear is now low, but there remains a need to perform wear measurements in patients for clinical surveillance. The gold standard of wear measurements has been radiostereometric analysis (RSA), which has limited availability. The use of computed tomography (CT) to perform THA wear measurement was described a decade ago and found to have acceptable accuracy and precision, but high radiation dose was a concern. Additionally, the use of larger femoral head sizes and ceramic femoral heads has risen in the past decade. The objectives of the study were to determine the effect of femoral head size, femoral head material, and lowered radiation dose on femoral head penetration measurement repeatability.</div></div><div><h3>Methods</h3><div>A cadaveric hip was implanted with a cementless THA implant system. CT scans were acquired at a conventional radiation dose and at a reduced dose and repeated for a 32 mm and 36 mm cobalt-chromium femoral heads and a 32 mm ceramic femoral head. Apparent translation of the femoral head versus the acetabular cup was measured between the repeated scans using a CT-RSA software, where deviations from zero indicated measurement precision.</div></div><div><h3>Results</h3><div>The mean and standard deviation of translations in all planes was <0.200 mm. There was no effect for 3D translation of increasing cobalt-chromium head size (p = 0.2252). Cobalt-chromium heads had superior repeatability compared to ceramic heads at reduced dose (p = 0.022), but not at conventional dose (p = 0.1265). Further, superior repeatability was achieved with the reduced dose scan for the cobalt-chromium head (p = 0.0058), however there was no difference between doses for the ceramic head (p = 0.8148).</div></div><div><h3>Discussion</h3><div>CT-based wear measurement repeatability is excellent and consistent with prior literature even when implementing a larger femoral head, a ceramic femoral head, or reducing radiation dose to 25% of a conventional clinical scan.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106907"},"PeriodicalIF":3.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143043957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced mechanical properties and in vitro bioactivity of silicon nitride ceramics with SiO2, Y2O3, and Al2O3 as sintering aids

IF 3.3 2区医学 Q2 ENGINEERING, BIOMEDICAL

Journal of the Mechanical Behavior of Biomedical Materials

Pub Date : 2025-01-20 DOI: 10.1016/j.jmbbm.2025.106901

Yongning Han , Wenying Zhou , Jian Li , Zhuoqun Han , Lunan Bi , Zheng Zhang , Yang Wang , Ling Li , Degang Zhao

Silicon nitride (Si₃N₄) ceramics exhibit excellent mechanical properties and biocompatibility, making them highly suitable for biomedical applications, particularly in implants. In this study, the mechanical properties and bioactivity of Si₃N₄ ceramics with varying amounts of Y₂O₃-Al₂O₃-SiO₂ sintering aids were investigated. Increasing the sintering additive content from 4 wt% to 8 wt% substantially improved the bulk density of the ceramics, leading to notable enhancements in mechanical properties. These included a Vickers hardness increase to 10.07 GPa, a flexural strength increase to 605 MPa, and a fracture toughness increase to 2.43 MPa m^1/2. The optimal combination of mechanical properties was achieved with 8 wt% sintering additives due to the higher aspect ratio and lower porosity. After immersion in simulated body fluid (SBF), the surface of the Si₃N₄ ceramics was coated with a Ca and P-rich layer, morphologically similar to hydroxyapatite. The layer formation was facilitated by the presence of SiO₂, which promoted hydroxyapatite nucleation and growth, as well as the rapid release of Ca²⁺ ions and the sustained stability of the apatite layer.

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引用次数: 0