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Wodarek J, Ostrander J, Atkinson P, Atkinson T. Should a low starting point be abandoned for cannulated screw fixation of femoral neck fractures? Comput Methods Biomech Biomed Engin 2024:1-13. [PMID: 38943377 DOI: 10.1080/10255842.2024.2372619] [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: 03/06/2023] [Accepted: 06/19/2024] [Indexed: 07/01/2024]
Abstract
A validated femoral neck fracture model stabilized with three inverted cannulated screws was used to consider different intraoperative scenarios when the inferior screw hole is inadvertently started too inferiorly. These scenarios were to: (1) abandon the misplaced inferior screw hole and restart this hole more proximally, or (2) accept the mispositioned placement of the inferior screw and insert the remaining superior screws parallel or convergent to the inferior screw. Utilizing the second option and accepting the errant hole was associated with the greatest interfragmentary motion and stresses in the bone and hardware. In contrast, the first option created an improved mechanical environment for healing.
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2
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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] [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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3
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Zdero R, Brzozowski P, Schemitsch EH. Biomechanical properties of artificial bones made by Sawbones: A review. Med Eng Phys 2023; 118:104017. [PMID: 37536838 DOI: 10.1016/j.medengphy.2023.104017] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 08/05/2023]
Abstract
Biomedical engineers and physicists frequently use human or animal bone for orthopaedic biomechanics research because they are excellent approximations of living bone. But, there are drawbacks to biological bone, like degradation over time, ethical concerns, high financial costs, inter-specimen variability, storage requirements, supplier sourcing, transportation rules, etc. Consequently, since the late 1980s, the Sawbones® company has been one of the world's largest suppliers of artificial bones for biomechanical testing that counteract many disadvantages of biological bone. There have been many published reports using these bone analogs for research on joint replacement, bone fracture fixation, spine surgery, etc. But, there exists no prior review paper on these artificial bones that gives a comprehensive and in-depth look at the numerical data of interest to biomedical engineers and physicists. Thus, this paper critically reviews 25 years of English-language studies on the biomechanical properties of these artificial bones that (a) characterized unknown or unreported values, (b) validated them against biological bone, and/or (c) optimized different design parameters. This survey of data, advantages, disadvantages, and knowledge gaps will hopefully be useful to biomedical engineers and physicists in developing mechanical testing protocols and computational finite element models.
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Affiliation(s)
- Radovan Zdero
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada
| | - Pawel Brzozowski
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada.
| | - Emil H Schemitsch
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada; Division of Orthopaedic Surgery, Western University, London, ON, Canada
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4
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Baleani M, Fraterrigo G, Erani P, Rota G, Berni M, Taddei F, Schileo E. Applying a homogeneous pressure distribution to the upper vertebral endplate: Validation of a new loading system, pilot application to human vertebral bodies, and finite element predictions of DIC measured displacements and strains. J Mech Behav Biomed Mater 2023; 140:105706. [PMID: 36841124 DOI: 10.1016/j.jmbbm.2023.105706] [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: 12/12/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
Image-based personalized Finite Element Models (pFEM) could detect alterations in physiological deformation of human vertebral bodies, but their accuracy has been seldom reported. Meaningful validation experiments should allow vertebral endplate deformability and ensure well-controlled boundary conditions. This study aimed to (i) validate a new loading system to apply a homogeneous pressure on the vertebral endplate during vertebral body compression regardless of endplate deformation; (ii) perform a pilot study on human vertebral bodies measuring surface displacements and strains with Digital Image Correlation (DIC); (iii) determine the accuracy of pFEM of the vertebral bodies. Homogeneous pressure application was achieved by pressurizing a fluid silicone encased in a rubber silicone film acting on the cranial endplate. The loading system was validated by comparing DIC-measured longitudinal strains and lower-end contact pressures, measured on three homogeneous pseudovertebrae of constant transversal section at 2.0 kN, against theoretically calculated values. Longitudinal strains and contact pressures were rather homogeneous, and their mean values close to theoretical calculations (5% underestimation). DIC measurements of surface longitudinal and circumferential displacements and strains were obtained on three human vertebral bodies at 2.0 kN. Complete displacement and strain maps were achieved for anterolateral aspects with random errors ≤0.2 μm and ≤30 μstrain, respectively. Venous plexus and double curvatures limited the completeness and accuracy of DIC data in posterior aspects. pFEM of vertebral bodies, including cortical bone mapping, were built from computed tomography images. In anterolateral aspects, pFEM accuracy of the three vertebrae was: (i) comparable to literature in terms of longitudinal displacements (R2>0.8); (ii) extended to circumferential displacements (pooled data: R2>0.9) and longitudinal strains (zero median error, 95% error: <27%). Circumferential strains were overestimated (median error: 39%). The new methods presented may permit to study how physiological and pathologic conditions influence the ability of vertebral endplates/bodies to sustain loads.
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Affiliation(s)
- Massimiliano Baleani
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy.
| | - Giulia Fraterrigo
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy
| | - Paolo Erani
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Giulia Rota
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Matteo Berni
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Fulvia Taddei
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy
| | - Enrico Schileo
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy.
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5
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Nesbitt DQ, Burruel DE, Henderson BS, Lujan TJ. Finite element modeling of meniscal tears using continuum damage mechanics and digital image correlation. Sci Rep 2023; 13:4039. [PMID: 36899069 PMCID: PMC10006193 DOI: 10.1038/s41598-023-29111-z] [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: 07/25/2022] [Accepted: 01/31/2023] [Indexed: 03/12/2023] Open
Abstract
Meniscal tears are a common, painful, and debilitating knee injury with limited treatment options. Computational models that predict meniscal tears may help advance injury prevention and repair, but first these models must be validated using experimental data. Here we simulated meniscal tears with finite element analysis using continuum damage mechanics (CDM) in a transversely isotropic hyperelastic material. Finite element models were built to recreate the coupon geometry and loading conditions of forty uniaxial tensile experiments of human meniscus that were pulled to failure either parallel or perpendicular to the preferred fiber orientation. Two damage criteria were evaluated for all experiments: von Mises stress and maximum normal Lagrange strain. After we successfully fit all models to experimental force-displacement curves (grip-to-grip), we compared model predicted strains in the tear region at ultimate tensile strength to the strains measured experimentally with digital image correlation (DIC). In general, the damage models underpredicted the strains measured in the tear region, but models using von Mises stress damage criterion had better overall predictions and more accurately simulated experimental tear patterns. For the first time, this study has used DIC to expose strengths and weaknesses of using CDM to model failure behavior in soft fibrous tissue.
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Affiliation(s)
- Derek Q Nesbitt
- Biomedical Engineering Doctoral Program, Boise State University, Boise, ID, USA
| | - Dylan E Burruel
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA
| | - Bradley S Henderson
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA
| | - Trevor J Lujan
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA.
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6
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Ideal Configuration Distribution of Femoral Neck Cannulated Screw in High Altitude Population: A Finite Element Study. BIOMED RESEARCH INTERNATIONAL 2022; 2022:2085378. [DOI: 10.1155/2022/2085378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022]
Abstract
Objective. For people in high altitude areas, the shape of the femoral neck is different due to the different living environment. To deduce the optimal insertion angle and position of the cannulated screw using three-dimensional finite element technology in patients at high altitude. Methods. The data of 100 volunteers were used to establish a finite element model. The stress and displacement of cannulated screws of equilateral and oblique triangle screw placement in femoral neck fracture model and complete femoral neck model were evaluated. Results. On the narrowest plane, the average values of
, B, and C were 47.63o, 75.49o, and 56.88o, respectively, and the shape was an oblique triangle. In complete femoral neck model, the maximum Von Mises stress of the three cannulated screws of equilateral triangle screw placement was slightly larger than oblique triangle screw placement, and this difference was more obvious in femoral neck fracture model. Under same loads, the overall maximum displacement of femur in oblique triangle screw placement was less than equilateral triangle screw placement in two models. Conclusions. For people in high-altitude areas, the three screws should be implanted in an oblique triangle configuration in cannulated screw treatment of femoral neck fractures.
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7
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Experimental validation of a subject-specific finite element model of lumbar spine segment using digital image correlation. PLoS One 2022; 17:e0272529. [PMID: 36084092 PMCID: PMC9462677 DOI: 10.1371/journal.pone.0272529] [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: 01/14/2022] [Accepted: 07/20/2022] [Indexed: 11/23/2022] Open
Abstract
Pathologies such as cancer metastasis and osteoporosis strongly affect the mechanical properties of the vertebral bone and increase the risk of fragility fractures. The prediction of the fracture risk with a patient-specific model, directly generated from the diagnostic images of the patient, could help the clinician in the choice of the correct therapy to follow. But before such models can be used to support any clinical decision, their credibility must be demonstrated through verification, validation, and uncertainty quantification. In this study we describe a procedure for the generation of such patient-specific finite element models and present a first validation of the kinematics of the spine segment. Quantitative computed tomography images of a cadaveric lumbar spine segment presenting vertebral metastatic lesions were used to generate the model. The applied boundary conditions replicated a specific experimental test where the spine segment was loaded in compression-flexion. Model predictions in terms of vertebral surface displacements were compared against the full-field experimental displacements measured with Digital Image Correlation. A good agreement was obtained from the local comparison between experimental data and simulation results (R2 > 0.9 and RMSE% <8%). In conclusion, this work demonstrates the possibility to apply the developed modelling pipeline to predict the displacement field of human spine segment under physiological loading conditions, which is a first fundamental step in the credibility assessment of these clinical decision-support technology.
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8
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Biomechanical Assessment of Cannulated Nails for the Treatment of Proximal Femur Fractures. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This article focuses on a type of surgical implant used in orthopaedics and traumatology—cannulated femoral nails. Femoral nails are used in medical treatment for purposes of osteosynthesis, i.e., when treating various types of complicated fractures, in this case fractures of the femur. The article investigates cases in which a nail has been implanted in the proximal part of the femur for a short time (with the fracture still not healed), compared with cases in which the bone has already healed. According to AO classification, examined fractures are described as AO 31B3 AO 32A3. The main focus is on strength-deformation analysis using the finite element method (FEM), which makes it possible to determine the behaviour of the femur-implant system. FEM analysis was used to compare 1.4441 steel nails made by two manufacturers, Medin (Czech Republic) and Tantum (Germany). Boundary conditions including external loading, prescribed supports and elastic foundation are defined. There were solved FEM analyses for five cases of healed femur and five cases of broken femur both including implants with prescribed collo-diaphyseal angles. The results of the analysis were used to assess stress-deformation states from the perspective of appropriateness for clinical treatment, biomechanical reliability and safety. All examined femoral nails are compared, safe and suitable for patient treatment.
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Cui Y, Xiang D, Shu L, Duan Z, Liao Z, Wang S, Liu W. Incremental Element Deletion-Based Finite Element Analysis of the Effects of Impact Speeds, Fall Postures, and Cortical Thicknesses on Femur Fracture. MATERIALS 2022; 15:ma15082878. [PMID: 35454571 PMCID: PMC9025544 DOI: 10.3390/ma15082878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 02/05/2023]
Abstract
The proximal femur’s numerical simulation could give an effective method for predicting the risk of femoral fracture. However, the majority of existing numerical simulations is static, which does not correctly capture the dynamic properties of bone fractures. On the basis of femoral fracture analysis, a dynamic simulation using incremental element deletion (IED)-based finite element analysis (FEA) was developed and compared to XFEM in this study. Mechanical tests were also used to assess it. Different impact speeds, fall postures, and cortical thicknesses were also studied for their implications on fracture types and mechanical responses. The time it took for the crack to shatter was shorter when the speed was higher, and the crack line slid down significantly. The fracture load fell by 27.37% when the angle was altered from 15° to 135°, indicating that falling forward was less likely to cause proximal femoral fracture than falling backward. Furthermore, the model with scant cortical bone was susceptible to fracture. This study established a theoretical foundation and mechanism for forecasting the risk of proximal femoral fracture in the elderly.
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Affiliation(s)
- Yangyang Cui
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Y.C.); (Z.D.)
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110057, China
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Dingding Xiang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110057, China
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Correspondence: (D.X.); (S.W.); (W.L.)
| | - Liming Shu
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo, Tokyo 1138656, Japan;
| | - Zhili Duan
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Y.C.); (Z.D.)
| | - Zhenhua Liao
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Song Wang
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Correspondence: (D.X.); (S.W.); (W.L.)
| | - Weiqiang Liu
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (Y.C.); (Z.D.)
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Correspondence: (D.X.); (S.W.); (W.L.)
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10
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A novel specimen shape for measurement of linear strain fields by means of digital image correlation. Sci Rep 2021; 11:17515. [PMID: 34471200 PMCID: PMC8410939 DOI: 10.1038/s41598-021-97085-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/13/2021] [Indexed: 11/08/2022] Open
Abstract
Strains on the surface of engineering structures or biological tissues are non-homogeneous. These strain fields can be captured by means of Digital Image Correlation (DIC). However, DIC strain field measurements are prone to noise and filtering of these fields influences measured strain gradients. This study aims to design a novel tensile test specimen showing two linear gradients, to measure full-field linear strain measurements on the surface of test specimens, and to investigate the accuracy of DIC strain measurements globally (full-field) and locally (strain gauges' positions), with and without filtering of the DIC strain fields. Three materials were employed for this study: aluminium, polymer, and bovine bone. Normalized strain gradients were introduced that are load independent and evaluated at two local positions showing 3.6 and 6.9% strain change per mm. Such levels are typically found in human bones. At these two positions, two strain gauges were applied to check the experimental strain magnitudes. A third strain gauge was applied to measure the strain in a neutral position showing no gradient. The accuracy of the DIC field measurement was evaluated at two deformation stages (at [Formula: see text] 500 and 1750 μstrain) using the root mean square error (RMSE). The RMSE over the two linear strain fields was less than 500 μstrain for both deformation stages and all materials. Gaussian low-pass filter (LPF) reduced the DIC noise between 25% and 64% on average. As well, filtering improved the accuracy of the local normalized strain gradients measurements with relative difference less than 20% and 12% for the high- and low-gradient, respectively. In summary, a novel specimen shape and methodological approach are presented which are useful for evaluating and improving the accuracy of the DIC measurement where non-homogeneous strain fields are expected such as on bone tissue due to their hierarchical structure.
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Kok J, Grassi L, Gustafsson A, Isaksson H. Femoral strength and strains in sideways fall: Validation of finite element models against bilateral strain measurements. J Biomech 2021; 122:110445. [PMID: 33933857 DOI: 10.1016/j.jbiomech.2021.110445] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 02/15/2021] [Accepted: 04/12/2021] [Indexed: 11/29/2022]
Abstract
Low impact falls to the side are the main cause of hip fractures in elderly. Finite element (FE) models of the proximal femur may help in the assessment of patients at high risk for a hip fracture. However, extensive validation is essential before these models can be used in a clinical setting. This study aims to use strain measurements from bilateral digital image correlation to validate an FE model against ex vivo experimental data of proximal femora under a sideways fall loading condition. For twelve subjects, full-field strain measurements were available on the medial and lateral side of the femoral neck. In this study, subject-specific FE models were generated based on a consolidated procedure previously validated for stance loading. The material description included strain rate dependency and separate yield and fracture strain limits in tension and compression. FE predicted fracture force and experimentally measured peak forces showed a strong correlation (R2 = 0.92). The FE simulations predicted the fracture initiation within 3 mm distance of the experimental fracture line for 8/12 subjects. The predicted and measured strains correlated well on both the medial side (R2 = 0.87) and the lateral side (R2 = 0.74). The lower correlation on the lateral side is attributed to the irregularity of the cortex and presence of vessel holes in this region. The combined validation against bilateral full-field strain measurements and peak forces has opened the door for a more elaborate qualitative and quantitative validation of FE models of femora under sideways fall loading.
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Affiliation(s)
- Joeri Kok
- Department of Biomedical Engineering, Lund University, Sweden.
| | - Lorenzo Grassi
- Department of Biomedical Engineering, Lund University, Sweden
| | - Anna Gustafsson
- Department of Biomedical Engineering, Lund University, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Sweden
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Huang H, Feng Z, Wang W, Yang C, Liao J, Ouyang J. Finite Element Analysis of Femoral Neck Fracture Treated with Bidirectional Compression-Limited Sliding Screw. Med Sci Monit 2021; 27:e929163. [PMID: 33782376 PMCID: PMC8019266 DOI: 10.12659/msm.929163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background The rate of femoral neck shortening after internal fixation for femoral neck fracture is high and this complication reduces the function of the affected lower limb. The aim of this study was to design a bidirectional compression-limited sliding screw (BCLSC) that can achieve a full balance between retaining the sliding pressure of the ends of and maintaining the length of the femoral neck. Material/Methods We constructed a 3-dimensional model of a Pauwels III femoral neck fracture and models of 3 internal fixation methods (3 cannulated screws [3CS], dynamic hip screw [DHS]+CS, and BCLSC) by finite element analysis (FEA).The finite element model simulated the loading of the human body when standing on 1 leg. Displacement and stress distribution of the models were calculated based on an axial stress of 600 N. Results The peak von Mises stress (VMS) values of fracture ends in the 3CS, DHS+CS and BCLSC groups were 94.687 MPa, 26.375 MPa and 45.698 MPa; the peak VMS values of internal fixed stress were 451.53 MPa, 174.45 MPa, and 337.34 MPa; the peak VMS values of the lateral femoral wall were 70.021 MPa, 53.033 MPa, and 20.009 MPa; maximum displacements of the femoral head were 1.4482 mm, 1.3813 mm, and 1.3889 mm; and the internal fixed displacement peaks were 4.1134 mm, 3.91 mm, and 4.1004 mm, respectively. Conclusions The FEA showed that compared with the CS, the new BCLSC showed better performance in resisting shearing force for Pauwels III femoral neck fracture, with better mechanical properties. These data provide a basis for further experiments and clinical application.
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Affiliation(s)
- Hai Huang
- Department of Anatomy, School of Basic Medical Science, University and Guangdong Provincial Key Laboratory of Medical Biomechanics and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China (mainland).,Department of Traumatic Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China (mainland)
| | - Zhengkuan Feng
- Department of Anatomy, School of Basic Medical Science, Southern Medical University and Guangdong Provincial Key Laboratory of Medical Biomechanics and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China (mainland)
| | - Weifei Wang
- The Hospital of South China Normal University, Guangzhou, Guangdong, China (mainland)
| | - Cheng Yang
- Department of Traumatic Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China (mainland)
| | - Jianwen Liao
- Department of Traumatic Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China (mainland)
| | - Jun Ouyang
- Department of Anatomy, School of Basic Medical Science, Southern Medical University and Guangdong Provincial Key Laboratory of Medical Biomechanics and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China (mainland)
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13
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Bird G, Glyde M, Hosgood G, Hayes A, Day R. Biomechanical Comparison of a Notched Head Locking T-Plate and a Straight Locking Compression Plate in a Juxta-Articular Fracture Model. Vet Comp Orthop Traumatol 2020; 34:161-170. [PMID: 33249549 DOI: 10.1055/s-0040-1719166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE This investigation compared the biomechanical properties of a 2.0 mm locking compression notched head T-plate (NHTP) and 2.0 mm straight locking compression plate (LCP), in a simple transverse juxta-articular fracture model. STUDY DESIGN Two different screw configurations were compared for the NHTP and LCP, modelling short (configuration 1) and long working length (configuration 2). Constructs were tested in compression, perpendicular and tension non-destructive four point bending and torsion. Plate surface strain was measured at 12 regions of interest (ROI) using three-dimensional digital image correlation. Stiffness and strain were compared between screw configurations within and between each plate. RESULTS The LCP was stiffer than the NHTP in all three planes of bending and torsion (p < 0.05). The NHTP had greater strain than the LCP during compression bending and torsion at all ROI (p < 0.0005). The short working length was stiffer in all three planes of bending and in torsion (p < 0.05) than the longer working length for both plates. The long working length showed greater strain than the short working length at most ROI. CONCLUSION In this experimental model, a 2.0 mm LCP with two screws in the short fragment was significantly stiffer and had lower plate strain than a 2.0 mm NHTP with three screws in the short fragment. Extending the working length significantly reduced construct stiffness and increased plate strain. These findings may guide construct selection.
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Affiliation(s)
- Guy Bird
- College of Veterinary Medicine, Murdoch University, Perth, Australia
| | - Mark Glyde
- College of Veterinary Medicine, Murdoch University, Perth, Australia
| | - Giselle Hosgood
- College of Veterinary Medicine, Murdoch University, Perth, Australia
| | - Alex Hayes
- Department of Medical Engineering and Physics, Royal Perth Hospital, Perth, Australia
| | - Robert Day
- Department of Medical Engineering and Physics, Royal Perth Hospital, Perth, Australia
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14
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Aycock KI, Weaver JD, Paranjape HM, Senthilnathan K, Bonsignore C, Craven BA. Full-field microscale strain measurements of a nitinol medical device using digital image correlation. J Mech Behav Biomed Mater 2020; 114:104221. [PMID: 33309001 DOI: 10.1016/j.jmbbm.2020.104221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 07/06/2020] [Accepted: 11/20/2020] [Indexed: 10/22/2022]
Abstract
Computational modeling and simulation are commonly used during the development of cardiovascular implants to predict peak strains and strain amplitudes and to estimate the associated durability and fatigue life of these devices. However, simulation validation has historically relied on comparison with surrogate quantities like force and displacement due to barriers to direct strain measurement-most notably, the small spatial scale of these devices. We demonstrate the use of microscale two-dimensional digital image correlation (2D-DIC) to directly characterize full-field surface strains on a nitinol medical device coupon under emulated physiological and hyperphysiological loading. Experiments are performed using a digital optical microscope and a custom, temperature-controlled load frame. Following applicable recommendations from the International DIC Society, hardware and environmental heating studies, noise floor analyses, and in- and out-of-plane rigid body translation studies are first performed to characterize the microscale DIC setup. Uniaxial tension experiments are also performed using a polymeric test specimen to characterize the strain accuracy of the approach up to nominal stains of 5%. Sub-millimeter fields of view and sub-micron displacement accuracies (9nm mean error) are achieved, and systematic (mean) and random (standard deviation) errors in strain are each estimated to be approximately 1,000μϵ. The system is then demonstrated by acquiring measurements at the root of a 300μm-wide nitinol medical device strut undergoing fixed-free cantilever bending motion. Lüders-like transformation bands are observed originating from the tensile side of the strut that spread toward the neutral axis at an angle of approximately 55°. Despite the inherent limitations of optical microscopy and 2D-DIC, simple and relatively economical setups like that demonstrated herein could provide a practical and accessible solution for characterizing cardiovascular implant micromechanics, validating computational model strain predictions, and guiding the development of next-generation material models for simulating superelastic nitinol.
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Affiliation(s)
- Kenneth I Aycock
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD 20993, United States of America.
| | - Jason D Weaver
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD 20993, United States of America
| | - Harshad M Paranjape
- Confluent Medical Technologies, Inc. 47533 Westinghouse Drive, Fremont, CA 94539, United States of America
| | - Karthikeyan Senthilnathan
- Confluent Medical Technologies, Inc. 47533 Westinghouse Drive, Fremont, CA 94539, United States of America
| | - Craig Bonsignore
- Confluent Medical Technologies, Inc. 47533 Westinghouse Drive, Fremont, CA 94539, United States of America
| | - Brent A Craven
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD 20993, United States of America
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15
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Medial support nail and proximal femoral nail antirotation in the treatment of reverse obliquity inter-trochanteric fractures (Arbeitsgemeinschaft fur Osteosynthesfrogen/Orthopedic Trauma Association 31-A3.1): a finite-element analysis. Chin Med J (Engl) 2020; 133:2682-2687. [PMID: 32889910 PMCID: PMC7647506 DOI: 10.1097/cm9.0000000000001031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The reverse obliquity inter-trochanteric fracture is a distinct fracture pattern that is mechanically different from most inter-trochanteric fractures and the optional treatment of it is still controversial. The purpose of this study was to compare differences in the efficacy of a novel nail (medial support nail [MSN-II]) and proximal femoral nail anti-rotation (PFNA-II) in the treatment of reverse obliquity inter-trochanteric fractures (Arbeitsgemeinschaft fur Osteosynthesfrogen/Orthopedic Trauma Association [AO/OTA] 31-A3.1) using finite-element analysis. METHODS Modeling software was used to establish a three-dimensional model of MSN-II and PFNA-II and an A3.1 inter-trochanteric fracture model. Abaqus software was used to implement different force loads to compare finite-element biomechanical parameters such as the maximum stress in implant and the displacement of fracture site. RESULTS The femoral stress, implant stress and fracture site displacement of MSN-II was less than that of PFNA-II. The results indicated that the maximal femoral stress was 581 MPa for PFNA-II and 443 MPa for the MSN-II. The maximum stress values in the PFNA-II and MSN-II models were 291 and 241 MPa, respectively. The maximal displacements of the fracture site were 1.47 and 1.16 mm in the PFNA-II and MSN-II models, respectively. CONCLUSION Compared with PFNA-II for inter-trochanteric fracture (AO/OTA 31-A3.1), MSN-II which was designed with a triangular stability structure can provide better biomechanical stability. The MSN-II may be a feasible option for the treatment of reverse obliquity inter-trochanteric fracture.
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Goossens Q, Vancleef S, Leuridan S, Pastrav LC, Mulier M, Desmet W, Vander Sloten J, Denis K. The Use of a Vibro-Acoustic Based Method to Determine the Composite Material Properties of a Replicate Clavicle Bone Model. J Funct Biomater 2020; 11:jfb11040069. [PMID: 32987709 PMCID: PMC7712050 DOI: 10.3390/jfb11040069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/11/2020] [Accepted: 09/21/2020] [Indexed: 11/16/2022] Open
Abstract
Replicate bones are widely used as an alternative for cadaveric bones for in vitro testing. These composite bone models are more easily available and show low inter-specimen variability compared to cadaveric bone models. The combination of in vitro testing with in silico models can provide further insights in the evaluation of the mechanical behavior of orthopedic implants. An accurate numerical representation of the experimental model is important to draw meaningful conclusions from the numerical predictions. This study aims to determine the elastic material constants of a commonly used composite clavicle model by combining acoustic experimental and numerical modal analysis. The difference between the experimental and finite element (FE) predicted natural frequencies was minimized by updating the elastic material constants of the transversely isotropic cortical bone analogue that are provided by the manufacturer. The longitudinal Young's modulus was reduced from 16.00 GPa to 12.88 GPa and the shear modulus was increased from 3.30 GPa to 4.53 GPa. These updated material properties resulted in an average natural frequency difference of 0.49% and a maximum difference of 1.73% between the FE predictions and the experimental results. The presented updated model aims to improve future research that focuses on mechanical simulations with clavicle composite bone models.
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Affiliation(s)
- Quentin Goossens
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
- Correspondence:
| | - Sanne Vancleef
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
| | - Steven Leuridan
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
| | - Leonard Cezar Pastrav
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
| | - Michiel Mulier
- Division of Orthopaedics, University Hospital Leuven, 3000 Leuven, Belgium;
| | - Wim Desmet
- Department of Mechanical Engineering, MSD Section, KU Leuven, 3000 Leuven, Belgium;
| | - Jos Vander Sloten
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
| | - Kathleen Denis
- Department of Mechanical Engineering, Biomechanics Section, KU Leuven, 3000 Leuven, Belgium; (S.V.); (S.L.); (L.C.P.); (J.V.S.); (K.D.)
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17
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Tatani I, Megas P, Panagopoulos A, Diamantakos I, Nanopoulos P, Pantelakis S. Comparative analysis of the biomechanical behavior of two different design metaphyseal-fitting short stems using digital image correlation. Biomed Eng Online 2020; 19:65. [PMID: 32814586 PMCID: PMC7437017 DOI: 10.1186/s12938-020-00806-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/04/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND The progressive evolution in hip replacement research is directed to follow the principles of bone and soft tissue sparing surgery. Regarding hip implants, a renewed interest has been raised towards short uncemented femoral implants. A heterogeneous group of short stems have been designed with the aim to approximate initial, post-implantation bone strain to the preoperative levels in order to minimize the effects of stress shielding. This study aims to investigate the biomechanical properties of two distinctly designed femoral implants, the TRI-LOCK Bone Preservation Stem, a shortened conventional stem and the Minima S Femoral Stem, an even shorter and anatomically shaped stem, based on experiments and numerical simulations. Furthermore, finite element models of implant-bone constructs should be evaluated for their validity against mechanical tests wherever it is possible. In this work, the validation was performed via a direct comparison of the FE calculated strain fields with their experimental equivalents obtained using the digital image correlation technique. RESULTS Design differences between Trilock BPS and Minima S femoral stems conditioned different strain pattern distributions. A distally shifting load distribution pattern as a result of implant insertion and also an obvious decrease of strain in the medial proximal aspect of the femur was noted for both stems. Strain changes induced after the implantation of the Trilock BPS stem at the lateral surface were greater compared to the non-implanted femur response, as opposed to those exhibited by the Minima S stem. Linear correlation analyses revealed a reasonable agreement between the numerical and experimental data in the majority of cases. CONCLUSION The study findings support the use of DIC technique as a preclinical evaluation tool of the biomechanical behavior induced by different implants and also identify its potential for experimental FE model validation. Furthermore, a proximal stress-shielding effect was noted after the implantation of both short-stem designs. Design-specific variations in short stems were sufficient to produce dissimilar biomechanical behaviors, although their clinical implication must be investigated through comparative clinical studies.
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Affiliation(s)
- I Tatani
- Orthopaedic Department, University Hospital of Patras, Papanikolaou 1, Rio-Patra, 26504, Patras, Greece.
| | - P Megas
- Orthopaedic Department, University Hospital of Patras, Papanikolaou 1, Rio-Patra, 26504, Patras, Greece
| | - A Panagopoulos
- Orthopaedic Department, University Hospital of Patras, Papanikolaou 1, Rio-Patra, 26504, Patras, Greece
| | - I Diamantakos
- Laboratory of Technology and Strength of Materials, Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - Ph Nanopoulos
- Department of Computer Engineering & Informatics, University of Patras, Patras, Greece
| | - Sp Pantelakis
- Laboratory of Technology and Strength of Materials, Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
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18
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Lu J, Wang QY, Sheng JG, Guo SC, Tao SC. A 3D-printed, personalized, biomechanics-specific beta-tricalcium phosphate bioceramic rod system: personalized treatment strategy for patients with femoral shaft non-union based on finite element analysis. BMC Musculoskelet Disord 2020; 21:421. [PMID: 32611412 PMCID: PMC7331224 DOI: 10.1186/s12891-020-03465-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 06/25/2020] [Indexed: 11/22/2022] Open
Abstract
Background Although double-plate fixation (DP), i.e., fixation with a combination of a main lateral plate (LP) and a support medial plate (MP), is a relatively mature method for treating femoral shaft non-union with bone defect causes complications. The purpose of this study was to evaluate LP fixation with a 3D-printed, personalized, biomechanics-specific β-TCP bioceramic rod system (LP + 3DpbsBRS) as an alternative with less collateral damage. Methods Structure-specific finite element modelling was used to simulate femoral shaft non-union with bone defects and treatment with an LP only as the blank control. Then, the peak von Mises stress (VMS), the VMS distribution, and the plate displacement were determined to compare the effectiveness of LP + CBG (cancellous bone grafting), DP + CBG, and LP + 3DpbsBRS under 850 N of axial force. Results Our results indicated that the peak VMS was 260.2 MPa (LP + 3DpbsBRS), 249.6 MPa (MP in DP + CBG), 249.3 MPa (LP in DP + CBG), and 502.4 MPa (LP + CBG). The bending angle of the plate was 1.2° versus 1.0° versus 1.1° versus 2.3° (LP + 3DpbsBRS versus MP in DP + CBG versus LP in DP + CBG versus LP + CBG). Conclusion The 3DpbsBRS in the LP + 3DpbsBRS group could replace the MP in the DP + CBG group by providing similar medial mechanical support. Furthermore, avoiding the use of an MP provides better protection of the soft tissue and vasculature.
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Affiliation(s)
- Jian Lu
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.,Department of Orthopedic Surgery, Shanghai Fengxian Central Hospital, Branch of The Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, 201400, China.,Department of Medicine, Soochou University, Suzhou, 215123, Jiangsu, China
| | - Qi-Yang Wang
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Jia-Gen Sheng
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Shang-Chun Guo
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China. .,Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.
| | - Shi-Cong Tao
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.
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19
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Lu J, Guo SC, Wang QY, Sheng JG, Tao SC. J-bone graft with double locking plate: a symphony of mechanics and biology for atrophic distal femoral non-union with bone defect. J Orthop Surg Res 2020; 15:144. [PMID: 32293488 PMCID: PMC7161247 DOI: 10.1186/s13018-020-01636-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/13/2020] [Indexed: 12/13/2022] Open
Abstract
Objective Atrophic distal femur non-union with bone defect (ADFNBD) has been a worldwide challenge to treat due to the associated biological and mechanical problems. The purpose of this study was to introduce a new solution involving the use of a J-shaped iliac crest bone graft (J-bone) combined with double-plate (DP) in the treatment of femoral non-union. Methods Clinically, 18 patients with ADFNBD were included in this retrospective study and were treated with a combination of J-bone graft and DP. The average follow-up time was 22.1 ± 5.5 months (range, 14 to 34 months). The imaging information and knee joint activity tests and scores were used to evaluate the time to weight-bearing, the time to non-union healing, and the knee joint mobility. A finite element analysis was used to evaluate the differences between the following: (1) the use of a lateral locking plate (LLP) only group (LLP-only), (2) a DP only group (DP-only), (3) a DP with a J-bone group (DP+J-bone), and (4) an LLP with a J-bone group (LLP+J-bone) in the treatment of ADFNBD. A finite element analysis ABAQUS 6.14 (Dassault systems, USA) was used to simulate the von Mises stress distribution and model displacement of the plate during standing and normal walking. Result All patients with non-union and bone defect in the distal femur achieved bone healing at an average of 22.1 ± 5.5 months (range, 14 to 34 months) postoperatively. The average healing time was 6.72 ± 2.80 months. The knee Lysholm score was significantly improved compared with that before surgery. Under both 750 N and 1800 N axial stress, the maximum stress with the DP+J-bone structure was less than that of the LLP+J-bone and DP-only structures, and the maximum stress of J-bone in the DP+J-bone was significantly less than that of the LLP+J-bone+on structure. The fracture displacement of the DP+J-bone structure was also smaller than that of the LLP+J-bone and DP-only structures. Conclusion J-bone combined with DP resulted in less maximum stress and less displacement than did a J-bone combined with an LLP or a DP-only graft for the treatment of ADFNBD. This procedure was associated with less surgical trauma, early rehabilitation exercise after surgery, a high bone healing rate, and a satisfactory rate of functional recovery. Therefore, a combination of J-bone and DP is an effective and important choice for the treatment of ADFNBD.
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Affiliation(s)
- Jian Lu
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.,The Third Affiliated Hospital of Soochow University, Changzhou, 213003, Jiangsu, China
| | - Shang-Chun Guo
- Institute of Microsurgery on Extremities, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Qi-Yang Wang
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Jia-Gen Sheng
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.
| | - Shi-Cong Tao
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China.
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20
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Li J, Wang M, Zhou J, Zhang H, Li L. Finite element analysis of different screw constructs in the treatment of unstable femoral neck fractures. Injury 2020; 51:995-1003. [PMID: 32151421 DOI: 10.1016/j.injury.2020.02.075] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/15/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVES In the present study, we evaluated the mechanical outcome of different configurations formed by partially threaded screws (PTS) alone or combined screws consisting of PTS and fully threaded screws (FTS) in the treatment of unstable femoral neck fracture. METHODS The Pauwels type III unstable femoral fracture and screw models of PTS and FTS were created in 3-matic software and UG-NX software respectively. We assembled the different screw fixation types to the fracture model separately to form the fixation models. We used Abaqus software to perform the finite element analysis. RESULTS Our results indicated that the peak von Mises stresses of screws increased when some PTSs changed into FTSs in all groups except for the inferior triangle group. FTS in each group underwent the most stress while PTS underwent a little bit of stress. The combined screws fixation types were less likely to be cut-out and was more stable than PTPs alone fixation strategy. Less yielding regions around the screw tunnels for the superior and inferior triangle configuration fixed by combined screws was indicated. Superior triangle fixation model underwent the largest area of stress concentration around the screw holes after screws removal. CONCLUSIONS For unstable femoral neck fractures, superior results were obtained by stabilizing the fracture with superior or inferior triangle configuration consisting of one PTS and two FTSs. If screws removal was taken into account after fracture union, fixation type of inferior triangle configuration should be the recommended choice.
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Affiliation(s)
- Jiantao Li
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, PR China
| | - Menglin Wang
- Department of Otolaryngology Head and Neck Surgery, Peking University Third Hospital, Beijing, 100191, PR China
| | - Jianfeng Zhou
- Department of Emergency, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, PR China
| | - Hao Zhang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, PR China.
| | - Lianting Li
- Department of Orthopaedics, The Third People's Hospital of Qingdao, No. 29 Yongping Road, Qingdao 266041, PR China.
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21
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Cordeiro M, Caskey S, Frank C, Martin S, Srivastava A, Atkinson T. Hybrid triad provides fracture plane stability in a computational model of a Pauwels Type III hip fracture. Comput Methods Biomech Biomed Engin 2020; 23:476-483. [PMID: 32160804 DOI: 10.1080/10255842.2020.1738404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The study utilized finite element method to determine displacements and stresses in a set of Pauwels Type III femoral neck fractures repaired using 3 techniques (cannulated screws (Triad), sliding hip screw (SHS), and a Hybrid (SHS + cannulated screws). The research found that shear displacement doubled between the 65° and 75° fracture angles regardless of fixation construct. The SHS alone was the least stable construct, with highest construct stresses and shear displacement along the fracture plane. The stability of the Hybrid and Triad constructs were similar, but stress in the Hybrid was lower suggesting it would provide a higher load to failure than the Triad.
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Affiliation(s)
- M Cordeiro
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA
| | - S Caskey
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA
| | - C Frank
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA
| | - S Martin
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA
| | - A Srivastava
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA
| | - T Atkinson
- Orthopaedic Surgery, McLaren-Flint, Flint, MI, USA.,Department of Mechanical Engineering, Kettering University, Flint, MI, USA
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22
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Katz Y, Yosibash Z. New insights on the proximal femur biomechanics using Digital Image Correlation. J Biomech 2020; 101:109599. [DOI: 10.1016/j.jbiomech.2020.109599] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 12/27/2019] [Accepted: 12/31/2019] [Indexed: 01/22/2023]
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Ristow J, Mead M, Cordeiro M, Ostrander J, Atkinson T, Atkinson P. Pre-bending a dynamic compression plate significantly alters strain distribution near the fracture plane in the mid-shaft femur. Proc Inst Mech Eng H 2020; 234:478-485. [PMID: 32022642 DOI: 10.1177/0954411920903875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study evaluated the effect of pre-bending dynamic compression plates on fracture site compression. Recommendations of 1 to 2 mm of pre-bend have been proposed, but there does not appear to be experimental data to confirm the optimal pre-bend magnitude. Dynamic compression plating was performed on the lateral convex surface of 18 femoral analogs to fixate a simulated mid-shaft fracture. Plates with 0 mm (flat plate), 1 mm, and 2 mm of pre-bend were evaluated for their production of compression by determining the strain magnitudes for 10 equal-sized zones across the anterior cortex at the osteotomy site using digital imaging correlation. The 0 and 1 mm plates produced significantly more compression at the near cortex (p = 0.001 and p = 0.003, respectively) than the 2 mm plate. However, the 0 and 1 mm plates also created visible diastasis at the far cortex, while the 2 mm plate exhibited compression across all zones. The strain magnitudes for the 0 mm (R2 = 0.62) and 1 mm (R2 = 0.86) plates linearly and significantly decreased from the region adjacent to the plate until a region 50%-60% across the analog diameter. In contrast, the 2 mm plate exhibited uniform strains across the osteotomy site. This study demonstrates that pre-bending a dynamic compression plate 2 mm prior to fixation on a convex lateral femur provides the most compression at the far cortex. It also produces more uniform compression across the fracture when compared to 0 and 1 mm of pre-bend.
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Affiliation(s)
- Jacob Ristow
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA
| | - Matthew Mead
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA
| | - Minal Cordeiro
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA
| | - James Ostrander
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA
| | - Theresa Atkinson
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA.,Mechanical Engineering Department, Kettering University, Flint, MI, USA
| | - Patrick Atkinson
- Department of Orthopaedic Surgery, McLaren Regional Medical Center, Flint, MI, USA.,Mechanical Engineering Department, Kettering University, Flint, MI, USA
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Experimental Validation of an ITAP Numerical Model and the Effect of Implant Stem Stiffness on Bone Strain Energy. Ann Biomed Eng 2020; 48:1382-1395. [PMID: 31974868 PMCID: PMC7089889 DOI: 10.1007/s10439-020-02456-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 01/10/2020] [Indexed: 11/27/2022]
Abstract
The Intraosseous Transcutaneous Amputation Prosthesis (ITAP) offers transfemoral amputees an ambulatory method potentially reducing soft tissue complications seen with socket and stump devices. This study validated a finite element (in silico) model based on an ITAP design and investigated implant stem stiffness influence on periprosthetic femoral bone strain. Results showed good agreement in the validation of the in silico model against the in vitro results using uniaxial strain gauges and Digital Image Correlation (DIC). Using Strain Energy Density (SED) thresholds as the stimulus for adaptive bone remodelling, the validated model illustrated that: (a) bone apposition increased and resorption decreased with increasing implant stem flexibility in early stance; (b) bone apposition decreased (mean change = − 9.8%) and resorption increased (mean change = 20.3%) from distal to proximal in most stem stiffness models in early stance. By engineering the flow of force through the implant/bone (e.g. by changing material properties) these results demonstrate how periprosthetic bone remodelling, thus aseptic loosening, can be managed. This paper finds that future implant designs should be optimised for bone strain under a variety of relevant loading conditions using finite element models to maximise the chances of clinical success.
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Abel A, Kahmann SL, Mellon S, Staat M, Jung A. An open-source tool for the validation of finite element models using three-dimensional full-field measurements. Med Eng Phys 2020; 77:125-129. [PMID: 31952915 DOI: 10.1016/j.medengphy.2019.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 07/19/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.
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Affiliation(s)
- Alexander Abel
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany
| | - Stephanie L Kahmann
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom
| | - Stephen Mellon
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom
| | - Manfred Staat
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany
| | - Alexander Jung
- Institute of Bioengineering, FH Aachen University of Applied Sciences, Heinrich-Mußmann Straße 1, 52428 Jülich, Germany; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom.
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Abstract
Meta-biomaterials are designer biomaterials with unusual and even unprecedented properties that primarily originate from their geometrical designs at different (usually smaller) length scales.
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Affiliation(s)
- Amir A. Zadpoor
- Additive Manufacturing Laboratory
- Department of Biomechanical Engineering
- Delft University of Technology (TU Delft)
- Delft 2628 CD
- The Netherlands
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Alcântara ACS, Assis I, Prada D, Mehle K, Schwan S, Costa-Paiva L, Skaf MS, Wrobel LC, Sollero P. Patient-Specific Bone Multiscale Modelling, Fracture Simulation and Risk Analysis-A Survey. MATERIALS (BASEL, SWITZERLAND) 2019; 13:E106. [PMID: 31878356 PMCID: PMC6981613 DOI: 10.3390/ma13010106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/26/2022]
Abstract
This paper provides a starting point for researchers and practitioners from biology, medicine, physics and engineering who can benefit from an up-to-date literature survey on patient-specific bone fracture modelling, simulation and risk analysis. This survey hints at a framework for devising realistic patient-specific bone fracture simulations. This paper has 18 sections: Section 1 presents the main interested parties; Section 2 explains the organzation of the text; Section 3 motivates further work on patient-specific bone fracture simulation; Section 4 motivates this survey; Section 5 concerns the collection of bibliographical references; Section 6 motivates the physico-mathematical approach to bone fracture; Section 7 presents the modelling of bone as a continuum; Section 8 categorizes the surveyed literature into a continuum mechanics framework; Section 9 concerns the computational modelling of bone geometry; Section 10 concerns the estimation of bone mechanical properties; Section 11 concerns the selection of boundary conditions representative of bone trauma; Section 12 concerns bone fracture simulation; Section 13 presents the multiscale structure of bone; Section 14 concerns the multiscale mathematical modelling of bone; Section 15 concerns the experimental validation of bone fracture simulations; Section 16 concerns bone fracture risk assessment. Lastly, glossaries for symbols, acronyms, and physico-mathematical terms are provided.
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Affiliation(s)
- Amadeus C. S. Alcântara
- Department of Computational Mechanics, School of Mechanical Engineering, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-860, Brazil; (A.C.S.A.); (D.P.)
| | - Israel Assis
- Department of Integrated Systems, School of Mechanical Engineering, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-860, Brazil;
| | - Daniel Prada
- Department of Computational Mechanics, School of Mechanical Engineering, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-860, Brazil; (A.C.S.A.); (D.P.)
| | - Konrad Mehle
- Department of Engineering and Natural Sciences, University of Applied Sciences Merseburg, 06217 Merseburg, Germany;
| | - Stefan Schwan
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, 06120 Halle/Saale, Germany;
| | - Lúcia Costa-Paiva
- Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-887, Brazil;
| | - Munir S. Skaf
- Institute of Chemistry and Center for Computing in Engineering and Sciences, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-860, Brazil;
| | - Luiz C. Wrobel
- Institute of Materials and Manufacturing, Brunel University London, Uxbridge UB8 3PH, UK;
- Department of Civil and Environmental Engineering, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro 22451-900, Brazil
| | - Paulo Sollero
- Department of Computational Mechanics, School of Mechanical Engineering, University of Campinas—UNICAMP, Campinas, Sao Paulo 13083-860, Brazil; (A.C.S.A.); (D.P.)
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Franceskides C, Leger T, Horsfall I, Tozzi G, Gibson M, Zioupos P. Evaluation of bone excision effects on a human skull model - I: Mechanical testing and digital image correlation. Proc Inst Mech Eng H 2019; 234:337-345. [PMID: 31808730 DOI: 10.1177/0954411919891885] [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: 11/17/2022]
Abstract
The mechanisms of skull impact loading may change following surgical interventions such as the removal of bone lesions, but little is known about the consequences in the event of subsequent head trauma. We, therefore, prepared acrylonitrile butadiene styrene human skull models based on clinical computed tomography skull data using a three-dimensional printer. Six replicate physical skull models were tested, three with bone excisions and three without. A drop tower was used to simulate the impact sustained by falling backwards onto the occipital lobe region. The impacts were recorded with a high-speed camera, and the occipital strain response was determined by digital image correlation. Although the hole affected neither the magnitude nor the sequence of the fracture pattern, the digital image correlation analysis highlighted an increase in strain around the excised area (0.45%-16.4% of the principal strain). Our approach provides a novel method that could improve the quality of life for patients on many fronts, including protection against trauma, surgical advice, post-operative care, advice in litigation cases, as well as facilitating general biomechanical research in the area of trauma injuries.
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Affiliation(s)
- Constantinos Franceskides
- Musculoskeletal and Medicolegal Research Group, Cranfield Forensic Institute, Cranfield University, Swindon, UK
| | - Thibault Leger
- Materials Science, University of Paris-Sud, Orsay, France
| | - Ian Horsfall
- Centre for Defence Engineering, Cranfield University, Swindon, UK
| | - Gianluca Tozzi
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, UK
| | - Michael Gibson
- Centre for Simulation and Analytics, Cranfield University, Swindon, UK
| | - Peter Zioupos
- Musculoskeletal and Medicolegal Research Group, Cranfield Forensic Institute, Cranfield University, Swindon, UK
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Panagopoulos A, Kyriakopoulos G, Anastopoulos G, Megas P, Kourkoulis SK. Design of Improved Intertrochanteric Fracture Treatment (DRIFT) Study: Protocol for Biomechanical Testing and Finite Element Analysis of Stable and Unstable Intertrochanteric Fractures Treated With Intramedullary Nailing or Dynamic Compression Screw. JMIR Res Protoc 2019; 8:e12845. [PMID: 31322133 PMCID: PMC6670281 DOI: 10.2196/12845] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 12/20/2022] Open
Abstract
Background Intertrochanteric hip fractures rank in the top 10 of all impairments worldwide in terms of loss in disability-adjusted years for people aged older than 60 years. The type of surgery is usually carried out with dynamic hip screw (DHS) devices or cephalomedullary nails (CMN). Cut-out of the hip screw is considered the most frequent mechanical failure for all implants with an estimated incidence ranging from 2% to 16.5%; this entails both enhancing our understanding of the prognostic factors of cut-out and improving all aspects of intertrochanteric fracture treatment. Objective The Design of Improved Intertrochanteric Fracture Treatment (DRIFT) study’s main objective is to provide intertrochanteric fracture treatment expertise, requirements and specifications, clinical relevance, and validation to improve treatment outcomes by developing a universal algorithm for designing patient- and fracture-oriented treatment. The hypothesis to be tested is that a more valgus reduction angle and implants of higher angles will lead to a more favorable biomechanical environment for fracture healing—that is, higher compressive loads at the fracture site with lower shear loads at the hip screw femoral head interface. A new implant with enhanced biomechanical and technical characteristics will be designed and fabricated; in addition, an integrated design and optimization platform based on computer-aided design tools and topology optimization modules will be developed. Methods To test this hypothesis, a biomechanical study comprising experimental loading of synthetic femora (Sawbones Inc) and finite element analysis (FEA) will be conducted. Detailed FEA of existing implants (DHS and CMN) implemented in different clinical cases under walking conditions will be performed to derive the stress and strain fields developed at the implant-bone system and identify critical scenarios that could lead to failure of therapy. These models would be validated against instrumented mechanical tests using strain gages and a digital image correlation process. Results After testing, geometric drawbacks of existing implants will be fully recognized, and geometric characteristics will be correlated with critical failure scenarios. The last step would be the numeric design, computer-aided design (using FEA codes and design packages), and optimization of the new proposed implant with regard to improved biomechanical surgical technique and enhanced mechanical performance that will reduce the possibility for critical failure scenarios. Conclusions The optimization of the biomechanical behavior of the fracture-osteosynthesis model by the application of the ideal reduction angle and implant is expected to have a positive effect to the rate of mechanical failure and, subsequently, the healing rates, morbidity, and mortality in this fragile patient group. International Registered Report Identifier (IRRID) DERR1-10.2196/12845
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Affiliation(s)
| | | | - Georgios Anastopoulos
- First Department of Trauma and Orthopaedics, General Hospital of Athens, Athens, Greece
| | - Panagiotis Megas
- Orthopaedic Department, Patras University Hospital, Patras-Rio, Greece
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Tatani I, Panagopoulos A, Diamantakos I, Sakellaropoulos G, Pantelakis S, Megas P. Comparison of two metaphyseal-fitting (short) femoral stems in primary total hip arthroplasty: study protocol for a prospective randomized clinical trial with additional biomechanical testing and finite element analysis. Trials 2019; 20:359. [PMID: 31208433 PMCID: PMC6580512 DOI: 10.1186/s13063-019-3445-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 05/13/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Total hip replacement has recently followed a progressive evolution towards principles of bone- and soft-tissue-sparing surgery. Regarding femoral implants, different stem designs have been developed as an alternative to conventional stems, and there is a renewed interest towards short versions of uncemented femoral implants. Based on both experimental testing and finite element modeling, the proposed study has been designed to compare the biomechanical properties and clinical performance of the newly introduced short-stem Minima S, for which clinical data are lacking with an older generation stem, the Trilock Bone Preservation Stem with an established performance record in short to midterm follow-up. METHODS/DESIGN In the experimental study, the transmission of forces as measured by cortical surface-strain distribution in the proximal femur will be evaluated using digital image correlation (DIC), first on the non-implanted femur and then on the implanted stems. Finite element parametric models of the bone, the stem and their interface will be also developed. Finite element predictions of surface strains in implanted composite femurs, after being validated against biomechanical testing measurements, will be used to assist the comparison of the stems by deriving important data on the developed stress and strain fields, which cannot be measured through biomechanical testing. Finally, a prospective randomized comparative clinical study between these two stems will be also conducted to determine (1) their clinical performance up to 2 years' follow-up using clinical scores and gait analysis (2) stem fixation and remodeling using a detailed radiographic analysis and (3) incidence and types of complications. DISCUSSION Our study would be the first that compares not only the clinical and radiological outcome but also the biomechanical properties of two differently designed femoral implants that are theoretically classified in the same main category of cervico-metaphyseal-diaphyseal short stems. We can hypothesize that even these subtle variations in geometric design between these two stems may create different loading characteristics and thus dissimilar biomechanical behaviors, which in turn could have an influence to their clinical performance. TRIAL REGISTRATION International Standard Randomized Controlled Trial Number, ID: ISRCTN10096716 . Retrospectively registered on May 8 2018.
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Affiliation(s)
- I Tatani
- Orthopaedic Department, University Hospital of Patras, Patras, Greece
| | - A Panagopoulos
- Orthopaedic Department, University Hospital of Patras, Patras, Greece.
| | - I Diamantakos
- Laboratory of Technology and Strength of Materials, Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - G Sakellaropoulos
- Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
| | - Sp Pantelakis
- Laboratory of Technology and Strength of Materials, Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - P Megas
- Orthopaedic Department, University Hospital of Patras, Patras, Greece
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Marco M, Giner E, Caeiro-Rey JR, Miguélez MH, Larraínzar-Garijo R. Numerical modelling of hip fracture patterns in human femur. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 173:67-75. [PMID: 31046997 DOI: 10.1016/j.cmpb.2019.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Hip fracture morphology is an important factor determining the ulterior surgical repair and treatment, because of the dependence of the treatment on fracture morphology. Although numerical modelling can be a valuable tool for fracture prediction, the simulation of femur fracture is not simple due to the complexity of bone architecture and the numerical techniques required for simulation of crack propagation. Numerical models assuming homogeneous fracture mechanical properties commonly fail in the prediction of fracture patterns. This paper focuses on the prediction of femur fracture based on the development of a finite element model able to simulate the generation of long crack paths. METHODS The finite element model developed in this work demonstrates the capability of predicting fracture patterns under stance loading configuration, allowing the distinction between the main fracture paths: intracapsular and extracapsular fractures. It is worth noting the prediction of different fracture patterns for the same loading conditions, as observed during experimental tests. RESULTS AND CONCLUSIONS The internal distribution of bone mineral density and femur geometry strongly influences the femur fracture morphology and fracture load. Experimental fracture paths have been analysed by means of micro-computed tomography allowing the comparison of predicted and experimental crack surfaces, confirming the good accuracy of the numerical model.
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Affiliation(s)
- Miguel Marco
- Department of Mechanical Engineering, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid, Spain.
| | - Eugenio Giner
- CIIM-Department of Mechanical and Materials Engineering, Universitat Politècnica de València Camino de Vera, 46022 Valencia, Spain
| | - José Ramón Caeiro-Rey
- Orthopedic Surgery and Traumatology Service, Complejo Hospitalario Universitario de Santiago de Compostela, Rúa de Ramón Baltar, s/n, 15706 Santiago de Compostela, A Coruña, Spain
| | - M Henar Miguélez
- Department of Mechanical Engineering, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid, Spain
| | - Ricardo Larraínzar-Garijo
- Orthopaedics and Trauma Department, Surgery Department, Hospital Universitario Infanta Leonor, Complutense University, Madrid, Spain
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Samiezadeh S, Bougherara H, Abolghasemian M, D'Lima D, Backstein D. Rotating hinge knee causes lower bone-implant interface stress compared to constrained condylar knee replacement. Knee Surg Sports Traumatol Arthrosc 2019; 27:1224-1231. [PMID: 30039293 DOI: 10.1007/s00167-018-5054-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 07/06/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE To compare the stresses at bone-arthroplasty interface of constrained and semi-constrained knee prostheses, using the finite element (FE) method as a predictor of the survivorship of the implants. METHODS Three-dimensional FE models of the knee implanted with rotating hinge (RHK) and legacy constrained condylar (LCCK) prostheses were generated to study the loads and stresses for two situations: medial- and lateral collateral ligament deficiencies in full extension. RESULTS On average, the shear stress developed at bone-implant interface dropped from 16.9 to 13.7 MPa (18.9%), and the interface von Mises stress lowered from 37.6 to 30.2 MPa (19.6%) in RHK compared to those in LCCK prostheses. RHK design also resulted in a more uniform stress distribution at the interfaces in both femur and tibia. The average polyethylene liner stress dropped from 9.6 to 2.6 MPa (a 72.7% decrease) in RHK design when compared to that in LCCK design. CONCLUSION The more uniform interface stress suggests fewer density changes at the periprosthetic regions due to bone remodelling. Moreover, the lower polyethylene stresses are likely to reduce wear and damage. These findings reveal that the RHK design may have more favorable mechanical features compared to LCCK design in full extension boundary conditions, implying a potentially better survivorship. However, the findings should be interpreted cautiously as other configurations were not investigated.
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Affiliation(s)
- Saeid Samiezadeh
- Orthopaedic Biomechanics Laboratory, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada
| | - Habiba Bougherara
- Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada
| | - Mansour Abolghasemian
- Bone and Joint Reconstruction Research Center, Shafa Hospital, Iran University of Medical Sciences, Jaleh Street, Baharestan Square, Tehran, Iran.
| | - Darryl D'Lima
- Orthopaedic Research Laboratories, Shiley Center for Orthopaedic Research and Education at Scripps Clinic, 11025 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - David Backstein
- Head of Gluskin Granovsky, Division of Orthopedic Surgery, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Toronto, ON, M5G 1X5, Canada
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Medial sustainable nail versus proximal femoral nail antirotation in treating AO/OTA 31-A2.3 fractures: Finite element analysis and biomechanical evaluation. Injury 2019; 50:648-656. [PMID: 30827705 DOI: 10.1016/j.injury.2019.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/12/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Using finite element analysis and biomechanical tests, the biomechanical behaviors of Medial Sustainable Nail (MSN) and Proximal Femoral Nail Antirotation (PFNA) were compared for the fixation of fracture type of AO/OTA 31-A2.3. METHODS Finite element software Abaqus 6.14 was used to conduct axial loading of 2100 N and we analyzed the von Mises stress distribution and the model displacement of two implant models. Biomechanical tests were separately conducted in the axial stiffness test and axial cyclical loading test on a mechanical testing machine. RESULTS The results indicate that von Mises stress of MSN was lower than that of PFNA, and the model displacement in the MSN group was lower than that in the PFNA group. In the axial stiffness tests, MSN group was stiffer than PFNA construct. With respect to the axial load to ultimate failure, the PFNA construct exhibited higher loads exceeding 4000 N while the MSN construct withstood 3313.8 ± 92.8 N. Specifically, F10mm was 2178.6 ± 133.2 N of the MSN group and 1822.6 ± 93.1 N of the PFNA group (P = 0.001). Additionally, X2100N was 9.8 ± 0.5 mm of the MSN group and 11.7 ± 0.7 mm of the PFNA group (P = 0.002). The MSN group exhibited superior performances in terms of the mean value of the vertical displacement, frontal rotation angle, and lateral rotation angle. CONCLUSIONS The results indicated that the MSN construct might exhibit a better biomechanical performance when compared with that of the PFNA in reducing displacement and anti-varus in fracture type of AO/OTA 31-A2.3.
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Abstract
Additively manufactured (AM, =3D printed) porous metallic biomaterials with topologically ordered unit cells have created a lot of excitement and are currently receiving a lot of attention given their great potential for improving bone tissue regeneration and preventing implant-associated infections.
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Affiliation(s)
- Amir A. Zadpoor
- Department of Biomechanical Engineering
- Faculty of Mechanical, Maritime, and Materials Engineering
- Delft University of Technology (TU Delft)
- Delft
- The Netherlands
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35
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Entezari A, Zhang Z, Sue A, Sun G, Huo X, Chang CC, Zhou S, Swain MV, Li Q. Nondestructive characterization of bone tissue scaffolds for clinical scenarios. J Mech Behav Biomed Mater 2019; 89:150-161. [DOI: 10.1016/j.jmbbm.2018.08.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/26/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
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Optimum Configuration of Cannulated Compression Screws for the Fixation of Unstable Femoral Neck Fractures: Finite Element Analysis Evaluation. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1271762. [PMID: 30627534 PMCID: PMC6304632 DOI: 10.1155/2018/1271762] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/16/2018] [Accepted: 11/28/2018] [Indexed: 12/17/2022]
Abstract
Objectives In the present study, we evaluated the mechanical outcome of different configurations of cannulated compression screws for the fixation of Pauwels type III femoral neck fracture and the stress distribution around the holes corresponding to fixation protocol after screws removal. Methods The Pauwels type III of femoral neck fracture was created in 3-matic software and the models of cannulated compression screws were constructed using UG-NX software. Five fixation systems were assembled to the fracture models. Abaqus software was used to perform the process of finite element analysis. Values of stress distribution, maximum stress, model principal strains of proximal fragment, and stress distribution around the holes of femur model were recorded. Results Stress of cannulated compression screws was intensely focused on the middle area of the screw near the fragment of each group. Inverted triangle model showed the highest peak stress on screws under different phases of load. Each screw dispersed some stresses, but at least one underwent the peak stress. Fracture model fixed by inverted triangle configuration showed the lowest volume of yielding strain in the proximal fragment. The area of higher stress around the holes was largest after triangle screws removal when compared with other four models. Conclusions Our study indicated that different cannulated compression screws fixation configurations for the unstable femoral neck fractures showed the different mechanical efficiency. Inverted triangular configuration showed the mechanical advantage and being less likely to cutout. The fixation strategy of triangle configuration was least recommended if patients tended to remove the implants.
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Zhang W, Li J, Zhang H, Wang M, Li L, Zhou J, Guo H, Li Y, Tang P. Biomechanical assessment of single LISS versus double-plate osteosynthesis in the AO type 33-C2 fractures: A finite element analysis. Injury 2018; 49:2142-2146. [PMID: 30322705 DOI: 10.1016/j.injury.2018.10.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 10/06/2018] [Accepted: 10/08/2018] [Indexed: 02/02/2023]
Abstract
OBJECTIVES In the present study, we assessed the biomechanical advantage between the single LISS and double-plate used in AO type 33-C2 fractures with the method of finite element analysis, which will help surgeons choose the optimal therapy to the unstable distal femoral fracture. METHODS The AO type 33-C2 fractures and the models of LISS plate and medial plate was constructed in 3-matic software and UG-NX software respectively. We then assembled the single plate and the double-plate to the fracture model separately to form the fixation models. After meshing the models' elements, we used the Abaqus software to perform the finite element analysis. Values of peak Von Mises Stress (VMS) on the plate, maximum deformation of the models and the distance changes of the fracture gap were used to capture the mechanical factors in this study. RESULTS Our results indicated that the single LISS underwent 1.2 times higher amount of stress than the double-plate (316.0 MPa VS 281.6 MPa). And the medial plate dispersed some stresses (the maximum stress is 47.4 MPa). Single-plate generated 3 times greater bending angle than double-plate (0.6° VS 0.2°). The bending angles of the single and double-fixation-fracture models are 0.9° and 0.3° respectively. The maximum distance changes of the fracture gap in the single-plate model was 2 times higher than that of double-plate model (2.6 mm VS 1.3 mm). In the torsional load analysis, peak VMS of the single and double model was 1.0 MPa and 0.8 MPa respectively. And the bending angle was 0.8° in the single model and 0.4° in the double model. CONCLUSIONS The double-plate is more effective scenario using in the distal femoral fractures, particular in unstable fractures with joint involvement.
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Affiliation(s)
- Wei Zhang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China
| | - Jiantao Li
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China
| | - Hao Zhang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China
| | - Menglin Wang
- Department of Otolaryngology Head and Neck Surgery, Peking University Third Hospital, Beijing, 100191, PR China
| | - Lianting Li
- Department of Orthopaedics, The Third People's Hospital of Qingdao, No. 29 Yongping Road, Qingdao, 266041, PR China
| | - Jianfeng Zhou
- Department of Emergency, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China
| | - Hui Guo
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China
| | - Yang Li
- Logistics University of People's Armed Police Force, Chenglin Road, Tianjin, 300162, PR China
| | - Peifu Tang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, PR China.
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Li J, Wang M, Li L, Zhang H, Hao M, Li C, Han L, Zhou J, Wang K. Finite element analysis of different configurations of fully threaded cannulated screw in the treatment of unstable femoral neck fractures. J Orthop Surg Res 2018; 13:272. [PMID: 30373617 PMCID: PMC6206921 DOI: 10.1186/s13018-018-0970-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 10/11/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the present study, we evaluated the mechanical outcome of different configurations formed by fully threaded screws and partially threaded screws in the treatment of unstable femoral neck fracture. METHODS The Pauwels type III unstable femoral fracture and the models of the fully threaded screw and partially threaded screw were constructed in 3-matic software and UG-NX software respectively. We then assembled the different screw configurations to the fracture model separately to form the fixation models. After meshing the models' elements, we used Abaqus software to perform the finite element analysis. Parameters of von Mises stress distribution on the screws, peak stress, displacement between fracture fragments, and model principal strains in cancellous bone were reported. RESULTS Our results indicated that the peak von Mises stresses of screws was concentrated in the middle surface of the screw near the fracture line in each group. Peak stress value of the implants was highest in the model of triangle with posterior single screw. And the lowest stress values were observed in the triangular model. Fully threaded screw in each group underwent the most stress while partially threaded screw underwent a little bit of stress. Lowest displacement was observed in the triangular model. The volume of bone susceptible to yielding in the femoral neck region was the lowest for triangular configuration. CONCLUSIONS For unstable femoral neck fractures, superior results were obtained by stabilizing the fracture with triangular configuration formed by one superior partially threaded screw and two inferior fully threaded screws. This study will require clinical confirmation as to its practicality in the management of unstable femoral fractures.
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Affiliation(s)
- Jiantao Li
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China
| | - Menglin Wang
- Department of Otolaryngology Head and Neck Surgery, Peking University Third Hospital, Beijing, 100191, People's Republic of China
| | - Lianting Li
- Department of Orthopaedics, The Third People's Hospital of Qingdao, No. 29 Yongping Road, Qingdao, 266041, People's Republic of China
| | - Hao Zhang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China
| | - Ming Hao
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China
| | - Chen Li
- Department of Orthopaedics, Tianjin Hospital, NO. 406 Jiefang Road, Tianjin, 300211, People's Republic of China
| | - Lin Han
- Graduate School of the Second Military Medical University, Shanghai, 200433, China
| | - Jianfeng Zhou
- Department of Emergency, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
| | - Kun Wang
- Department of Orthopaedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
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Finite Element Analysis of Different Double-Plate Angles in the Treatment of the Femoral Shaft Nonunion with No Cortical Support opposite the Primary Lateral Plate. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3267107. [PMID: 30151378 PMCID: PMC6091371 DOI: 10.1155/2018/3267107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/09/2018] [Accepted: 07/09/2018] [Indexed: 01/14/2023]
Abstract
Objectives We evaluated the biomechanical outcome of different plate fixation strategies (the single plate construct, 45° double-plate construct, 90° double-plate construct, 135° double-plate construct, and 180° double-plate construct) used for the fixation of the femoral shaft nonunion with no cortical support opposite the primary lateral plate. This may help surgeons choose the optimal therapy to the femoral shaft nonunion. Methods The femoral shaft nonunion with no medial support and the models of lateral plate and medial plate was constructed in 3-matic software and UG-NX software, respectively. We then assembled the single plate and different double plates to the fracture model separately to form the fixation models. After meshing the models' elements, we used the ABAQUS software to perform the finite element analysis. Values of the von Mises Stress (VMS) distribution of the implant, peak VMS, and model displacement and deformation were used to capture the mechanical factors in this study. Results Our results indicated that the peak von Mises Stress (VMS) of the lateral plate was concentrated in middle surface of the lateral plate near the fragment of each group. The peak VMS was 5201.0 MPa (the single-plate construct), 3490.0 MPa (45° double-plate construct), 1754.0 MPa (90° double-plate construct), 1123.0 MPa (135° double-plate construct), and 816.5 MPa (180° double-plate construct). The additional short plate dispersed some stress leading to the decrease in the peak VMS of the lateral plate. As angle formed by the double plates increased, the dispersed function of the additional plate was becoming obvious. The bending angles of the lateral plate were 18° versus 12° versus 3° versus 2° versus 1° (the single-plate construct versus 45° double-plate construct versus 90° double-plate construct versus 135° double-plate construct versus 180° double-plate construct). Conclusions Our study indicated that increasing the angle between the plates in a double-plate construct improves the stability of the construct over a single lateral plate when there is no cortical support opposite to the lateral plate. The strongest fixation occurred when the angle between the two plates was greater than ninety degrees.
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Ochoa-Cabrero R, Alonso-Rasgado T, Davey K. Scaling in biomechanical experimentation: a finite similitude approach. J R Soc Interface 2018; 15:rsif.2018.0254. [PMID: 29899162 DOI: 10.1098/rsif.2018.0254] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 05/18/2018] [Indexed: 11/12/2022] Open
Abstract
Biological experimentation has many obstacles: resource limitations, unavailability of materials, manufacturing complexities and ethical compliance issues; any approach that resolves all or some of these is of some interest. The aim of this study is applying the recently discovered concept of finite similitude as a novel approach for the design of scaled biomechanical experiments supported with analysis using a commercial finite-element package and validated by means of image correlation software. The study of isotropic scaling of synthetic bones leads to the selection of three-dimensional (3D) printed materials for the trial-space materials. These materials conforming to the theory are analysed in finite-element models of a cylinder and femur geometries undergoing compression, tension, torsion and bending tests to assess the efficacy of the approach using reverse scaling of the approach. The finite-element results show similar strain patterns in the surface for the cylinder with a maximum difference of less than 10% and for the femur with a maximum difference of less than 4% across all tests. Finally, the trial-space, physical-trial experimentation using 3D printed materials for compression and bending testing provides a good agreement in a Bland-Altman statistical analysis, providing good supporting evidence for the practicality of the approach.
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Affiliation(s)
- Raul Ochoa-Cabrero
- School of Materials Science, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK
| | - Teresa Alonso-Rasgado
- School of Materials Science, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK
| | - Keith Davey
- School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK
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Enns-Bray W, Bahaloo H, Fleps I, Ariza O, Gilchrist S, Widmer R, Guy P, Pálsson H, Ferguson S, Cripton P, Helgason B. Material mapping strategy to improve the predicted response of the proximal femur to a sideways fall impact. J Mech Behav Biomed Mater 2018; 78:196-205. [DOI: 10.1016/j.jmbbm.2017.10.033] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/25/2017] [Accepted: 10/26/2017] [Indexed: 11/29/2022]
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Jetté B, Brailovski V, Dumas M, Simoneau C, Terriault P. Femoral stem incorporating a diamond cubic lattice structure: Design, manufacture and testing. J Mech Behav Biomed Mater 2018; 77:58-72. [DOI: 10.1016/j.jmbbm.2017.08.034] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/13/2017] [Accepted: 08/28/2017] [Indexed: 10/19/2022]
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MacLeod AR, Rose H, Gill HS. A Validated Open-Source Multisolver Fourth-Generation Composite Femur Model. J Biomech Eng 2017; 138:2552969. [PMID: 27618586 DOI: 10.1115/1.4034653] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Indexed: 11/08/2022]
Abstract
Synthetic biomechanical test specimens are frequently used for preclinical evaluation of implant performance, often in combination with numerical modeling, such as finite-element (FE) analysis. Commercial and freely available FE packages are widely used with three FE packages in particular gaining popularity: abaqus (Dassault Systèmes, Johnston, RI), ansys (ANSYS, Inc., Canonsburg, PA), and febio (University of Utah, Salt Lake City, UT). To the best of our knowledge, no study has yet made a comparison of these three commonly used solvers. Additionally, despite the femur being the most extensively studied bone in the body, no freely available validated model exists. The primary aim of the study was primarily to conduct a comparison of mesh convergence and strain prediction between the three solvers (abaqus, ansys, and febio) and to provide validated open-source models of a fourth-generation composite femur for use with all the three FE packages. Second, we evaluated the geometric variability around the femoral neck region of the composite femurs. Experimental testing was conducted using fourth-generation Sawbones® composite femurs instrumented with strain gauges at four locations. A generic FE model and four specimen-specific FE models were created from CT scans. The study found that the three solvers produced excellent agreement, with strain predictions being within an average of 3.0% for all the solvers (r2 > 0.99) and 1.4% for the two commercial codes. The average of the root mean squared error against the experimental results was 134.5% (r2 = 0.29) for the generic model and 13.8% (r2 = 0.96) for the specimen-specific models. It was found that composite femurs had variations in cortical thickness around the neck of the femur of up to 48.4%. For the first time, an experimentally validated, finite-element model of the femur is presented for use in three solvers. This model is freely available online along with all the supporting validation data.
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Affiliation(s)
- Alisdair R MacLeod
- Centre for Biomechanics, Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK e-mail:
| | - Hannah Rose
- Centre for Biomechanics, Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK e-mail:
| | - Harinderjit S Gill
- Centre for Biomechanics, Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK e-mail:
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Leuridan S, Goossens Q, Vander Sloten T, De Landsheer K, Delport H, Pastrav L, Denis K, Desmet W, Vander Sloten J. Vibration-based fixation assessment of tibial knee implants: A combined in vitro and in silico feasibility study. Med Eng Phys 2017; 49:109-120. [DOI: 10.1016/j.medengphy.2017.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 07/07/2017] [Accepted: 08/13/2017] [Indexed: 10/18/2022]
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Development and in vitro validation of a simplified numerical model for the design of a biomimetic femoral stem. J Mech Behav Biomed Mater 2017; 77:539-550. [PMID: 29069636 DOI: 10.1016/j.jmbbm.2017.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/06/2017] [Accepted: 10/15/2017] [Indexed: 11/21/2022]
Abstract
BACKGROUND Dense and stiff metallic femoral stems implanted into femurs for total hip arthroplasties produce a stress shielding effect since they modify the original load sharing path in the bony structure. Consequently, in the long term, the strain adaptive nature of bones leads to bone resorption, implant loosening, and the need for arthroplasty revision. The design of new cementless femoral stems integrating open porous structures can reduce the global stiffness of the stems, allowing them a better match with that of bones and provide their firm fixation via bone ingrowth, and, thus reduce the risk of implantation failure. METHODS This paper aims to develop and validate a simplified numerical model of stress shielding, which calculates the levels of bone resorption or formation by comparing strain distributions on the surface of the intact and the implanted femurs subjected to a simulated biological loading. Two femoral stems produced by laser powder-bed fusion using Ti-6Al-4V alloy are employed: the first is fully dense, while the second features a diamond cubic lattice structure in its core. The validation consists of a comparison of the numerically calculated force-displacement diagrams, and displacement and strain fields with their experimental equivalents obtained using the digital image correlation technique. RESULTS AND CONCLUSIONS The numerical models showed reasonable agreement between the force-displacement diagrams. Also, satisfactory results for the correlation analyses of the total displacement and equivalent strain fields were obtained. The stress shielding effect of the implant was assessed by comparing the equivalent strain fields of the implanted and intact femurs. The results obtained predicted less bone resorption in the femur implanted with the porous stem than with its dense counterpart.
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Lopes VM, Neto MA, Amaro AM, Roseiro LM, Paulino M. FE and experimental study on how the cortex material properties of synthetic femurs affect strain levels. Med Eng Phys 2017. [DOI: 10.1016/j.medengphy.2017.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Bettamer A, Allaoui S, Hambli R. Using 3D digital image correlation to visualise the progress of failure of human proximal femur. COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING: IMAGING & VISUALIZATION 2017. [DOI: 10.1080/21681163.2015.1067152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Messias A, Neto MA, Amaro AM, Nicolau P, Roseiro LM. Effect of round curvature of anterior implant-supported zirconia frameworks: finite element analysis and in vitro study using digital image correlation. Comput Methods Biomech Biomed Engin 2017; 20:1236-1248. [DOI: 10.1080/10255842.2017.1348501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ana Messias
- Department of Dentistry, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CEMMPRE, Center for Mechanical Engineering, Materials and Process, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Maria Augusta Neto
- CEMMPRE, Center for Mechanical Engineering, Materials and Process, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Ana Martins Amaro
- CEMMPRE, Center for Mechanical Engineering, Materials and Process, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Pedro Nicolau
- Department of Dentistry, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- CEMMPRE, Center for Mechanical Engineering, Materials and Process, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
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Marco M, Giner E, Larraínzar-Garijo R, Caeiro JR, Miguélez MH. Numerical Modelling of Femur Fracture and Experimental Validation Using Bone Simulant. Ann Biomed Eng 2017. [DOI: 10.1007/s10439-017-1877-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Zhang XY, Fang G, Zhou J. Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review. MATERIALS 2017; 10:ma10010050. [PMID: 28772411 PMCID: PMC5344607 DOI: 10.3390/ma10010050] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 12/15/2022]
Abstract
Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors’ view on the current challenges and further research directions.
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Affiliation(s)
- Xiang-Yu Zhang
- Department of Mechanical Engineering, Tsinghua University, Beijing 10004, China.
| | - Gang Fang
- Department of Mechanical Engineering, Tsinghua University, Beijing 10004, China.
- State Key Laboratory of Tribology, Beijing 100084, China.
| | - Jie Zhou
- Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
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