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Jia T, Guines D, Gordin DM, Leotoing L, Gloriant T. Finite element analysis of a low modulus Ti-20Zr-3Mo-3Sn alloy designed to reduce the stress shielding effect of a hip prosthesis. J Mech Behav Biomed Mater 2024; 157:106640. [PMID: 38917558 DOI: 10.1016/j.jmbbm.2024.106640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 06/27/2024]
Abstract
After total hip arthroplasty, the stress shielding effect can occur due to the difference of stiffness between the metallic alloy of the stems and the host bone, which may cause a proximal bone loss. To overcome this problem, a low-modulus metastable β Ti-20Zr-3Mo-3Sn alloy composition has recently been designed to be potentially used for the cementless femoral hip stems. After having verified experimentally that the β alloy has a low modulus of around 50 GPa, a finite element analysis was performed on a Ti-20Zr-3Mo-3Sn alloy hip prosthesis model to evaluate the influence of a reduced modulus on stress shielding and stress fields in both stem and bone compared with the medical grade Ti-6Al-4V alloy whose elastic modulus reached 110 GPa. Our results show that the Ti-20Zr-3Mo-3Sn stem with low elastic modulus can effectively reduce the total stress shielding by 45.5% compared to the common Ti-6Al-4V prosthesis. Moreover, it is highlighted that the material elasticity affects the stress distribution in the implant, especially near the bone-stem interfaces.
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Affiliation(s)
- Tianyu Jia
- University of Rennes, INSA Rennes, CNRS UMR 6226 ISCR, 35000, Rennes, France
| | - Dominique Guines
- University of Rennes, INSA Rennes, LGCGM, EA 3913, 35000, Rennes, France
| | | | - Lionel Leotoing
- University of Rennes, INSA Rennes, LGCGM, EA 3913, 35000, Rennes, France
| | - Thierry Gloriant
- University of Rennes, INSA Rennes, CNRS UMR 6226 ISCR, 35000, Rennes, France.
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2
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Hetreau C, Mischler D, Schlatter J, Valenti A, Ernst M, Varga P, Schwarzenberg P. Longitudinal CT-based finite element analyses provide objective fracture healing measures in an ovine tibia model. J Orthop Res 2024; 42:1762-1770. [PMID: 38483000 DOI: 10.1002/jor.25838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 02/20/2024] [Accepted: 02/26/2024] [Indexed: 07/04/2024]
Abstract
Measuring the healing status of a bone fracture is important to determine the clinical care a patient receives. Implantable devices can directly and continuously assess the healing status of fracture fixation constructs, while subject-specific virtual biomechanical tests can noninvasively determine callus structural integrity at single time points. Despite their potential for objectification, both methods are not yet integrated into clinical practice with further evidence of their benefits required. This study correlated continuous data from an implantable sensor assessing healing status through implant load monitoring with computer tomography (CT) based longitudinal finite element (FE) simulations in a large animal model. Eight sheep were part of a previous preclinical study utilizing a tibial osteotomy model and equipped with such a sensor. Sensor signal was collected over several months, and CT scans were acquired at six interim time points. For each scan, two FE analyses were performed: a virtual torsional rigidity test of the bone and a model of the bone-implant construct with the sensor. The longitudinal simulation results were compared to the sensor data at corresponding time points and a cohort-specific empirical healing rule was employed. Healing status predicted by both in silico simulations correlated significantly with the sensor data at corresponding time points and correctly identified a delayed and a nonunion in the cohort. The methodology is readily translatable with the potential to be applied to further preclinical or clinical cohorts to find generalizable healing criteria. Virtual mechanical tests can objectively measure fracture healing progressing using longitudinal CT scans.
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Affiliation(s)
| | | | | | | | | | - Peter Varga
- AO Research Institute Davos, Davos, Switzerland
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3
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Ghandour S, Christie I, Öhman Mägi C, Persson C. Quasi-static and dynamic mechanical properties of a linoleic acid-modified, low-modulus bone cement for spinal applications. OPEN RESEARCH EUROPE 2024; 3:203. [PMID: 39185085 PMCID: PMC11344196 DOI: 10.12688/openreseurope.16683.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/15/2024] [Indexed: 08/27/2024]
Abstract
Background Polymethylmethacrylate (PMMA) bone cement is extensively used in spinal procedures such as vertebroplasty and kyphoplasty, while its use in percutaneous cement discoplasty (PCD) is not yet widely spread. A main issue for both application sites, vertebra and disc, is the mismatch in stiffness between cement and bone, potentially resulting in adjacent vertebral fractures and adjacent segment disease. Tailoring the cement modulus using additives is hence an interesting strategy. However, there is a lack of data on the tensile and tension-compression fatigue properties of these cements, relevant to the newly researched indication of PCD. Method A commercial PMMA cement (VS) was modified with 12%vol of linoleic acid (VSLA) and tested for quasi-static tensile properties. Additionally, tension-compression fatigue testing with amplitudes ranging from +/-5MPa to +/-7MPa and +/-9MPa was performed, and a Weibull three-parameter curve fit was used to calculate the fatigue parameters. Results Quasi-static testing revealed a significant reduction in VSLA's Young's Modulus (E=581.1±126.4MPa) compared to the original cement (E=1478.1±202.9MPa). Similarly, the ultimate tensile stress decreased from 36.6±1.5MPa to 11.6±0.8MPa. Thus, VSLA offers improved compatibility with trabecular bone properties. Fatigue testing of VSLA revealed that as the stress amplitude increased the Weibull mean number decreased from 3591 to 272 and 91 cycles, respectively. In contrast, the base VS cement reached run-out at the highest stress amplitude. However, the lowest stress amplitude used exceeds the pressures recorded in the disc in vivo, and VSLA displayed a similar fatigue life range to that of the annulus fibrosis tissue. Conclusions While the relevance of fully reversed tension-compression fatigue testing can be debated for predicting cement performance in certain spinal applications, the results of this study can serve as a benchmark for comparison of low-modulus cements for the spine. Further investigations are necessary to assess the clinical feasibility and effectiveness of these cements.
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Affiliation(s)
- Salim Ghandour
- Division of Biomedical Engineering, Department of Materials Science and Engineering, Uppsala University, Uppsala, Uppsala County, 75121, Sweden
| | - Iain Christie
- Division of Biomedical Engineering, Department of Materials Science and Engineering, Uppsala University, Uppsala, Uppsala County, 75121, Sweden
- Division of Applied Materials Science, Department of Materials Science and Engineering, Uppsala University, Uppsala, Uppsala County, 75121, Sweden
| | - Caroline Öhman Mägi
- Division of Applied Materials Science, Department of Materials Science and Engineering, Uppsala University, Uppsala, Uppsala County, 75121, Sweden
| | - Cecilia Persson
- Division of Biomedical Engineering, Department of Materials Science and Engineering, Uppsala University, Uppsala, Uppsala County, 75121, Sweden
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4
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Quevedo Gonzalez FJ, Lipman JD, Sculco PK, Sculco TP, De Martino I, Wright TM. An Anterior Spike Decreases Bone-Implant Micromotion in Cementless Tibial Baseplates for Total Knee Arthroplasty: A Biomechanical Study. J Arthroplasty 2024; 39:1323-1327. [PMID: 38000515 DOI: 10.1016/j.arth.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Cementless tibial baseplates in total knee arthroplasty include fixation features (eg, pegs, spikes, and keels) to ensure sufficient primary bone-implant stability. While the design of these features plays a fundamental role in biologic fixation, the effectiveness of anterior spikes in reducing bone-implant micromotion remains unclear. Therefore, we asked: Can an anterior spike reduce the bone-implant micromotion of cementless tibial implants? METHODS We performed computational finite element analyses on 13 tibiae using the computed tomography scans of patients scheduled for primary total knee arthroplasty. The tibiae were virtually implanted with a cementless tibial baseplate with 2 designs of fixation of the baseplate: 2 pegs and 2 pegs with an anterior spike. We compared the bone-implant micromotion under the most demanding loads from stair ascent between both designs. RESULTS Both fixation designs had peak micromotion at the anterior-lateral edge of the baseplate. The design with 2 pegs and an anterior spike had up to 15% lower peak micromotion and up to 14% more baseplate area with micromotions below the most conservative threshold for ingrowth, 20 μm, than the design with only 2 pegs. The greatest benefit of adding an anterior spike occurred for subjects who had the smallest area of tibial bone below the 20 μm threshold (ie, most at risk for failure to achieve bone ingrowth). CONCLUSIONS An anteriorly placed spike for cementless tibial baseplates with 2 pegs can help decrease the bone-implant micromotion during stair ascent, especially for subjects with increased bone-implant micromotion and risk for bone ingrowth failure.
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Affiliation(s)
| | - Joseph D Lipman
- Department of Biomechanics, Hospital for Special Surgery, New York
| | - Peter K Sculco
- Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, New York
| | - Thomas P Sculco
- Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, New York
| | - Ivan De Martino
- Department of Geriatric Science and Orthopaedics, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Timothy M Wright
- Department of Biomechanics, Hospital for Special Surgery, New York
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5
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Baleani M, Erani P, Acciaioli A, Schileo E. Tensile Yield Strain of Human Cortical Bone from the Femoral Diaphysis Is Constant among Healthy Adults and across the Anatomical Quadrants. Bioengineering (Basel) 2024; 11:395. [PMID: 38671816 PMCID: PMC11048186 DOI: 10.3390/bioengineering11040395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
The literature suggests that the yield strain of cortical bone is invariant to its stiffness (elastic modulus) and strength (yield stress). However, data about intra-individual variations, e.g., the influence of different collagen/mineral organisations observed in bone aspects withstanding different habitual loads, are lacking. The hypothesis that the yield strain of human cortical bone tissue, retrieved from femoral diaphyseal quadrants subjected to different habitual loads, is invariant was tested. Four flat dumbbell-shaped specimens were machined from each quadrant of the proximal femoral diaphysis of five adult donors for a total of 80 specimens. Two extensometers attached to the narrow specimen region were used to measure deformation during monotonic tensile testing. The elastic modulus (linear part of the stress-strain curve) and yield strain/stress at a 0.2% offset were obtained. Elastic modulus and yield stress values were, respectively, in the range of 12.2-20.5 GPa and 75.9-136.6 MPa and exhibited a positive linear correlation. All yield strain values were in the narrow range of 0.77-0.87%, regardless of the stiffness and strength of the tissue and the anatomical quadrant. In summary, the results corroborate the hypothesis that tensile yield strain in cortical bone is invariant, irrespective also of the anatomical quadrant. The mean yield strain value found in this study is similar to what was reported by inter-species and evolution studies but slightly higher than previous reports in humans, possibly because of the younger age of our subjects. Further investigations are needed to elucidate a possible dependence of yield strain on age.
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Affiliation(s)
- Massimiliano Baleani
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Paolo Erani
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Alice Acciaioli
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy; (P.E.); (A.A.)
| | - Enrico Schileo
- Laboratorio di Bioingegneria Computazionale, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy;
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6
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Zhu Z, Yang Y, Li L, Zhu SJ, Zhang L. A probabilistic approach for assessing the mechanical performance of intertrochanteric fracture stabilized with proximal femoral nail antirotation. PLoS One 2024; 19:e0299996. [PMID: 38603691 PMCID: PMC11008846 DOI: 10.1371/journal.pone.0299996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 02/19/2024] [Indexed: 04/13/2024] Open
Abstract
Maintaining post-operative mechanical stability is crucial for successfully healing intertrochanteric fractures treated with the Proximal Femoral Nail Antirotation (PFNA) system. This stability is primarily dependent on the bone mineral density (BMD) and strain on the fracture. Current PFNA failure analyses often overlook the uncertainties related to BMD and body weight (BW). Therefore, this study aimed to develop a probabilistic model using finite element modeling and engineering reliability analysis to assess the post-operative performance of PFNA under various physiological loading conditions. The model predictions were validated through a series of experimental test. The results revealed a negative nonlinear relationship between the BMD and compressive strain. Conversely, the BW was positively and linearly correlated with the compressive strain. Importantly, the compressive strain was more sensitive to BW than to BMD when the BMD exceeded 0.6 g/cm3. Potential trabecular bone compression failure is also indicated if BMD is equal to or below 0.15 g/cm3 and BW increases to approximately 2.5 times the normal or higher. This study emphasizes that variations in the BMD significantly affect the probability of failure of a PFNA system. Thus, careful planning of post-operative physical therapy is essential. For patients aged > 50 years restrictions on high-intensity activities are advised, while limiting strenuous movements is recommended for those aged > 65 years.
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Affiliation(s)
- Zhiqi Zhu
- Department of Orthopedics, Longgang District People’s Hospital of Shenzhen, Guangdong, P. R. China
| | - Yi Yang
- Department of Infrastructure Engineering, The University of Melbourne, Victoria, Australia
| | - Lunjian Li
- Department of Infrastructure Engineering, The University of Melbourne, Victoria, Australia
| | - Shuang Jie Zhu
- Department of Mechanical and Product Design Engineering, Swinburne University of Technology, Victoria, Australia
| | - Lihai Zhang
- Department of Infrastructure Engineering, The University of Melbourne, Victoria, Australia
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7
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Ceddia M, Lamberti L, Trentadue B. FEA Comparison of the Mechanical Behavior of Three Dental Crown Materials: Enamel, Ceramic, and Zirconia. MATERIALS (BASEL, SWITZERLAND) 2024; 17:673. [PMID: 38591528 PMCID: PMC10856216 DOI: 10.3390/ma17030673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/24/2024] [Accepted: 01/27/2024] [Indexed: 04/10/2024]
Abstract
The restoration of endodontically treated teeth is one of the main challenges of restorative dentistry. The structure of the tooth is a complex assembly in which the materials that make it up, enamel and dentin, have very different mechanical behaviors. Therefore, finding alternative replacement materials for dental crowns in the area of restorative care isa highly significant challenge, since materials such as ceramic and zirconia have very different stress load resistance values. The aim of this study is to assess which material, either ceramic or zirconia, optimizes the behavior of a restored tooth under various typical clinical conditions and the masticatory load. A finite element analysis (FEA) framework is developed for this purpose. The 3D model of the restored tooth is input into the FEA software (Ansys Workbench R23)and meshed into tetrahedral elements. The presence of masticatory forces is considered: in particular, vertical, 45° inclined, and horizontal resultant forces of 280 N are applied on five contact points of the occlusal surface. The numerical results show that the maximum stress developed in the restored tooth including a ceramic crown and subject to axial load is about 39.381 MPa, which is rather close to the 62.32 MPa stress computed for the natural tooth; stresses of about 18 MPa are localized at the roots of both crown materials. In the case of the zirconia crown, the stresses are much higher than those in the ceramic crown, except for the 45° load direction, while, for the horizontal loads, the stress peak in the zirconia crown is almost three times as large as its counterpart in the ceramic crown (i.e., 163.24 MPa vs. 56.114 MPa, respectively). Therefore, the zirconia crown exhibits higher stresses than enamel and ceramic that could increase in the case of parafunctions, such as bruxism. The clinician's choice between the two materials should be evaluated based on the patient's medical condition.
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Affiliation(s)
| | - Luciano Lamberti
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, 70125 Bari, Italy; (M.C.); (B.T.)
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8
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Zhang C, Wen P, Xu Y, Fu Z, Ren G. Exploring Advanced Functionalities of Carbon Fiber-Graded PEEK Composites as Bone Fixation Plates Using Finite Element Analysis. MATERIALS (BASEL, SWITZERLAND) 2024; 17:414. [PMID: 38255583 PMCID: PMC10817601 DOI: 10.3390/ma17020414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024]
Abstract
This study aims to address the challenges associated with conventional metallic bone fixation plates in biomechanical applications, such as stainless steel and titanium alloys, including stress shielding, allergic reactions, corrosion resistance, and interference with medical imaging. The use of materials with a low elastic modulus is regarded as an effective approach to overcome these problems. In this study, the impact of different types of chopped carbon fiber-reinforced polyether ether ketone (CCF/PEEK) functionally graded material (FGM) bone plates on stress shielding under static and instantaneous dynamic loading was explored using finite element analysis (FEA). The FGM bone plate models were established using ABAQUS and the user's subroutine USDFLD and VUSDFLD, and each model was established with an equivalent overall elastic modulus and distinctive distributions. The results revealed that all FGM bone plates exhibited lower stress shielding effects compared to metal bone plates. Particularly, the FGM plate with an elastic modulus gradually increased from the centre to both sides and provided maximum stress stimulation and the most uniform stress distribution within the fractured area. These findings offer crucial insights for designing implantable medical devices that possess enhanced mechanical adaptability.
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Affiliation(s)
- Chenggong Zhang
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK;
| | - Pihua Wen
- Institute of Aeronautics and Astronautics, School of Infrastructure Engineering, Nanchang University, Nanchang 330031, China
| | - Yigeng Xu
- School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK43 0AL, UK;
| | - Zengxiang Fu
- Faculty of Life Science, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Guogang Ren
- School of Physics, Engineering and Computer Science, University of Hertfordshire, Hatfield AL10 9AB, UK
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Mavrodontis II, Trikoupis IG, Kontogeorgakos VA, Savvidou OD, Papagelopoulos PJ. Point-of-Care Orthopedic Oncology Device Development. Curr Oncol 2023; 31:211-228. [PMID: 38248099 PMCID: PMC10814108 DOI: 10.3390/curroncol31010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/08/2023] [Accepted: 12/26/2023] [Indexed: 01/23/2024] Open
Abstract
BACKGROUND The triad of 3D design, 3D printing, and xReality technologies is explored and exploited to collaboratively realize patient-specific products in a timely manner with an emphasis on designs with meta-(bio)materials. METHODS A case study on pelvic reconstruction after oncological resection (osteosarcoma) was selected and conducted to evaluate the applicability and performance of an inter-epistemic workflow and the feasibility and potential of 3D technologies for modeling, optimizing, and materializing individualized orthopedic devices at the point of care (PoC). RESULTS Image-based diagnosis and treatment at the PoC can be readily deployed to develop orthopedic devices for pre-operative planning, training, intra-operative navigation, and bone substitution. CONCLUSIONS Inter-epistemic symbiosis between orthopedic surgeons and (bio)mechanical engineers at the PoC, fostered by appropriate quality management systems and end-to-end workflows under suitable scientifically amalgamated synergies, could maximize the potential benefits. However, increased awareness is recommended to explore and exploit the full potential of 3D technologies at the PoC to deliver medical devices with greater customization, innovation in design, cost-effectiveness, and high quality.
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Affiliation(s)
- Ioannis I. Mavrodontis
- First Department of Orthopaedic Surgery, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (I.G.T.); (V.A.K.); (O.D.S.); (P.J.P.)
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10
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Kovács K, Váncsa S, Agócs G, Harnos A, Hegyi P, Weninger V, Baross K, Kovács B, Soós G, Kocsis G. Anisotropy, Anatomical Region, and Additional Variables Influence Young's Modulus of Bone: A Systematic Review and Meta-Analysis. JBMR Plus 2023; 7:e10835. [PMID: 38130752 PMCID: PMC10731124 DOI: 10.1002/jbm4.10835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/09/2023] [Accepted: 09/25/2023] [Indexed: 12/23/2023] Open
Abstract
The importance of finite element analysis (FEA) is growing in orthopedic research, especially in implant design. However, Young's modulus (E) values, one of the most fundamental parameters, can range across a wide scale. Therefore, our study aimed to identify factors influencing E values in human bone specimens. We report our systematic review and meta-analysis based on the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline. We conducted the analysis on November 21, 2021. We included studies investigating healthy human bone specimens and reported on E values regarding demographic data, specimen characteristics, and measurement specifics. In addition, we included study types reporting individual specimen measurements. From the acquired data, we created a cohort in which we performed an exploratory data analysis that included the explanatory variables selected by random forest and regression trees methods, and the comparison of groups using independent samples Welch's t test. A total of 756 entries were included from 48 articles. Eleven different bones of the human body were included in these articles. The range of E values is between 0.008 and 33.7 GPa. The E values were most heavily influenced by the cortical or cancellous type of bone tested. Measuring method (compression, tension, bending, and nanoindentation), the anatomical region within a bone, the position of the bone within the skeleton, and the bone specimen size had a decreasing impact on the E values. Bone anisotropy, specimen condition, patient age, and sex were selected as important variables considering the value of E. On the basis of our results, E values of a bone change with bone characteristics, measurement techniques, and demographic variables. Therefore, the evaluation of FEA should be performed after the standardization of in vitro measurement protocol. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Krisztián Kovács
- Department of OrthopaedicsSemmelweis UniversityBudapestHungary
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
| | - Szilárd Váncsa
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
- Institute for Translational Medicine, Szentágothai Research Centre, Medical SchoolUniversity of PécsPécsHungary
- Division of Pancreatic Diseases, Heart and Vascular CenterSemmelweis UniversityBudapestHungary
| | - Gergely Agócs
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
| | - Andrea Harnos
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
- Department of BiostatisticsUniversity of Veterinary MedicineBudapestHungary
| | - Péter Hegyi
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
- Institute for Translational Medicine, Szentágothai Research Centre, Medical SchoolUniversity of PécsPécsHungary
- Division of Pancreatic Diseases, Heart and Vascular CenterSemmelweis UniversityBudapestHungary
| | - Viktor Weninger
- Department of OrthopaedicsSemmelweis UniversityBudapestHungary
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
| | - Katinka Baross
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
| | - Bence Kovács
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
| | - Gergely Soós
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
| | - György Kocsis
- Department of OrthopaedicsSemmelweis UniversityBudapestHungary
- Centre for Translational MedicineSemmelweis UniversityBudapestHungary
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11
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Inglis B, Grumbles D, Dailey HL. Dual-zone material assignment method for correcting partial volume effects in image-based bone models. Comput Methods Biomech Biomed Engin 2023; 26:1431-1442. [PMID: 36062947 DOI: 10.1080/10255842.2022.2119383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/18/2022] [Accepted: 08/26/2022] [Indexed: 11/03/2022]
Abstract
In image-based finite element analysis of bone, partial volume effects (PVEs) arise from image blur at tissue boundaries and as a byproduct of geometric reconstruction and meshing during model creation. In this study, we developed and validated a material assignment approach to mitigate partial volume effects. Our validation data consisted of physical torsion testing of intact tibiae from N = 20 Swiss alpine sheep. We created finite element models from micro-CT scans of these tibiae using three popular element types (10-node tetrahedral, 8-node hexahedral, and 20-node hexahedral). Without partial volume management, the models over-predicted the torsional rigidity compared to physical biomechanical tests. To address this problem, we implemented a dual-zone material model to treat elements that overlap low-density surface voxels as soft tissue rather than bone. After in situ inverse optimization, the dual-zone material model produced strong correlations and high absolute agreement between the virtual and physical tests. This suggests that with appropriate partial volume management, virtual mechanical testing can be a reliable surrogate for physical biomechanical testing. For maximum flexibility in partial volume management regardless of element type, we recommend the use of the following dual-zone material model for ovine tibiae: soft-tissue cutoff density of 665 mgHA/cm3 with a soft tissue modulus of 50 MPa (below cutoff) and a density-modulus conversion slope of 10,225 MPa-cm3/mgHA for bone (above cutoff).
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Affiliation(s)
- Brendan Inglis
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pennsylvania, USA
| | - Daniel Grumbles
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pennsylvania, USA
| | - Hannah L Dailey
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pennsylvania, USA
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12
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Kurz S, Gebhardt M, Grundmann F, Heyde CE, Steinke H. Approach to standardized material characterization of the human lumbopelvic system-Specification, preparation and storage. PLoS One 2023; 18:e0289482. [PMID: 37535581 PMCID: PMC10399898 DOI: 10.1371/journal.pone.0289482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 07/19/2023] [Indexed: 08/05/2023] Open
Abstract
The complexity of the osseo-ligamentous lumbopelvic system has made it difficult to perform both, the overall preparation as well as specimen harvesting and material testing with a reasonable amount of time and personnel. The logistics of such studies present a hurdle for reproducibility. A structured procedure was developed and proved, which allows all necessary steps to be carried out reproducibly and in a reasonable time. This enables the extraction of 26 soft tissue, 33 trabecular and 32 cortical bone specimens from this anatomical region per cadaver. The integrity of the specimens remains maintained while keeping requirements within manageable limits. The practicability of the intended five-day specimen harvesting and testing procedure could be demonstrated on five test and two pre-test sequences. The intended minimization of physical, biological, and chemical external influences on specimens could be achieved. All protocols, instructions and models of preparation and storage devices are included in the supporting information. The high grade of applicability and reproducibility will lead to better comparability between different biomechanical investigations. This procedure proven on the human pelvis is transferable to other anatomical regions.
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Affiliation(s)
- Sascha Kurz
- ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Marc Gebhardt
- Institute of Experimental Mechanics, Faculty of Civil Engineering, Leipzig University of Applied Sciences, Leipzig, Germany
- Institute of Anatomy, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Fanny Grundmann
- Clinic of Trauma, Orthopedic and Septic Surgery, Hospital St. Georg gGmbH, Leipzig, Germany
| | - Christoph-Eckhard Heyde
- ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Hanno Steinke
- Institute of Anatomy, Faculty of Medicine, Leipzig University, Leipzig, Germany
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García-Vilana S, Sánchez-Molina D, Velázquez-Ameijide J, Llumà J, Arregui-Dalmases C. Relation between mechanical and densimetric properties to fractal dimension in human rib cortical bone. Med Eng Phys 2023; 117:104004. [PMID: 37331757 DOI: 10.1016/j.medengphy.2023.104004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 05/25/2023] [Accepted: 06/01/2023] [Indexed: 06/20/2023]
Abstract
BACKGROUND Numerous prior studies hypothesized a power-law relationship (E∝ρα) between cortical bone Young's modulus (E) and density (ρ) with an exponent 2.3≤α≤3.0, that has not been previously justified in the literature on a theoretical level. Moreover, despite the fact microstructure have been extensively studied, the material correlate of Fractal Dimension (FD) as a descriptor of bone microstructure was not clear in previous studies. METHODS This study examined the effect of mineral content and density on the mechanical properties of a large number of human rib cortical bone samples. The mechanical properties were calculated using Digital Image Correlation and uniaxial tensile tests. CT scans were used to calculate the Fractal Dimension (FD) of each specimen. For each specimen, the mineral (fmin), organic (forg) and water (fwat) weight fractions were determined. In addition, density was measured after a drying-and-ashing process. Then, Regression Analysis was employed to investigate the relationship between anthropometric variables, weight fractions, density and FD, as well as its impact on the mechanical properties. FINDINGS Young's modulus exhibited a power-law relationship with an exponent of α>2.3 when using the conventional density (wet density), but α=2 when using dry density (desecated specimens). In addition, FD increases with decreasing cortical bone density. A significant relationship has been found between FD and density, whereby FD is correlated with the embedding of low density regions in cortical bone. INTERPRETATION This study provides a new insight in the exponent value of the power-law relation between Young's Modulus and density, and relates bone behavior with the fragile fracture theory in ceramic materials. Moreover, the results suggest that Fractal Dimension is related to presence of low-density regions.
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Affiliation(s)
| | | | | | - J Llumà
- UPC-EEBE, Eduard Maristany, 14, 08019 Barcelona, Spain
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14
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Dóczi MO, Sződy R, Zwierczyk PT. Equivalent loads from the life-cycle of acetabular cages in relation to bone-graft transformation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 236:107564. [PMID: 37116425 DOI: 10.1016/j.cmpb.2023.107564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 04/06/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023]
Abstract
BACKGROUND AND OBJECTIVES Bone grafts placed behind acetabular cages change their structure in response to mechanical stimuli. The full consideration of lifestyle loads is extremely resource-intensive, so a method using substitutive loads was proposed to reduce the calculation cost. The aim of the study is to present and prove this method. METHODS By means of mechanical equations and using the force vectors from the literature which have the same initial point and their relative frequency, while applying a linear model, the average strain energy density distribution for all load cases can be calculated, compiling a matrix from the external loads. From the elements of this matrix, three substitutive load vectors can be calculated, which can be proven to produce the same strain energy density distribution by averaging their effects. The feasibility of using this to model the transformation of bone grafts placed behind acetabular cages is demonstrated with a finite element model, along with a reference calculation. RESULTS The substitutive load vectors could be calculated in closed form and the simulations showed that they produced a similar density distribution to the reference model with a numerical calculation error range. Accordingly, the density distribution calculated from bone graft transformation is almost the same. CONCLUSIONS In addition to the aforementioned linearity and the same initial point limitations, the applied method is able to produce the substitutive load vectors with which the calculation of the strain energy density distribution and the bone graft's new density distributions can be carried out faster.
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Affiliation(s)
- Martin O Dóczi
- Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., Budapest H-1111, Hungary.
| | - Róbert Sződy
- Dr. Manninger Jenő Trauma Center, Fiumei út 17, Budapest H-1081, Hungary
| | - Péter T Zwierczyk
- Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., Budapest H-1111, Hungary
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15
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Ge C, Chen Z, Cao P. Efficacy of percutaneous kyphoplasty on vertebral compression fractures with different bone mineral densities: a retrospective study. BMC Musculoskelet Disord 2023; 24:276. [PMID: 37038169 PMCID: PMC10088266 DOI: 10.1186/s12891-023-06341-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/20/2023] [Indexed: 04/12/2023] Open
Abstract
BACKGROUND This study was performed to investigate the clinical efficacy of percutaneous kyphoplasty (PKP) for vertebral compression fractures with different bone mineral densities (BMD). METHODS We performed a retrospective analysis of 232 patients with single-segment vertebral compression fractures who underwent PKP. Patients were divided into the normal BMD, osteopenia, and osteoporosis groups according to their average lumbar BMD before surgery. The visual analog scale (VAS) was used to compare differences in pain relief before and after surgery in each group. Corrections of the wedge angle and kyphotic angle before and after surgery were observed using anteroposterior and lateral radiographs and compared among the groups, as was the incidence of bone cement leakage. RESULTS Patients were followed up for 6-12 months, with an average follow-up time of 9.12 ± 1.68 months. The VAS score, wedge angle, and kyphotic angle of the three groups of patients decreased significantly at the end of the follow-up (P < 0.05). The changes in VAS score and wedge angle correction in the osteoporosis group were significantly larger than those in the normal BMD and osteopenia groups (P < 0.05). There were no significant differences among the three groups in terms of kyphotic angle correction or bone cement leakage rates (P > 0.05). CONCLUSIONS PKP has a positive effect on vertebral compression fractures with different BMD, and is especially suitable for osteoporotic vertebral compression fractures.
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Affiliation(s)
- Chen Ge
- Department of Orthopedics, Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 999, Xiwang road, Jiading district, Shanghai, 201801, China.
| | - Zhe Chen
- Department of Orthopedics, Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 999, Xiwang road, Jiading district, Shanghai, 201801, China
| | - Peng Cao
- Department of Orthopedics, Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 999, Xiwang road, Jiading district, Shanghai, 201801, China
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16
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Żochowski P, Cegła M, Berent J, Grygoruk R, Szlązak K, Smędra A. Experimental and numerical study on failure mechanisms of bone simulants subjected to projectile impact. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3687. [PMID: 36690586 DOI: 10.1002/cnm.3687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/22/2022] [Accepted: 01/14/2023] [Indexed: 05/12/2023]
Abstract
Analyses of the human bones failure mechanisms under projectile impact conditions can be made through performing of a large number of ballistic trials. But the amount of data that can be collected during ballistic experiments is limited due to the high dynamics of the process and its destructive character. Numerical analyses may support experimental methodologies allowing to better understand the principles of the phenomenon. Therefore, the main aim of the study was to create and to verify a numerical model of commercially available synthetic bone material-Synbone®. The model could be used in the future as a supporting tool facilitating forensic studies or designing processes of personal protection systems (helmets, bulletproof vests, etc.). Although Synbone® is commonly used in the ballistic experiments, the literature lacks reliable numerical models of this material. In order to define a numerical model of Synbone®, mechanical experiments characterizing the response of the material to the applied loads in a wide range of strains and strain rates were carried out. Based on the mechanical tests results, an appropriate material model was selected for the Synbone® composite and the values of constants in its equations were determined. Material characterization experiments were subsequently reproduced with numerical simulations and a high correlation of the results was obtained. The final validation of the material model was based on the comparison of the ballistic impact experiments and simulation results. High similarity obtained (relative error lower than 10%) demonstrates that the numerical model of Synbone® material was properly defined.
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Affiliation(s)
| | - Marcin Cegła
- Military Institute of Armament Technology, Zielonka, Poland
| | - Jarosław Berent
- Department of Forensic Medicine, Medical University of Lodz, Łódź, Poland
- Department of Criminal Proceedings and Forensics, Faculty of Law and Administration at the University of Łódź, Łódź, Poland
| | - Roman Grygoruk
- Institute of Mechanics and Printing, Faculty of Mechanical and Industrial Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Karol Szlązak
- Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Anna Smędra
- Department of Forensic Medicine, Medical University of Lodz, Łódź, Poland
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17
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Zaia A, Maponi P, Sallei M, Galeazzi R, Scendoni P. Measuring Drug Therapy Effect on Osteoporotic Fracture Risk by Trabecular Bone Lacunarity: The LOTO Study. Biomedicines 2023; 11:biomedicines11030781. [PMID: 36979760 PMCID: PMC10044723 DOI: 10.3390/biomedicines11030781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
An MRI method providing one parameter (TBLβ: trabecular-bone-lacunarity-parameter-β) that is sensitive to trabecular bone architecture (TBA) changes with aging and osteoporosis is under study as a new tool in the early diagnosis of bone fragility fracture. A cross-sectional and prospective observational study (LOTO: Lacunarity Of Trabecular bone in Osteoporosis) on over-50s women, at risk for bone fragility fracture, was designed to validate the method. From the baseline data, we observed that in women with prevalent vertebral fractures (VF+), TBA was differently characterized by TBLβ when osteoporosis treatment is considered. Here we verify the potential of TBLβ as an index of osteoporosis treatment efficacy. Untreated (N = 156) and treated (N = 123) women were considered to assess differences in TBLβ related to osteoporosis treatment. Prevalent VFs were found in 31% of subjects, 63% of which were under osteoporosis medications. The results show that TBLβ discriminates between VF+ and VF− patients (p = 0.004). This result is mostly stressed in untreated subjects. Treatment, drug therapy in particular (89% Bisphosphonates), significantly counteracts the difference between VF+ and VF− within and between groups: TBLβ values in treated patients are comparable to untreated VF− and statistically higher than untreated VF+ (p = 0.014) ones. These results highlight the potential role of TBLβ as an index of treatment efficacy.
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Affiliation(s)
- Annamaria Zaia
- Centre of Innovative Models and Technology for Ageing Care, Scientific Direction, IRCCS INRCA, 60121 Ancona, Italy
- Correspondence:
| | - Pierluigi Maponi
- School of Science and Technology, University of Camerino, 62032 Camerino, Italy
| | - Manuela Sallei
- Medical Imaging Division, Geriatric Hospital, IRCCS INRCA, 60121 Ancona, Italy
| | - Roberta Galeazzi
- Analysis Laboratory, Geriatric Hospital, IRCCS INRCA, 60121 Ancona, Italy
| | - Pietro Scendoni
- Rheumatology Division, Geriatric Hospital, IRCCS INRCA, 63900 Fermo, Italy
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18
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Mirzaei M, Jafari R, Allaveisi F, Jafari H, Alavi F. Fracture analysis of healthy and osteoporotic femora using clinical CT images, phantomless densitometry, and linear FE method. J Orthop Res 2023; 41:629-640. [PMID: 35730428 DOI: 10.1002/jor.25404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 02/04/2023]
Abstract
Computational fracture analysis has become a growing branch of orthopedic research. Particularly, the associated methods provide reliable tools for the analysis of 3D CT-based models of bone. This paper reports the results of such analyses for 15 human femora (healthy and osteoporotic) under different loading orientations (85 different analysis cases). A new method was developed for the calculation of the density distribution in the models from ordinary clinical CT images without calibration phantom. This method, along with a strain-energy-based linear finite element (FE) analysis scheme, was used to predict the fracture strength and pattern of 10 cadaveric femora, for which the mechanical testing results and calibrated FE models were already available. The very good agreement and consistency between different sets of results showed the reliability and accuracy of the new density calibration method, as well as the linear analysis scheme. Accordingly, the method was applied to five new clinical images, gathered from two clinics that used different scanners with different protocols. The strength and fracture pattern of each one of these specimens were analyzed under 15 different loading conditions. A consistent behavior was found for variation of the fracture load and pattern of all specimens with the loading orientations, while very clear contrasts were observed between the strength amplitudes of healthy and osteoporotic specimens. The proposed methods can be easily applied to ordinary daily (even archived) clinical CT scans to conduct fast and reliable fracture analysis of human femora for general bone research and opportunistic studies of osteoporosis and trauma.
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Affiliation(s)
- Majid Mirzaei
- Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Reyhaneh Jafari
- Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Farzaneh Allaveisi
- Department of Medical Physics, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Hamed Jafari
- Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Fatemeh Alavi
- Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
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19
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Biomechanical and clinical studies on lumbar spine fusion surgery: a review. Med Biol Eng Comput 2023; 61:617-634. [PMID: 36598676 DOI: 10.1007/s11517-022-02750-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 12/22/2022] [Indexed: 01/05/2023]
Abstract
Low back pain is associated with degenerative disc diseases of the spine. Surgical treatment includes fusion and non-fusion types. The gold standard is fusion surgery, wherein the affected vertebral segment is fused. The common complication of fusion surgery is adjacent segment degeneration (ASD). The ASD often leads to revision surgery, calling for a further fusion of adjacent segments. The existing designs of nonfusion type implants are associated with clinical problems such as subsidence, difficulty in implantation, and the requirement of revision surgeries. Various surgical approaches have been adopted by the surgeons to insert the spinal implants into the affected segment. Over the years, extensive biomechanical investigations have been reported on various surgical approaches and prostheses to predict the outcomes of lumbar spine implantations. Computer models have been proven to be very effective in identifying the best prosthesis and surgical procedure. The objective of the study was to review the literature on biomechanical studies for the treatment of lumbar spinal degenerative diseases. A critical review of the clinical and biomechanical studies on fusion spine surgeries was undertaken. The important modeling parameters, challenges, and limitations of the current studies were identified, showing the future research directions.
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20
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Carlsson J, Braesch-Andersen A, Ferguson SJ, Isaksson P. Fracture in porous bone analysed with a numerical phase-field dynamical model. J Mech Behav Biomed Mater 2023; 139:105659. [PMID: 36638634 DOI: 10.1016/j.jmbbm.2023.105659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/13/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
A dynamic phase-field fracture finite element model is applied to discretized high-resolution three-dimensional computed tomography images of human trabecular bone to analyse rapid bone fracture. The model is contrasted to quasi-static experimental results and a quasi-static phase-field finite element model. The experiment revealed complex stepwise crack evolution with multiple crack fronts, and crack arrests, as the global tensile displacement load was incrementally increased. The quasi-static phase-field fracture model captures the fractures in the experiment reasonably well, and the dynamic model converges towards the quasi-static model when mechanically loaded at low rates. At higher load rates, i.e., at larger impulses, inertia effects significantly contribute to an increased initial global stiffness, higher peak forces and a larger number of cracks spread over a larger volume. Since the fracture process clearly is different at large impulses compared to small impulses, it is concluded that dynamic fracture models are necessary when simulating rapid bone fracture.
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Affiliation(s)
- Jenny Carlsson
- Solid Mechanics, Department of Materials Science and Engineering, Uppsala University, Sweden; Now at Cambridge University Engineering Department, Trumpington St., Cambridge, UK
| | - Anna Braesch-Andersen
- Solid Mechanics, Department of Materials Science and Engineering, Uppsala University, Sweden
| | | | - Per Isaksson
- Solid Mechanics, Department of Materials Science and Engineering, Uppsala University, Sweden.
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21
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Rothenfluh E, Jain S, Guggenberger R, Taylor WR, Hosseini Nasab SH. The influence of partial union on the mechanical strength of scaphoid fractures: a finite element study. J Hand Surg Eur Vol 2023; 48:435-444. [PMID: 36814409 PMCID: PMC10150260 DOI: 10.1177/17531934231157565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Assessment of scaphoid fracture union on computed tomography scans is not currently standardized. We investigated the extent of scaphoid waist fracture union required to withstand physiological loads in a finite element model, based on a high-resolution CT scan of a cadaveric forearm. For simulations, the scaphoid waist was partially fused at the radial and ulnar sides. A physiological load of 100 N was transmitted to the scaphoid and the minimal amount of union to maintain biomechanical stability was recorded. The orientation of the fracture plane was varied to analyse the effect on biomechanical stability. The results indicate that the scaphoid is more prone to re-fracture when healing occurs on the ulnar side, where at least 60% union is required. Union occurring from the radial side can withstand loads with as little as 25% union. In fractures more parallel to the radial axis, the scaphoid seems less resistant on the radial side, as at least 50% union is required. A quantitative CT scan analysis with the proposed cut-off values and a consistently applied clinical examination will guide the clinician as to whether mid-waist scaphoid fractures can be considered as truly united.
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Affiliation(s)
- Esin Rothenfluh
- Department of Plastic and Hand
Surgery, University Hospital Zurich, Zurich, Switzerland
- Esin Rothenfluh, Department of Plastic and
Hand Surgery, University Hospital of Bern (Inselspital), Freiburgstrasse 18,
3010 Bern, Switzerland.
| | - Sambhav Jain
- Department of Plastic and Hand
Surgery, University Hospital Zurich, Zurich, Switzerland
- Laboratory for Movement
Biomechanics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich,
Switzerland
| | - Roman Guggenberger
- Institute of Diagnostic and
Interventional Radiology, University Hospital Zurich, Zurich, Switzerland
| | - William R. Taylor
- Laboratory for Movement
Biomechanics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich,
Switzerland
| | - Seyyed Hamed Hosseini Nasab
- Laboratory for Movement
Biomechanics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich,
Switzerland
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22
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Lin J, Fan Y, Hutchinson DJ, Malkoch M. Soft Hydroxyapatite Composites Based on Triazine-Trione Systems as Potential Biomedical Engineering Frameworks. ACS APPLIED MATERIALS & INTERFACES 2023; 15:7329-7339. [PMID: 36695708 PMCID: PMC9923673 DOI: 10.1021/acsami.2c16235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
Composites of triazine-trione (TATO) thiol-ene networks and hydroxyapatite (HA) have shown great potential as topological fixation materials for complex bone fractures due to their high flexural modulus, biocompatibility, and insusceptibility to forming soft-tissue adhesions. However, the rigid mechanical properties of these composites make them unsuitable for applications requiring softness. The scope of these materials could therefore be widened by the design of new TATO monomers that would lead to composites with a range of mechanical properties. In this work, four novel TATO-based monomers, decorated with either ester or amide linkages as well as alkene or alkyne end groups, have been proposed and synthesized via fluoride-promoted esterification (FPE) chemistry. The ester-modified monomers were then successfully formulated along with the thiol TATO monomer tris [2-(3-mercaptopropionyloxy)ethyl] isocyanurate (TEMPIC) and HA to give soft composites, following the established photo-initiated thiol-ene coupling (TEC) or thiol-yne coupling (TYC) chemistry methodologies. The most promising composite shows excellent softness, with a flexural modulus of 57 (2) MPa and εf at maximum σf of 11.8 (0.3)%, which are 117 and 10 times softer than the previously developed system containing the commercially available tri-allyl TATO monomer (TATATO). Meanwhile, the surgically convenient viscosity of the composite resins and their excellent cytotoxicity profile allow them to be used in the construction of soft objects in a variety of shapes through drop-casting suitable for biomedical applications.
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23
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Gaujac N, Sariali E, Grimal Q. Does the bone mineral density measured on a preoperative CT scan before total hip arthroplasty reflect the bone's mechanical properties? Orthop Traumatol Surg Res 2023; 109:103348. [PMID: 35688378 DOI: 10.1016/j.otsr.2022.103348] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 02/07/2023]
Abstract
INTRODUCTION No method exists to quantify the bone quality and factors that will ensure osteointegration of total hip arthroplasty (THA) implants. A preoperative CT scan can be used to evaluate the bone mineral density (BMD) when planning a THA procedure. The aim of this study was to validate BMD measurement as a marker of bone quality based on a preoperative CT scan. HYPOTHESIS BMD reflects the bone's mechanical properties for the purposes of preoperative THA planning. METHODS Patients who underwent primary THA for hip osteoarthritis or dysplasia with cementless implants and 3D preoperative plan were enrolled prospectively. The cortical BMD was calculated on CT scans used in the preoperative planning process. During the surgical procedure, the femoral head and neck were collected. These bone samples were subsequently scanned with a calibrated micro-CT scanner. The BMD was derived from the micro-CT scan and used as input for a finite element model to determine the bone's mechanical properties. Correlations between BMD, apparent moduli of elasticity and porosity were calculated. RESULTS The values of cortical BMD measured on the micro-CT and CT scan were significantly correlated (cc=0.52). The mean angular cortical BMD measured with the micro-CT scan was 1472.33mg/cm3 (SD: 357.53mg/cm3, 980.64-2830.6mg/cm3). There was no significant correlation between cortical BMD and the various apparent moduli of elasticity, except for Eyy and Gzy. Cortical BMD and porosity were inversely correlated with a Spearman coefficient of -0.41 (CI95: [-0.71; -0.02], p=0.03). There was also an inverse correlation between the apparent moduli of elasticity (independent of their orientation) and porosity (p<0.01). DISCUSSION BMD provides information about porosity, which is a major factor when evaluating the bone's mechanical properties before THA. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Nicolas Gaujac
- Department of Orthopaedic Surgery, Hôpital La Pitié Salpétrière, 47-83, boulevard de l'Hôpital, 75013 Paris, France
| | - Elhadi Sariali
- Department of Orthopaedic Surgery, Hôpital La Pitié Salpétrière, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
| | - Quentin Grimal
- Sorbonne Université, INSERM, CNRS, Laboratoire d'Imagerie Biomédicale, LIB, 15, rue de l'Ecole de Médecine, 75006 Paris, France
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Soukup JW, Jeffery J, Drizin SR, Hetzel SJ, Stone DS, Eriten M, Ploeg HL, Henak CR. Correlation of mineral density and elastic modulus of dog dentin using μ-CT and nanoindentation. J Biomech 2023; 147:111434. [PMID: 36638579 PMCID: PMC9893440 DOI: 10.1016/j.jbiomech.2023.111434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/02/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023]
Abstract
This study sought to 1) investigate the spatial distribution of mineral density of dog dentin using µ-CT and 2) characterize the relationship between the elastic modulus and mineral density of dog dentin using nanoindentation and µ-CT. Maxillary canine teeth of 10 mature dogs were scanned with a µ-CT then sectioned in the transverse and vertical planes and tested using nanoindentation. Spatial distribution of mineral density and elastic modulus was quantified. Results demonstrated significant spatial variation in mineral density and elastic modulus. Mineral density and elastic modulus generally increased from the dentin-pulp interface to the dentino-enamel junction and from the crown base to the crown tip. Significant site dependent correlations between mineral density and elastic modulus were determined (0.021 > R2 > 0.408). The results of this study suggest that while mineral density is a mediator of elastic modulus, other mediators such as collagen content may contribute to the mechanical behavior of dog dentin.
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Affiliation(s)
- Jason W Soukup
- Department of Surgical Sciences, University of Wisconsin-Madison, School of Veterinary Medicine, Madison, WI, USA.
| | - Justin Jeffery
- Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Sienna R Drizin
- Department of Surgical Sciences, University of Wisconsin-Madison, School of Veterinary Medicine, Madison, WI, USA
| | - Scott J Hetzel
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Donald S Stone
- Department of Materials Science and Engineering, University of Wisconsin-Madison, College of Engineering, Madison, WI, USA
| | - Melih Eriten
- Department of Mechanical Engineering, University of Wisconsin-Madison, College of Engineering, Madison, WI, USA
| | - Heidi-Lynn Ploeg
- Department of Mechanical Engineering, University of Wisconsin-Madison, College of Engineering, Madison, WI, USA; Department of Mechanics and Materials Engineering, Queen's University, Kingston, ON, Canada
| | - Corinne R Henak
- Department of Mechanical Engineering, University of Wisconsin-Madison, College of Engineering, Madison, WI, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
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25
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Agnelli J, Colombo M, Morroni M, Bignotti F, Baldi F. Mechanical behaviour of cancellous bone tissues used for the manufacturing of heterologous bone grafts. BIOMEDICAL ENGINEERING ADVANCES 2023. [DOI: 10.1016/j.bea.2023.100073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Metzner F, Fischer B, Heyde CE, Schleifenbaum S. The effects of force application on the compressive properties of femoral spongious bone. Clin Biomech (Bristol, Avon) 2023; 101:105866. [PMID: 36577361 DOI: 10.1016/j.clinbiomech.2022.105866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND End artefacts play a major role in uniaxial compression tests with cancellous bone specimens. They lead to misinterpretation of mechanical parameters of bones due to uncontrolled introduction of bending moments into the free ends of trabeculae. This work aims to simplify current methods preventing end-artefacts and furthermore to investigate the influence of end artefacts on plateau stress. METHODS 176 cylindrical cancellous bone specimens were taken from human femoral condyles and tested in uniaxial compression. The specimens were divided into 2 groups (direct, end-cap) and compressive modulus, maximum stress, plateau stress, energy absorbtion as well as apparent density were evaluated. Density values are from separate specimens which are immediately adjacent to the mechanical specimen. FINDINGS All mechanical parameters were significantly higher in the end-cap specimens than in the direct ones by about 30 - 40 %, thus reaching similar differences as the previous studies. Greatest differences between groups were determined for compressive modulus (45 %) and plateau stress (35 %). Energy absorbtion can be explained with great accuracy by plateau stress (P < 0.001; R2 = 0.95). Among all parameters plateau stress can be best explained by apparent density using an exponential function (P < 0.001; R2 = 0.38). INTERPRETATION The end-cap method used here to prevent end artefacts showed variations consistent with the literature when compared to the direct method. Additionally it was shown that the way in which the force is applied to the specimen has a major influence on the failure progression behavior, which was characterized using the plateau stress.
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Affiliation(s)
- F Metzner
- ZESBO - Centre for Research on Musculoskeletal Systems, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany.
| | - B Fischer
- ZESBO - Centre for Research on Musculoskeletal Systems, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany
| | - C-E Heyde
- ZESBO - Centre for Research on Musculoskeletal Systems, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany
| | - S Schleifenbaum
- ZESBO - Centre for Research on Musculoskeletal Systems, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University of Leipzig, Leipzig, Germany; Fraunhofer Institute for Machine Tools and Forming Technology, Dresden, Germany
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27
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Behforootan S, Thorniley M, Minonzio JG, Boughton O, Karia M, Bhattacharya R, Hansen U, Cobb J, Abel R. Can guided wave ultrasound predict bone mechanical properties at the femoral neck in patients undergoing hip arthroplasty? J Mech Behav Biomed Mater 2022; 136:105468. [PMID: 36244325 DOI: 10.1016/j.jmbbm.2022.105468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/30/2022] [Accepted: 09/16/2022] [Indexed: 11/06/2022]
Abstract
The bone quality of patients undergoing hip replacement surgery is poorly predicted by radiographs alone. With better bone quality information available to a surgeon, the operation can be performed more safely. The aim of this study was to investigate whether ultrasound signals of cortical bone at peripheral sites such as the tibia and radius can be used to predict the compressive mechanical properties of cortical bone at the femoral neck. We recruited 19 patients undergoing elective hip arthroplasty and assessed the radius and tibia of these patients with the Azalée guided wave ultrasound to estimate the porosity and thickness of the cortex. Excess bone tissues were collected from the femoral neck and the compressive mechanical properties of the cortex were characterised under a mechanical loading rig to determine stiffness, ultimate strength, and density. The correlations between the ultrasound measurements and mechanical properties were analysed using linear regression, Pearson correlation statistics, and multiple regression analysis. Cortical mechanical properties were weakly to moderately correlated with the ultrasound measurements at various sites (R2 = 0.00-0.36). The significant correlations found were not consistent across all 4 peripheral measurement sites. Additionally, weak to moderate ability of the ultrasound to predict mechanical properties at the neck of femur with multiple regression analysis was found (R2 = 0.00-0.48). Again, this was inconsistent across the different anatomical sites. Overall, the results demonstrate the need for ultrasound scans to be collected directly from clinically relevant sites such as the femoral neck due to the inconsistency of mechanical properties across various sites.
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Affiliation(s)
- Sara Behforootan
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK.
| | - Madelaine Thorniley
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK
| | - Jean-Gabriel Minonzio
- Escuela de Ingeniería Informática, Centro de Investigación y Desarrollo en Ingeniería en Salud, Universidad de Valparaíso, Valparaíso, Chile & Sorbonne Université, INSERM UMR S 1146, CNRS UMR 7371, Laboratoire d'Imagerie Biomédicale, Paris, France
| | - Oliver Boughton
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK
| | - Monil Karia
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK
| | | | - Ulrich Hansen
- Department of Mechanical Engineering, Faculty of Engineering, Imperial College London, UK
| | - Justin Cobb
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK
| | - Richard Abel
- MSK Lab, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK
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28
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Chen D, Li D, Pan K, Gao S, Wang B, Sun M, Zhao C, Liu X, Li N. Strength enhancement and modulus modulation in auxetic meta-biomaterials produced by selective laser melting. Acta Biomater 2022; 153:596-613. [PMID: 36162764 DOI: 10.1016/j.actbio.2022.09.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/25/2022] [Accepted: 09/18/2022] [Indexed: 11/01/2022]
Abstract
Meta-biomaterials are applied to orthopedic implants to avoid stress shielding effects; however, there is no reason for the yield strength to be comparable to that of human bone. In this study, a composite unit cell was designed by combining the positive Poisson's ratio (PPR) and negative Poisson's ratio (NPR) unit cells, inspired by the second-phase strengthening theory. The purpose was to increase the strength while maintaining the elastic modulus. All structures were successfully fabricated from Ti-6Al-4V via selective laser melting. The relative density is between 0.08 and 0.24, which falls within the optimal range for bone growth. Mechanical tests indicated that the center of the inclined rod fractured in a stepwise fracture mode, which was consistent with the predictions of the Johnson-Cook model. The elastic modulus ranged from 0.652 ± 0.016 to 5.172 ± 0.021 GPa, and the yield strength varied from 10.62 ± 0.112 to 87.158 ± 2.215 MPa. An improved Gibson-Ashby law was proposed to facilitate the design of gradient structures. When the re-entrant angle was 40°, a hybrid body-centered cubic NPR structure was formed, resulting in a significant improvement in the mechanical properties. Importantly, the yield strength of the proposed composite structures increased by 43.23%, and the compression strength increased by 44.70% under the same elastic modulus. The strengthening mechanism has been proven to apply to other bending-dominated structures. Overall, this imparts unprecedented mechanical performance to auxetic meta-biomaterials and provides insights into improving the reported porous structures. STATEMENT OF SIGNIFICANCE: : Auxetic meta-biomaterials exhibit auxetic properties that can improve the contact between the bone-implant interface and reduce the risk of aseptic failure. To avoid the stress shielding effect, the elastic modulus has traditionally been decreased by increasing the porosity. However, the strength is simultaneously reduced. Therefore, a composite unit cell was proposed to increase strength rather than modulus by combining the positive and negative Poisson's ratio unit cells, inspired by the second-phase strengthening theory. We observed a 43.23% increase in the yield strength of the composite structure without increasing the elastic modulus. This strengthening mechanism has been proven to apply to other bending-dominated structures. Our approach provides insights into improving other bending-dominated structures and broadening their applications for bone implantation.
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Affiliation(s)
- Dongxu Chen
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dongdong Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Kejia Pan
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shuai Gao
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bao Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Minghan Sun
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Chao Zhao
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaotao Liu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ning Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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Pham TT, Le LH, Khodaei M, Zheng R, Lou E. Investigation of ultrasonic soft tissue-bone reflection coefficients correlating with curve severity in children with adolescent idiopathic scoliosis. Proc Inst Mech Eng H 2022; 236:1403-1413. [PMID: 35880904 PMCID: PMC9449449 DOI: 10.1177/09544119221114200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) is a three-dimensional curvature of spine.
Children with AIS and low bone quality have higher chance to get curve
progression leading to bigger spinal curvature. In addition, bone quality
affects acoustic impedance of bone, thus influencing the reflection coefficient
of ultrasound signal from the soft tissue–bone interface. This study aimed to
estimate the bone quality of AIS patients based on the reflection coefficients
to determine the correlation of the bone quality with curve severity. A simple
bone model was used to develop an equation to calculate the reflection
coefficient value. Experiments were conducted on five different phantoms.
Acrylic was used to design a vertebral shape to study the effect of surface
roughness and inclination, including: smooth flat surface (SFS), smooth curved
surface (SCS), rough curved surface (RCS), and the rough curved inclined surface
(RCIS). A clinical study with 37 AIS patients were recruited. The estimated
reflection coefficient values of plate phantoms agreed well with the predicted
values and the maximum error was 6.7%. The reflection coefficients measured from
the acrylic-water interface for the SFS, SCS, RCS, RCIS (3° and 5°) were 0.37,
0.33, 0.28, (0.23 and 0.12), respectively. The surface roughness and inclination
increased the reflection loss. From the clinical data, the average reflection
coefficients for children with AIS were 0.11 and 0.07 for the mild curve group
and the moderate curve group, respectively. A moderate linear correlation was
found between the reflection coefficients and curve severity (r2 = 0.3). Patients with lower bone quality have observed to have
larger spinal curvature.
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Affiliation(s)
- Thanh-Tu Pham
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Lawrence H Le
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Mahdieh Khodaei
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
| | - Rui Zheng
- School of Information Science and Technology, ShanghaiTech University, Shanghai, China
| | - Edmond Lou
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, Canada
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30
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Laurent C, Marano A, Baldit A, Ferrari M, Perrin JC, Perroud O, Bianchi A, Kempf H. A preliminary study exploring the mechanical properties of normal and Mgp-deficient mouse femurs during early growth. Proc Inst Mech Eng H 2022; 236:1106-1117. [PMID: 35778813 DOI: 10.1177/09544119221109019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Matrix Gla protein (MGP) is mostly known to be a calcification inhibitor, as its absence leads to ectopic calcification of different tissues such as cartilage or arteries. MGP deficiency also leads to low bone mass and delayed bone growth. In the present contribution, we investigate the effect of MGP deficiency on the structural and material mechanical bone properties by focusing on the elastic response of femurs undergoing three-points bending. To this aim, biomechanical tests are performed on femurs issued from Mgp-deficient mice at 14, 21, 28, and 35 days of postnatal life and compared to healthy control femurs. µCT acquisitions enable to reconstruct bone geometries and are used to construct subject-specific finite element models avoiding some of the reported limitations concerning the use of beam-like assumptions for small bone samples. Our results indicate that MGP deficiency may be associated to differences in both structural and material properties of femurs during early stages of development. MGP deficiency appears to be related to a decrease in bone dimensions, compensated by higher material properties resulting in similar structural bone properties at P35. The search for a unique density-elasticity relationship based on calibrated bone mineral density (BMD) indicates that MGP deficiency may affect bone tissue in several ways, that may not be represented uniquely from the quantification of BMD. Despite of its limitation to elastic response, the present preliminary study reports for the very first time the mechanical skeletal properties of Mgp-deficient mice at early stages of development.
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Affiliation(s)
- Cédric Laurent
- CNRS UMR 7239 LEM3, Université de Lorraine, Metz, France
| | - Alexandre Marano
- CNRS UMR 7365 IMoPA, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Adrien Baldit
- CNRS UMR 7239 LEM3, Université de Lorraine, Metz, France
| | - Maude Ferrari
- CNRS UMR 7563 LEMTA, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | | | | | - Arnaud Bianchi
- CNRS UMR 7365 IMoPA, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Hervé Kempf
- CNRS UMR 7365 IMoPA, Université de Lorraine, Vandœuvre-lès-Nancy, France
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31
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Garay RS, Solitro GF, Lam KC, Morris RP, Albarghouthi A, Lindsey RW, Latta LL, Travascio F. Characterization of regional variation of bone mineral density in the geriatric human cervical spine by quantitative computed tomography. PLoS One 2022; 17:e0271187. [PMID: 35802639 PMCID: PMC9269429 DOI: 10.1371/journal.pone.0271187] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/24/2022] [Indexed: 11/23/2022] Open
Abstract
Background Odontoid process fractures are among the most common in elderly cervical spines. Their treatment often requires fixation, which may include use of implants anteriorly or posteriorly. Bone density can significantly affect the outcomes of these procedures. Currently, little is known about bone mineral density (BMD) distributions within cervical spine in elderly. This study documented BMD distribution across various anatomical regions of elderly cervical vertebrae. Methods and findings Twenty-three human cadaveric C1-C5 spine segments (14 males and 9 female, 74±9.3 y.o.) were imaged via quantitative CT-scan. Using an established experimental protocol, the three-dimensional shapes of the vertebrae were reconstructed from CT images and partitioned in bone regions (4 regions for C1, 14 regions for C2 and 12 regions for C3-5). The BMD was calculated from the Hounsfield units via calibration phantom. For each vertebral level, effects of gender and anatomical bone region on BMD distribution were investigated via pertinent statistical tools. Data trends suggested that BMD was higher in female vertebrae when compared to male ones. In C1, the highest BMD was found in the posterior portion of the bone. In C2, BMD at the dens was the highest, followed by lamina and spinous process, and the posterior aspect of the vertebral body. In C3-5, lateral masses, lamina, and spinous processes were characterized by the largest values of BMD, followed by the posterior vertebral body. Conclusions The higher BMD values characterizing the posterior aspects of vertebrae suggest that, in the elderly, posterior surgical approaches may offer a better fixation quality.
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Affiliation(s)
- Ryan S. Garay
- Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, Florida, United States of America
| | - Giovanni F. Solitro
- Louisiana State University Health-Shreveport, Shreveport, Louisiana, United States of America
| | - Kenrick C. Lam
- University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Randal P. Morris
- University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Abeer Albarghouthi
- Max Biedermann Institute for Biomechanics, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
| | - Ronald W. Lindsey
- University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Loren L. Latta
- Max Biedermann Institute for Biomechanics, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
- Department of Orthopaedic Surgery, University of Miami, Miami, Florida, United States of America
| | - Francesco Travascio
- Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, Florida, United States of America
- Max Biedermann Institute for Biomechanics, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
- Department of Orthopaedic Surgery, University of Miami, Miami, Florida, United States of America
- Department of Industrial Engineering, University of Miami, Coral Gables, Florida, United States of America
- * E-mail:
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32
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Numerical Analysis of the Calcaneal Nail C-NAIL. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12105265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The presented article investigates the biomechanics of the calcaneal nail C-NAILTM by numerical calculations and, partially, experimentally. This nail is widely used in trauma and orthopaedics. A numerical model of implants directly interacting with the bone tissue model obtained from CT scans was calculated. The material properties of the bone tissue can be described by several models; in this work, a non-homogeneous material model with isotropic elements and prescribed elastic modulus was used to provide a more accurate model of the applied force distribution on the individual parts of the implants. The critical areas of the nail and its fixtures were investigated using finite element strength calculations to verify their strength and reliability, contributing to the safety and faster and easier treatment of patients. These analyses suggest that the strength of the calcaneal nail C-NAIL, as well as the stabilization of bone fragments resulting from its use, are sufficient for clinical practice.
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33
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Pramudita JA, Hiroki W, Yoda T, Tanabe Y. Variations in Strain Distribution at Distal Radius under Different Loading Conditions. Life (Basel) 2022; 12:life12050740. [PMID: 35629407 PMCID: PMC9144860 DOI: 10.3390/life12050740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 11/16/2022] Open
Abstract
Distal radial fractures exhibit various fracture patterns. By assuming that the strain distribution at the distal radius affects the diversification of the fracture pattern, a parameter study using the finite element model of a wrist developed from computed tomography (CT) images was performed under different loading conditions. The finite element model of the wrist consisted of the radius, ulna, scaphoid, lunate, triquetrum, and major carpal ligaments. The material properties of the bone models were assigned on the basis of the Hounsfield Unit (HU) values of the CT images. An impact load was applied to the scaphoid, lunate, and triquetrum to simulate boundary conditions during fall accidents. This study considered nine different loading conditions that combine three different loading directions and three different load distribution ratios. According to the analysis results, the strain distribution at the distal radius changed with respect to the change in the loading condition. High strain concentration occurred in regions where distal radius fractures are commonly developed. The direction and distribution of the load acting on the radius were considered to be factors that may cause variations in the fracture pattern of distal radius fractures.
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Affiliation(s)
- Jonas A. Pramudita
- College of Engineering, Nihon University, Koriyama 963-8642, Japan
- Correspondence:
| | - Wataru Hiroki
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
| | - Takuya Yoda
- Graduate School of Medical and Dental Sciences, Niigata University, Niigata 950-2181, Japan;
| | - Yuji Tanabe
- Management Strategy Section, President Office, Niigata University, Niigata 950-2181, Japan;
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Youssefian S, Bressner JA, Osanov M, Guest JK, Zbijewski WB, Levin AS. Sensitivity of the stress field of the proximal femur predicted by CT-based FE analysis to modeling uncertainties. J Orthop Res 2022; 40:1163-1173. [PMID: 34191377 PMCID: PMC8716646 DOI: 10.1002/jor.25138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 04/25/2021] [Accepted: 06/25/2021] [Indexed: 02/04/2023]
Abstract
Proximal femur anatomy and bone mineral density vary widely among individuals, precluding the use of one predefined finite element (FE) model to determine the stress field for all proximal femurs. This variability poses a challenge in current prosthetic hip design approach. Given the numerous options for generating computed tomography (CT)-based FE models, selecting the best methods for defining the mechanical behavior of the proximal femur is difficult. In this study, a combination of computational and experimental approaches was used to explore the susceptibility of the predicted stress field of the proximal femur to different combinations of density-elasticity relationships, element type, element size, and calibration error. Our results suggest that FE models with first-order voxelized elements generated by the Keyak and Falkinstein density-elasticity relationship or quadratic tetrahedral elements generated by the Morgan density-elasticity relationship lead to accurate estimations of the mechanical behavior of human femurs. Other combinations of element size, element type, and mathematical relationships produce less accurate results, especially in the cortical bone of the femoral neck and calcar region. The voxelized model was more susceptible to variation of element size and density-elasticity relationships than FE models with quadratic tetrahedral elements. Regardless of element type, the stress fields predicted by the Keyak and Falkinstein and the Morgan relationships were the most robust to calibration error when deriving material density from CT-generated Hounsfield data. These results provide insight into the implementation of a robust platform for designing patient-specific implants capable of maintaining or modifying the stress in bones.
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Affiliation(s)
- Sina Youssefian
- Department of Civil and Systems Engineering The Johns Hopkins University Baltimore Maryland USA
| | - Jarred A. Bressner
- Department of Orthopaedic Surgery The Johns Hopkins University School of Medicine Baltimore Maryland USA
| | - Mikhail Osanov
- Department of Civil and Systems Engineering The Johns Hopkins University Baltimore Maryland USA
| | - James K. Guest
- Department of Civil and Systems Engineering The Johns Hopkins University Baltimore Maryland USA
| | - Wojciech B. Zbijewski
- Department of Biomedical Engineering The Johns Hopkins University Baltimore Maryland USA
| | - Adam S. Levin
- Department of Orthopaedic Surgery The Johns Hopkins University School of Medicine Baltimore Maryland USA
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35
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Sun X, Jiao X, Yang X, Ma J, Wang T, Jin W, Li W, Yang H, Mao Y, Gan Y, Zhou X, Li T, Li S, Chen X, Wang J. 3D bioprinting of osteon-mimetic scaffolds with hierarchical microchannels for vascularized bone tissue regeneration. Biofabrication 2022; 14. [PMID: 35417902 DOI: 10.1088/1758-5090/ac6700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 04/13/2022] [Indexed: 11/12/2022]
Abstract
The integration of three-dimensional (3D) bioprinted scaffold's structure and function for critical-size bone defect repair is of immense significance. Inspired by the basic component of innate cortical bone tissue--osteons, many studies focus on biomimetic strategy. However, the complexity of hierarchical microchannels in the osteon, the requirement of mechanical strength of bone, and the biological function of angiogenesis and osteogenesis remain challenges in the fabrication of osteon-mimetic scaffolds. Therefore, we successfully built mimetic scaffolds with vertically central medullary canals, peripheral Haversian canals, and transverse Volkmann canals structures simultaneously by 3D bioprinting technology using polycaprolactone and bioink loading with bone marrow mesenchymal stem cells (BMSCs) and bone morphogenetic protein-4 (BMP-4). Subsequently, endothelial progenitor cells (EPCs) were seeded into the canals to enhance angiogenesis. The porosity and compressive properties of bioprinted scaffolds could be well controlled by altering the structure and canal numbers of the scaffolds. The osteon-mimetic scaffolds showed satisfactory biocompatibility and promotion of angiogenesis and osteogenesis in vitro and prompted the new blood vessels and new bone formation in vivo. In summary, this study proposes a biomimetic strategy for fabricating structured and functionalized 3D bioprinted scaffolds for vascularized bone tissue regeneration.
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Affiliation(s)
- Xin Sun
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Xin Jiao
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Xue Yang
- College of Medicine, Southwest JiaoTong University, No. 111 2nd Ring Rd, Chengdu, 610031, CHINA
| | - Jie Ma
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Tianchang Wang
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Wenjie Jin
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Wentao Li
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Han Yang
- School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954 Huashan Road, Shanghai, 200030, CHINA
| | - Yuanqing Mao
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Yaokai Gan
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Xiaojun Zhou
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, No. 2999 North Renmin Road, Shanghai, 201620, CHINA
| | - Tao Li
- Xinhua Hospital Affiliated to Shanghai JiaoTong University School of Medicine, No.1665 Kongjiang Road, Shanghai, 200092, CHINA
| | - Shuai Li
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
| | - Xiaodong Chen
- Xinhua Hospital Affiliated to Shanghai JiaoTong University School of Medicine, No.1665 Kongjiang Road, Shanghai, 200092, CHINA
| | - Jinwu Wang
- Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, No.639 Zhizaoju Road, Shanghai, 200001, CHINA
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Ayyachi T, Pappalardo D, Finne‐Wistrand A. Defining the role of linoleic acid in acrylic bone cement. J Appl Polym Sci 2022. [DOI: 10.1002/app.52409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Thayanithi Ayyachi
- Department of Fibre and Polymer Technology School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology Stockholm Sweden
| | - Daniela Pappalardo
- Dipartimento di Scienze e Tecnologie Università del Sannio Benevento Italy
| | - Anna Finne‐Wistrand
- Department of Fibre and Polymer Technology School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology Stockholm Sweden
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Comparison of the biomechanical performance of three spinal implants for treating the wedge-shaped burst fractures. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2021.100109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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38
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Baines AJ, Babazadeh-Naseri A, Dunbar NJ, Lewis VO, Fregly BJ. Bilateral asymmetry of bone density adjacent to pelvic sarcomas: A retrospective study using computed tomography. J Orthop Res 2022; 40:644-653. [PMID: 33914952 DOI: 10.1002/jor.25067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/12/2021] [Accepted: 04/26/2021] [Indexed: 02/04/2023]
Abstract
Limb-salvaging hemipelvectomy surgeries involving allograft or custom prosthesis reconstruction require high quality remaining pelvic bone for adequate device fixation. Modeling studies of custom pelvis prosthesis designs typically mirror contralateral pelvic bone material properties to the ipsilateral pelvis. However, the extent of bone material property and geometric symmetry, and thus the appropriateness of mirroring, remains unknown and should be considered when designing or analyzing the performance of pelvic prostheses. This study investigates preoperative differences between ipsilateral and contralateral pelvic bone for patients with a pelvic sarcoma. Computed tomography (CT) data were obtained retrospectively from eight patients with a pelvic sarcoma. Subject-specific computational models of the pelvic bones were constructed from the CT data. Bilateral asymmetry of bone material properties and cross-sectional areas between the ipsilateral and contralateral hemipelvis were quantified at points adjacent to the pelvic sarcoma. Large bilateral asymmetry (>20%) in trabecular but not cortical bone density was observed within 20 mm of the tumor location. Differences in trabecular bone density typically declined with increased distance from the tumor. The greatest bilateral difference in cross-sectional area occurred within 10 mm of the tumor boundary for three patients and within 40 mm from the tumor site for four patients. Our results suggest that pelvic sarcomas can cause significant bilateral asymmetries in trabecular bone density for patients with a pelvic sarcoma. These differences should be taken into account when designing custom implants for this patient population.
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Affiliation(s)
- Andrew J Baines
- Department of Mechanical Engineering, Rice University, Houston, Texas, USA
| | | | - Nicholas J Dunbar
- Department of Mechanical Engineering, Rice University, Houston, Texas, USA
| | - Valerae O Lewis
- Department of Orthopaedic Oncology, MD Anderson Cancer Center, Houston, Texas, USA
| | - Benjamin J Fregly
- Department of Mechanical Engineering, Rice University, Houston, Texas, USA
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Soltanmohammadi P, Tavakoli A, Langohr GDG, Athwal GS, Willing R. Structural analysis of hollow versus solid-stemmed shoulder implants of proximal humeri with different bone qualities. J Orthop Res 2022; 40:674-684. [PMID: 33969537 DOI: 10.1002/jor.25076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/24/2021] [Accepted: 05/03/2021] [Indexed: 02/04/2023]
Abstract
Stress shielding of the proximal humerus following total shoulder arthroplasty (TSA) can promote unfavorable bone remodeling, especially for osteoporotic patients. The objective of this finite element (FE) study was to determine if a hollow, rather than solid, titanium stem can mitigate this effect for healthy, osteopenic, and osteoporotic bone. Using a population-based model of the humerus, representative average healthy, osteopenic, and osteoporotic humerus FE models were created. For each model, changes in bone and implant stresses following TSA were evaluated for different loading scenarios and compared between solid versus hollow-stemmed implants. For cortical bone, using an implant decreased von Mises stress with respect to intact values up to 34.4%, with a more pronounced effect at more proximal slices. In the most proximal slice, based on changes in strain energy density, hollow-stemmed implants outperformed solid-stemmed ones through reducing cortical bone volume with resorption potential by 11.7% ± 2.1% (p = .01). For cortical bone in this slice, the percentage of bone with resorption potential for the osteoporotic bone was greater than the healthy bone by 8.0% ± 1.4% using the hollow-stemmed implant (p = .04). These results suggest a small improvement in bone-implant mechanics using hollow-stemmed humeral implants and indicate osteoporosis could exacerbate stress shielding to some extent. The hollow stems maintained adequate strength and using even thinner walls may further reduce stress shielding. After further developing these models, future studies could yield optimized implant designs tuned for varying bone qualities.
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Affiliation(s)
| | - Amir Tavakoli
- Department of Mechanical and Materials Engineering, Western University, London, Ontario, Canada
| | - G Daniel G Langohr
- School of Biomedical Engineering, Western University, London, Ontario, Canada.,Department of Mechanical and Materials Engineering, Western University, London, Ontario, Canada.,Roth, McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Ontario, Canada
| | - George S Athwal
- Roth, McFarlane Hand & Upper Limb Centre, St. Joseph's Health Care, London, Ontario, Canada
| | - Ryan Willing
- School of Biomedical Engineering, Western University, London, Ontario, Canada.,Department of Mechanical and Materials Engineering, Western University, London, Ontario, Canada
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40
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Vogel D, Henke P, Haenel A, Mokros J, Liebelt M, Bader R. Experimental evaluation of the primary fixation stability of uncemented ceramic hip resurfacing implants. Proc Inst Mech Eng H 2022; 236:9544119211070892. [PMID: 35166142 DOI: 10.1177/09544119211070892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Hip resurfacing arthroplasty is associated with increased frictional moments compared to standard heads owing to their large diameter. High frictional moments may harbor the risk of the implant loosening if the frictional moments exceed the fixation stability of the hip resurfacing arthroplasty. Therefore, the aim of this experimental study was to evaluate the fixation stability of ceramic hip resurfacing implants through a turn-off test. The test specimens, made of alumina toughened zirconia (ATZ) ceramics with an inner titanium-coated surface and square base bodies for better application to the test setup, were pushed on artificial bone materials until a predefined seating depth was achieved. Thereafter, the specimens were turned off from the artificial bone material by using a lever-arm and the turn-off moments were calculated. The density of the artificial bone material utilized (15 and 25 pcf), the press-fit (0.4 and 0.8 mm) and the size of the test specimens varied. The push-on forces ranged from 0.6 ± 0.1 kN to 5.6 ± 0.5 kN depending on the press-fit and artificial bone material. The turn-off moments relied on the respective press-fit, artificial bone material and size of the specimen. They belonged between the range of 8.5 ± 0.4 Nm and 105.4 ± 0.2 Nm. Most of the previously described frictional moments are lower compared to the turn-off moments determined in this study. However, in the worst-case scenario, the turn-off moments of the hip resurfacing implants may be reduced, especially when the adjacent bone stock has a low mineral density.
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Affiliation(s)
- Danny Vogel
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
| | - Paul Henke
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
| | | | - Jan Mokros
- Mathys Orthopaedie GmbH, Moersdorf, Germany
| | | | - Rainer Bader
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
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41
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Inglis B, Schwarzenberg P, Klein K, von Rechenberg B, Darwiche S, Dailey HL. Biomechanical duality of fracture healing captured using virtual mechanical testing and validated in ovine bones. Sci Rep 2022; 12:2492. [PMID: 35169187 PMCID: PMC8847550 DOI: 10.1038/s41598-022-06267-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/17/2022] [Indexed: 01/08/2023] Open
Abstract
Bone fractures commonly repair by forming a bridging structure called callus, which begins as soft tissue and gradually ossifies to restore rigidity to the bone. Virtual mechanical testing is a promising technique for image-based assessment of structural bone healing in both preclinical and clinical settings, but its accuracy depends on the validity of the material model used to assign tissue mechanical properties. The goal of this study was to develop a constitutive model for callus that captures the heterogeneity and biomechanical duality of the callus, which contains both soft tissue and woven bone. To achieve this, a large-scale optimization analysis was performed on 2363 variations of 3D finite element models derived from computed tomography (CT) scans of 33 osteotomized sheep under normal and delayed healing conditions. A piecewise material model was identified that produced high absolute agreement between virtual and physical tests by differentiating between soft and hard callus based on radiodensity. The results showed that the structural integrity of a healing long bone is conferred by an internal architecture of mineralized hard callus that is supported by interstitial soft tissue. These findings suggest that with appropriate material modeling, virtual mechanical testing is a reliable surrogate for physical biomechanical testing.
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Affiliation(s)
- Brendan Inglis
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA, 18015, USA.
| | - Peter Schwarzenberg
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA, 18015, USA
| | - Karina Klein
- Musculoskeletal Research Unit (MSRU), Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland
| | - Brigitte von Rechenberg
- Musculoskeletal Research Unit (MSRU), Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland.,Center for Applied Biotechnology and Molecular Medicine (CABMM), University of Zurich, 8057, Zurich, Switzerland
| | - Salim Darwiche
- Musculoskeletal Research Unit (MSRU), Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland.,Center for Applied Biotechnology and Molecular Medicine (CABMM), University of Zurich, 8057, Zurich, Switzerland
| | - Hannah L Dailey
- Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA, 18015, USA.
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Low-Modulus PMMA Has the Potential to Reduce Stresses on Endplates after Cement Discoplasty. J Funct Biomater 2022; 13:jfb13010018. [PMID: 35225981 PMCID: PMC8883899 DOI: 10.3390/jfb13010018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/20/2022] [Accepted: 01/28/2022] [Indexed: 11/28/2022] Open
Abstract
Cement discoplasty has been developed to treat patients with advanced intervertebral disc degeneration. In discoplasty, poly(methylmethacrylate) (PMMA) bone cement is injected into the disc, leading to reduced pain and certain spinal alignment correction. Standard PMMA-cements have much higher elastic modulus than the surrounding vertebral bone, which may lead to a propensity for adjacent fractures. A PMMA-cement with lower modulus might be biomechanically beneficial. In this study, PMMA-cements with lower modulus were obtained using previously established methods. A commercial PMMA-cement (V-steady®, G21 srl) was used as control, and as base cement. The low-modulus PMMA-cements were modified by 12 vol% (LA12), 16 vol% (LA16) and 20 vol% (LA20) linoleic acid (LA). After storage in 37 °C PBS from 24 h up to 8 weeks, specimens were tested in compression to obtain the material properties. A lower E-modulus was obtained with increasing amount of LA. However, with storage time, the E-modulus increased. Standard and low-modulus PMMA discoplasty were compared in a previously developed and validated computational lumbar spine model. All discoplasty models showed the same trend, namely a substantial reduction in range of motion (ROM), compared to the healthy model. The V-steady model had the largest ROM-reduction (77%), and the LA20 model had the smallest (45%). The average stress at the endplate was higher for all discoplasty models than for the healthy model, but the stresses were reduced for cements with higher amounts of LA. The study indicates that low-modulus PMMA is promising for discoplasty from a mechanical viewpoint. However, validation experiments are needed, and the clinical setting needs to be further considered.
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43
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Injectable bioactive polymethyl methacrylate–hydrogel hybrid bone cement loaded with BMP-2 to improve osteogenesis for percutaneous vertebroplasty and kyphoplasty. Biodes Manuf 2022. [DOI: 10.1007/s42242-021-00172-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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44
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LaMonica JN, Rhee B, Milligan K, Leslie M, Tommasini SM, Wiznia DH. Finite Element Evaluation of the Femoral Neck System as Prophylactic Fixation to Prevent Contralateral Hip Fractures. Geriatr Orthop Surg Rehabil 2022; 13:21514593221135117. [DOI: 10.1177/21514593221135117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/12/2022] Open
Abstract
Introduction Hip fractures cause significant morbidity and mortality for geriatric patients, and incidence is increasing as the population ages. Following a primary hip fracture, up to 20% may suffer a contralateral hip fracture within 5 years despite fracture risk reduction measures, including fall prevention and osteoporosis pharmacologic treatment. The aim of this study is to assess whether insertion of the Femoral Neck System (Depuy Synthes, West Chester, PA) into the contralateral proximal femur may strengthen the bone and decrease the incidence of contralateral hip fractures. Materials and Methods ScanIP, an image processing software was used to produce 3-dimensional models of a cadaver femur with the implanted device. Models were meshed and exported to Abaqus for finite element analysis to evaluate the device’s ability to reduce stress in the proximal femur. Results were analyzed for element-wise volume and von-Mises stresses. Results The implant reduced peak stress and bone failure at all levels of bone quality. Specifically in osteoporotic bone, the implant decreased peak stress by 27%, proximal femur trabecular bone failure by 5% and cortical bone failure by 100% in the femoral neck. Conclusions Our results from computer generated finite element analyses indicate that the Femoral Neck System may strengthen an osteoporotic proximal femur in the event of a lateral fall. Further investigation with expanded finite element analysis and cadaveric biomechanical studies are needed to validate these results.
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Affiliation(s)
- Julia N. LaMonica
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
- Quinnipiac University, Frank H. Netter M.D. School of Medicine, North Haven, CT, USA
| | - Brian Rhee
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
| | - Kenneth Milligan
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
| | - Michael Leslie
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
| | - Steven M. Tommasini
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
| | - Daniel H. Wiznia
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT, USA
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Hennicke NS, Saemann M, Kluess D, Bader R, Sander M. Subject specific finite element modelling of periprosthetic femoral fractures in different load cases. J Mech Behav Biomed Mater 2021; 126:105059. [PMID: 34995835 DOI: 10.1016/j.jmbbm.2021.105059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 11/19/2022]
Abstract
Periprosthetic femoral fractures (PFF) around total hip replacements are one of the biggest challenges for orthopaedic surgeons. To understand the risk factors and formation of these fractures, the development of a reliable finite element (FE) model incorporating bone failure is essential. Due to the anisotropic and complex hierarchical structure of bone, the mechanical behaviour under large strains is difficult to predict. In this study, a state-of-the-art subject specific FE modelling technique for bone is utilised to generate and investigate PFF. A bilinear constitutive law is applied to bone tissue in subject specific FE models of five human femurs which are virtually implanted with a straight hip stem to numerically analyse PFF. The material parameters of the models are expressed as a function of bone ash density and mapped node wise to the FE mesh. In this way the subject specific, heterogeneous structure of bone is mimicked. For material mapping of the parameters, computed tomography (CT) images of the original fresh-frozen femurs are used. Periprosthetic fractures are generated by deleting elements on the basis of a critical plastic strain failure criterion. The models are analysed under physiological and clinically relevant conditions in two different load cases re-enacting stumbling and a sideways fall on the hip. The results of the analyses are quantified with experimental data from previous work. With regard to fracture pattern, stiffness and failure load the simulations of the load case stumbling delivered the most stable and accurate results. In general, mapping of material properties was found to be an appropriate way to reproduce PFF with finite element models.
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Affiliation(s)
- N S Hennicke
- Institute of Structural Mechanics, University of Rostock, Albert-Einstein-Str. 2, 18059, Rostock, Germany.
| | - M Saemann
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
| | - D Kluess
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
| | - R Bader
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany
| | - M Sander
- Institute of Structural Mechanics, University of Rostock, Albert-Einstein-Str. 2, 18059, Rostock, Germany
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Ramírez-Vela V, Aguilar-Pérez LA, Paredes-Rojas JC, Flores-Campos JA, Ortiz-Hernández FEL, Torres-SanMiguel CR. Bone Fractures Numerical Analysis in a Femur Affected by Osteogenesis Imperfecta. CHILDREN (BASEL, SWITZERLAND) 2021; 8:children8121177. [PMID: 34943373 PMCID: PMC8700594 DOI: 10.3390/children8121177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
This work presents a non-invasive methodology to obtain a three-dimensional femur model of three-year-old infants affected with Osteogenesis Imperfecta (OI) type III. DICOM® Files of a femur were processed to obtain a finite element model to assess the transverse, the oblique, and the comminuted fractures. The model is evaluated under a normal walking cycle. The loads applied were considered the most critical force generated on the normal walking cycle, and the analyses considered anisotropic bone conditions. The outcome shows stress concentration areas in the central zone of the diaphysis of the femur, and the highest levels of stress occur in the case of the comminuted fracture, while the transverse fracture presents the lowest values. Thus, the method can be helpful for determining the bone fracture behavior of certain pathologies, such as osteogenesis imperfecta, osteopenia, and osteoporosis.
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Affiliation(s)
- Viridiana Ramírez-Vela
- Instituto Politécnico Nacional, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco, Sección de Estudios de Posgrado e Investigación, Ciudad de Mexico 07738, Mexico; (V.R.-V.); (L.A.A.-P.)
| | - Luis Antonio Aguilar-Pérez
- Instituto Politécnico Nacional, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco, Sección de Estudios de Posgrado e Investigación, Ciudad de Mexico 07738, Mexico; (V.R.-V.); (L.A.A.-P.)
| | - Juan Carlos Paredes-Rojas
- Instituto Politécnico Nacional, Centro Mexicano para la Producción más Limpia, Ciudad de Mexico 07340, Mexico;
| | - Juan Alejandro Flores-Campos
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas, Ciudad de Mexico 07340, Mexico;
| | - Fernando ELi Ortiz-Hernández
- Instituto Politécnico Nacional, Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Culhuacán, Ciudad de Mexico 04260, Mexico;
| | - Christopher René Torres-SanMiguel
- Instituto Politécnico Nacional, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco, Sección de Estudios de Posgrado e Investigación, Ciudad de Mexico 07738, Mexico; (V.R.-V.); (L.A.A.-P.)
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Rhee B, Tommasini SM, Milligan K, Moulton J, Leslie M, Wiznia DH. Finite Element Analysis of Cannulated Screws as Prophylactic Intervention of Hip Fractures. Geriatr Orthop Surg Rehabil 2021; 12:21514593211055890. [PMID: 34868723 PMCID: PMC8637371 DOI: 10.1177/21514593211055890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Introduction The frequency of hip fractures, a major cause of morbidity and mortality for geriatric patients, is expected to increase exponentially in the next few decades. The aim of this study is to assess the ability of stainless-steel cannulated screws to reduce the risk of a femoral neck fracture, if placed prophylactically prior to a fall. Materials and Methods We created finite element models from computed tomography (CT) scan-based 3D models of a geriatric patient through 3D-image processing and model generation software. We used linear finite element simulations to analyze the effect of cannulated screws in the proximal femur in single-leg stance and lateral fall, which were processed for peak von Mises stresses and element failure. Findings Prophylactically placed cannulated screws significantly reduced failure in an osteoporotic proximal femur undergoing lateral fall. Three implanted screws in an inverted triangle formation decreased proximal femoral trabecular failure by 21% and cortical failure by 5%. This reduction in failure was achieved with a 55% decrease in femoral neck failure and 14% in lateral cortex failure. Conclusion Our results indicate that cannulated hip screws in an inverted triangle formation may strengthen an osteoporotic proximal femur in the event of a lateral fall. Mechanical testing on cadaveric or composite models is required to validate these results.
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Affiliation(s)
- Brian Rhee
- Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Julia Moulton
- Quinnipiac University Frank H. Netter M.D. School of Medicine, North Haven, CT, USA
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Zheng L, Chen X, Zheng Y, He X, Wu J, Lin Z. Cement augmentation of the proximal femoral nail antirotation for the treatment of two intertrochanteric fractures - a comparative finite element study. BMC Musculoskelet Disord 2021; 22:1010. [PMID: 34856965 PMCID: PMC8641168 DOI: 10.1186/s12891-021-04878-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/16/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There are concerns regarding initial stability and cutout effect in proximal femoral nail antirotation (PFNA) treating intertrochanteric fractures. No study have used finite element analysis (FEA) to investigate the biomechanics. This study aimed to compare the cutout effect, stress and displacement between stable (AO31-A1.3) and unstable (AO31-A2.2) intertrochanteric fractures treated by cement augmented PFNA. METHODS Four femoral finite element models (FEMs) were constructed and tested under the maximum loading during walking. Non-augmented and augmented PFNA in two different intertrochanteric fractures were respectively simulated, assuming Tip Apex Distance (TAD) < 25 mm within each FEM. The cutout effect, stress and displacement between femur and PFNA were compared in each condition. RESULTS Cutout effect was observed in both non-augmented femoral head and was more apparently in unstable intertrochanteric fracture model. After reinforced by bone cement, no cutout effect occurred in two models. Stress concentration were observed on medial part of intertrochanteric region and the proximal part of helical blade before augmented while were observed on femoral shaft and the conjunction between blade and nail after augmented in both FEMs. Displacement mainly appeared on femoral head and the helical blade tip before augmented while distributed moderately on intertrochanteric region and the upper part of nail after augmented in both FEMs. The maximum stress and displacement value of femur decreased both in stable and unstable model after augmented but was more significantly in the unstable one. The maximum stress and displacement value of PFNA increased both in stable and unstable model after augmented but was more significantly in the unstable one. CONCLUSION Our FEA study indicated that the cement augmentation of the PFNA biomechanically enhances the cutout resistance in intertrochanteric fracture, this procedure is especially efficient for the unstable intertrochanteric fracture.
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Affiliation(s)
- Liqin Zheng
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Xinmin Chen
- Department of Orthopedic, Zhongxiang People's Hospital, Jingmen, Hubei, China
| | - Yongze Zheng
- Department of Orthopedic, Puning Hospital of Traditional Chinese Medicine, Jieyang, Guangdong, China
| | - Xingpeng He
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Jingxiong Wu
- Department of Osteoarticular Surgery, Integrated Traditional Chinese and Western Medicine Hospital of Pengjiang District of Jiangmen City, Jiangmen, Guangdong, China.
| | - Ziling Lin
- Department of Orthopedic, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China.
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Öhman‐Mägi C, Holub O, Wu D, Hall RM, Persson C. Density and mechanical properties of vertebral trabecular bone-A review. JOR Spine 2021; 4:e1176. [PMID: 35005442 PMCID: PMC8717096 DOI: 10.1002/jsp2.1176] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 10/14/2021] [Accepted: 10/20/2021] [Indexed: 11/16/2022] Open
Abstract
Being able to predict the mechanical properties of vertebrae in patients with osteoporosis and other relevant pathologies is essential to prevent fractures and to develop the most favorable fracture treatments. Furthermore, a reliable prediction is important for developing more patient- and pathology-specific biomaterials. A plethora of studies correlating bone density to mechanical properties has been reported; however, the results are variable, due to a variety of factors, including anatomical site and methodological differences. The aim of this study was to provide a comprehensive literature review on density and mechanical properties of human vertebral trabecular bone as well as relationships found between these properties. A literature search was performed to include studies, which investigated mechanical properties and bone density of trabecular bone. Only studies on vertebral trabecular bone tissue, reporting bone density or mechanical properties, were kept. A large variation in reported vertebral trabecular bone densities, mechanical properties, and relationships between the two was found, as exemplified by values varying between 0.09 and 0.35 g/cm3 for the wet apparent density and from 0.1 to 976 MPa for the elastic modulus. The differences were found to reflect variations in experimental and analytical processes that had been used, including testing protocol and specimen geometry. The variability in the data decreased in studies where bone tissue testing occurred in a standardized manner (eg, the reported differences in average elastic modulus decreased from 400% to 10%). It is important to take this variability into account when analyzing the predictions found in the literature, for example, to calculate fracture risk, and it is recommended to use the models suggested in the present review to reduce data variability.
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Affiliation(s)
- Caroline Öhman‐Mägi
- Department of Materials Science and EngineeringUppsala UniversityUppsalaSweden
| | - Ondrej Holub
- School of Mechanical EngineeringUniversity of LeedsLeedsUK
| | - Dan Wu
- Department of Materials Science and EngineeringUppsala UniversityUppsalaSweden
| | | | - Cecilia Persson
- Department of Materials Science and EngineeringUppsala UniversityUppsalaSweden
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50
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Bone Organic-Inorganic Phase Ratio Is a Fundamental Determinant of Bone Material Quality. Appl Bionics Biomech 2021; 2021:4928396. [PMID: 34754330 PMCID: PMC8572605 DOI: 10.1155/2021/4928396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 10/02/2021] [Accepted: 10/21/2021] [Indexed: 11/17/2022] Open
Abstract
Background Bone mineral density is widely used by clinicians for screening osteoporosis and assessing bone strength. However, its effectiveness has been reported unsatisfactory. In this study, it is demonstrated that bone organic-inorganic phase ratio is a fundamental determinant of bone material quality measured by stiffness, strength, and toughness. Methods and Results Two-hundred standard bone specimens were fabricated from bovine legs, with a specialized manufacturing method that was designed to reduce the effect of bone anisotropy. Bone mechanical properties of the specimens, including Young's modulus, yield stress, peak stress, and energy-to-failure, were measured by mechanical testing. Organic and inorganic mass contents of the specimens were then determined by bone ashing. Bone density and organic-inorganic phase ratio in the specimens were calculated. Statistical methods were applied to study relationships between the measured mechanical properties and the organic-inorganic phase ratios. Statistical characteristics of organic-inorganic phase ratios in the specimens with top material quality were investigated. Bone organic-inorganic phase ratio had strong Spearman correlation with bone material properties. Bone specimens that had the highest material quality had a very narrow scope of organic-inorganic phase ratio, which could be considered as the “optimal” ratio among the tested specimens. Conclusion Bone organic-inorganic phase ratio is a fundamental determinant of bone material quality. There may exist an “optimal” ratio for the bone to achieve top material quality. Deviation from the “optimal” ratio is probably the fundamental cause of various bone diseases. This study suggests that bone organic-inorganic phase ratio should be considered in clinical assessment of fracture risk.
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