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Nan C, Liu Y, Zhang D, Qin Y, Yu H, Ma Z. Biomechanical changes in the proximal femur before and after removal of femoral neck system. J Orthop Surg Res 2024; 19:290. [PMID: 38735949 PMCID: PMC11089723 DOI: 10.1186/s13018-024-04769-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 05/01/2024] [Indexed: 05/14/2024] Open
Abstract
BACKGROUND As an innovative internal fixation system, FNS (femoral neck system) is increasingly being utilized by surgeons for the treatment of femoral neck fractures. At present, there have been numerous finite element analysis experiments studying the immediate stability of FNS and CSS in treating femoral neck fractures. However, there is scarce mechanical analysis available regarding the effects post internal fixation removal. This study aimed to investigate the alterations in mechanical parameters of the proximal femur before and after the removal of FNS (femoral neck system), and to assess potential distinctions in indicators following the extraction of CSS (Cannulated Screws). METHODS A proximal femur model was reconstructed using finite element numerical techniques. The models for CSS and FNS were formulated utilizing characteristics and parametric definitions. The internal fixation was combined with a normal proximal femur model to simulate the healing state after fracture surgery. Within the framework of static analysis, consistent stress burdens were applied across the entirety of the models. The total deformation and equivalent stress of the proximal femur were recorded before and after the removal of internal fixation. RESULTS Under the standing condition, the total deformation of the model before and after removing CSS was 0.99 mm and 1.10 mm, respectively, indicating an increase of 12%. The total deformation of the model before and after removing FNS was 0.65 mm and 0.76 mm, respectively, indicating an increase of 17%. The equivalent stress for CSS and FNS were 55.21 MPa and 250.67 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of CSS was 7.76 MPa and 6.11 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of FNS was 9.89 MPa and 8.79 MPa, respectively. CONCLUSIONS The retention of internal fixation may contribute to improved stability of the proximal femur. However, there still existed risks of stress concentration in internal fixation and stress shielding in the proximal femur. Compared to CSS, the removal of FNS results in larger bone tunnels and insufficient model stability. Further clinical interventions are recommended to address this issue.
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Affiliation(s)
- Chong Nan
- Department of Orthopedic, Baoding No. 1 Central Hospital, Baoding, Hebei Province, 071000, China
| | - Yuxiu Liu
- Department of Orthopedic, Baoding No. 1 Central Hospital, Baoding, Hebei Province, 071000, China
| | - Di Zhang
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, 050000, China
| | - Yazhuo Qin
- Department of Orthopedic, Baoding No. 1 Central Hospital, Baoding, Hebei Province, 071000, China
| | - Hetong Yu
- Department of Orthopedic, Baoding No. 1 Central Hospital, Baoding, Hebei Province, 071000, China
| | - Zhanbei Ma
- Department of Orthopedic, Baoding No. 1 Central Hospital, Baoding, Hebei Province, 071000, China.
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Hindurao B, Gujare A, Jadhav H, Dhatrak P. Evaluate the effect of bone density variation on stress distribution at the bone-implant interface using numerical analysis. Proc Inst Mech Eng H 2024; 238:463-470. [PMID: 38534009 DOI: 10.1177/09544119241240940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The current study aims to comprehend how different bone densities affect stress distribution at the bone-implant interface. This will help understand the behaviour and help predict success rates of the implant planted in different bone densities. The process of implantation involves the removal of bone from a small portion of the jawbone to replace either a lost tooth or an infected one and an implant is inserted in the cavity made as a result. Now the extent of fixation due to osseointegration is largely dependent on the condition of the bone in terms of the density. Generally, the density of the bone is classified into four categories namely D1, D2, D3, and D4; with D1 being purely cortical and D4 having higher percentage of cancellous bordered by cortical bone. A bone model with a form closely resembling the actual bone was made using 3D CAD software and was meshed using Hyper Mesh. The model was subjected to an oblique load of 120 N at 70° to the vertical to replicate occlusal loading. A finite element static analysis was done using Abaqus software. The stress distribution contours at the bone-implant contact zone were studied closely to understand the changes as a result of the varying density. It was revealed that as the quantity of the cancellous bone increased from D1 to D4 the cortical peak stress levels dropped. The bone density and the corresponding change in the material characteristics was also responsible for the variation in the peak stress and displacement values.
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Affiliation(s)
- Bhargav Hindurao
- Department of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune, Maharashtra, India
| | - Aditya Gujare
- Department of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune, Maharashtra, India
| | - Harshavardhan Jadhav
- Department of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune, Maharashtra, India
| | - Pankaj Dhatrak
- Department of Mechanical Engineering, Dr Vishwanath Karad MIT World Peace University, Pune, Maharashtra, India
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3
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Yang J, Pei Q, Wu X, Dai X, Li X, Pan J, Wang B. Stress reduction through cortical bone thickening improves bone mechanical behavior in adult female Beclin-1 +/- mice. Front Bioeng Biotechnol 2024; 12:1357686. [PMID: 38600946 PMCID: PMC11004267 DOI: 10.3389/fbioe.2024.1357686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/13/2024] [Indexed: 04/12/2024] Open
Abstract
Fragility fractures, which are more prevalent in women, may be significantly influenced by autophagy due to altered bone turnover. As an essential mediator of autophagy, Beclin-1 modulates bone homeostasis by regulating osteoclast and chondrocyte differentiation, however, the alteration in the local bone mechanical environment in female Beclin-1+/- mice remains unclear. In this study, our aim is to investigate the biomechanical behavior of femurs from seven-month-old female wild-type (WT) and Beclin-1+/- mice under peak physiological load, using finite element analysis on micro-CT images. Micro-CT imaging analyses revealed femoral cortical thickening in Beclin-1+/- female mice compared to WT. Three-point bending test demonstrated a 63.94% increase in whole-bone strength and a 61.18% increase in stiffness for female Beclin-1+/- murine femurs, indicating improved biomechanical integrity. After conducting finite element analysis, Beclin-1+/- mice exhibited a 26.99% reduction in von Mises stress and a 31.62% reduction in maximum principal strain in the femoral midshaft, as well as a 36.64% decrease of von Mises stress in the distal femurs, compared to WT mice. Subsequently, the strength-safety factor was determined using an empirical formula, revealing that Beclin-1+/- mice exhibited significantly higher minimum safety factors in both the midshaft and distal regions compared to WT mice. In summary, considering the increased response of bone adaptation to mechanical loading in female Beclin-1+/- mice, our findings indicate that increasing cortical bone thickness significantly improves bone biomechanical behavior by effectively reducing stress and strain within the femoral shaft.
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Affiliation(s)
- Jiaojiao Yang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Qilin Pei
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Xingfan Wu
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Xin Dai
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Xi Li
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Jun Pan
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Bin Wang
- Institute of Life Sciences, College of Basic Medicine, Chongqing Medical University, Chongqing, China
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4
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Kim J, Chun BJ, Kim JJ. Quantitative Load Dependency Analysis of Local Trabecular Bone Microstructure to Understand the Spatial Characteristics in the Synthetic Proximal Femur. BIOLOGY 2023; 12:biology12020170. [PMID: 36829449 PMCID: PMC9953259 DOI: 10.3390/biology12020170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023]
Abstract
Analysis of the dependency of the trabecular structure on loading conditions is essential for understanding and predicting bone structure formation. Although previous studies have investigated the relationship between loads and structural adaptations, there is a need for an in-depth analysis of this relationship based on the bone region and load specifics. In this study, the load dependency of the trabecular bone microstructure for twelve regions of interest (ROIs) in the synthetic proximal femur was quantitatively analyzed to understand the spatial characteristics under seven different loading conditions. To investigate the load dependency, a quantitative measure, called the load dependency score (LDS), was established based on the statistics of the strain energy density (SED) distribution. The results showed that for the global model and epiphysis ROIs, bone microstructures relied on the multiple-loading condition, whereas the structures in the metaphysis depended on single or double loads. These results demonstrate that a given ROI is predominantly dependent on a particular loading condition. The results confirm that the dependency analysis of the load effects for ROIs should be performed both qualitatively and quantitatively.
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Affiliation(s)
- Jisun Kim
- Department of Mechanical Engineering, Keimyung University, Daegu 42601, Republic of Korea
| | - Bong Ju Chun
- Cho Chun Shik Graduate School of Mobility, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34051, Republic of Korea
| | - Jung Jin Kim
- Department of Mechanical Engineering, Keimyung University, Daegu 42601, Republic of Korea
- Correspondence: ; Tel.: +82-53-580-5290; Fax: +82-53-715-2029
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Cronin DS, Watson B, Khor F, Gierczycka D, Malcolm S. Cortical bone continuum damage mechanics constitutive model with stress triaxiality criterion to predict fracture initiation and pattern. Front Bioeng Biotechnol 2022; 10:1022506. [PMID: 36324891 PMCID: PMC9618659 DOI: 10.3389/fbioe.2022.1022506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/26/2022] [Indexed: 01/22/2023] Open
Abstract
A primary objective of finite element human body models (HBMs) is to predict response and injury risk in impact scenarios, including cortical bone fracture initiation, fracture pattern, and the potential to simulate post-fracture injury to underlying soft tissues. Current HBMs have been challenged to predict the onset of failure and bone fracture patterns owing to the use of simplified failure criteria. In the present study, a continuum damage mechanics (CDM) model, incorporating observed mechanical response (orthotropy, asymmetry, damage), was coupled to a novel phenomenological effective strain fracture criterion based on stress triaxiality and investigated to predict cortical bone response under different modes of loading. Three loading cases were assessed: a coupon level notched shear test, whole bone femur three-point bending, and whole bone femur axial torsion. The proposed material model and fracture criterion were able to predict both the fracture initiation and location, and the fracture pattern for whole bone and specimen level tests, within the variability of the reported experiments. There was a dependence of fracture threshold on finite element mesh size, where higher mesh density produced similar but more refined fracture patterns compared to coarser meshes. Importantly, the model was functional, accurate, and numerically stable even for relatively coarse mesh sizes used in contemporary HBMs. The proposed model and novel fracture criterion enable prediction of fracture initiation and resulting fracture pattern in cortical bone such that post-fracture response can be investigated in HBMs.
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Affiliation(s)
- D. S Cronin
- Department of MME, University of Waterloo, Waterloo, ON, Canada
- *Correspondence: D. S Cronin,
| | - B Watson
- Department of MME, University of Waterloo, Waterloo, ON, Canada
| | - F Khor
- Department of MME, University of Waterloo, Waterloo, ON, Canada
| | - D Gierczycka
- Department of MME, University of Waterloo, Waterloo, ON, Canada
| | - S Malcolm
- Honda Development and Manufacturing of America, Raymond, OH, United States
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Prada DM, Galvis AF, Miller J, Foster JM, Zavaglia C. Multiscale stiffness characterisation of both healthy and osteoporotic bone tissue using subject-specific data. J Mech Behav Biomed Mater 2022; 135:105431. [DOI: 10.1016/j.jmbbm.2022.105431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 08/22/2022] [Accepted: 08/26/2022] [Indexed: 10/31/2022]
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Mathai B, Dhara S, Gupta S. Bone remodelling in implanted proximal femur using topology optimization and parameterized cellular model. J Mech Behav Biomed Mater 2021; 125:104903. [PMID: 34717117 DOI: 10.1016/j.jmbbm.2021.104903] [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: 02/28/2021] [Revised: 09/09/2021] [Accepted: 10/12/2021] [Indexed: 10/20/2022]
Abstract
The clinical relevance of bone remodelling predictions calls for accurate finite element (FE) modelling of implant-bone structure and musculoskeletal loading conditions. However, simplifications in muscle loading, material properties, has often been used in FE simulations. Bone adaptation induces changes in bone apparent density and its microstructure. Multiscale simulations, involving optimization methods and biomimetic microstructural models, have proven to be promising for predicting changes in bone morphology. The objective of the study is to develop a novel computational framework to predict bone remodelling around an uncemented femoral implant, using multiscale topology optimization and a parameterized cellular model. The efficacy of the scheme was evaluated by comparing the remodelling predictions with those of isotropic strain energy density (SED) and orthotropy based formulations. The characteristic functional groups and low-density regions of Ward's triangle, predicted by the optimization scheme, were comparable to micro-CT images of the proximal femur. Although the optimization scheme predicted well comparable material distribution in the 2D femur models, the obscured material orientations in some planes of the 3D model indicate the need for a more robust modelling of the boundary conditions. Regression analysis revealed a higher correlation (0.6472) between the topology optimization and SED models than the orthotropic predictions (0.4219). Despite higher bone apposition of 10-20% around the distal tip of the implant, the bone density distributions were well comparable to clinical observations towards the proximal femur. The proposed computational scheme appears to be a viable method for including bone anisotropy in the remodelling formulation.
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Affiliation(s)
- Basil Mathai
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India
| | - Santanu Dhara
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India
| | - Sanjay Gupta
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India.
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8
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Pisano AA, Fuschi P. Limit analysis of human proximal femur. J Mech Behav Biomed Mater 2021; 124:104844. [PMID: 34601433 DOI: 10.1016/j.jmbbm.2021.104844] [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: 03/16/2021] [Revised: 09/03/2021] [Accepted: 09/15/2021] [Indexed: 10/20/2022]
Abstract
A limit analysis numerical approach oriented to predict the peak/collapse load of human proximal femur, under two different loading conditions, is presented. A yield criterion of Tsai-Hu-type, expressed in principal stress space, is used to model the orthotropic bone tissues. A simplified human femur 3D model is envisaged to carry on numerical simulation of in-vitro tests borrowed from the relevant literature and to reproduce their findings. A critical discussion, together with possible future developments, is presented.
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Affiliation(s)
- A A Pisano
- University Mediterranea of Reggio Calabria, Via dell'Universitá 25, I-89124 Reggio Calabria, Italy.
| | - P Fuschi
- University Mediterranea of Reggio Calabria, Via dell'Universitá 25, I-89124 Reggio Calabria, Italy
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Subchondral Bone Relative Area and Density in Human Osteoarthritic Femoral Heads Assessed with Micro-CT before and after Mechanical Embedding of the Innovative Multi-Spiked Connecting Scaffold for Resurfacing THA Endoprostheses: A Pilot Study. J Clin Med 2021; 10:jcm10132937. [PMID: 34208953 PMCID: PMC8268800 DOI: 10.3390/jcm10132937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 12/19/2022] Open
Abstract
The multi-spiked connecting scaffold (MSC-Scaffold) prototype is the essential innovation in the fixation of components of resurfacing total hip arthroplasty (THRA) endoprostheses in the subchondral trabecular bone. We conducted the computed micro-tomography (micro-CT) assessment of the subchondral trabecular bone microarchitecture before and after the MSC-Scaffold embedding in femoral heads removed during long-stem endoprosthesis total hip arthroplasty (THA) of different bone densities from 4 patients with hip osteoarthritis (OA). The embedding of the MSC-Scaffold in subchondral trabecular bone causes the change in its relative area (BA/TA, bone area/total area ratio) ranged from 18.2% to 24.7% (translating to the calculated density ρB relative change 11.1–14.4%, and the compressive strength S relative change 75.3–122.7%) regardless of its initial density (before the MSC-Scaffold embedding). The densification of the trabecular microarchitecture of subchondral trabecular bone due to the MSC-Scaffold initial embedding gradually decreases with the increasing distance from the apexes of the MSC-Scaffold’s spikes while the spatial extent of this subchondral trabecular bone densification ranged from 1.5 to 2.5 mm (which is about half the height of the MSC-Scaffold’s spikes). It may be suggested, despite the limited number of examined femoral heads, that: (1) the magnitude of the effect of the MSC-Scaffold embedding on subchondral trabecular bone densification may be a factor contributing to the maintenance of the MSC-Scaffold also for decreased initial bone density values, (2) the deeper this effect of the subchondral trabecular bone densification, the better strength of subchondral trabecular bone, and as consequence, the better post-operative embedding of the MSC-Scaffold in the bone should be expected.
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Mathai B, Dhara S, Gupta S. Orthotropic bone remodelling around uncemented femoral implant: a comparison with isotropic formulation. Biomech Model Mechanobiol 2021; 20:1115-1134. [PMID: 33768358 DOI: 10.1007/s10237-021-01436-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 02/11/2021] [Indexed: 11/25/2022]
Abstract
Peri-prosthetic bone adaptation has usually been predicted using subject-specific finite element analysis in combination with remodelling algorithms and assuming isotropic bone material property. The objective of the study is to develop an orthotropic bone remodelling algorithm for evaluation of peri-prosthetic bone adaptation in the uncemented implanted femur. The simulations considered loading conditions from a variety of daily activities. The orthotropic algorithm was tested on 2D and 3D models of the intact femur for verification of predicted results. The predicted orthotropic directionality, based on principal stress directions, was in agreement with the trabecular orientation in a micro-CT data of proximal femur. The validity of the proposed strain-based algorithm was assessed by comparing the predicted results of the orthotropic model with those of the strain-energy-density-based isotropic formulation. Despite agreement in cortical densities [Formula: see text], the isotropic remodelling algorithm tends to predict relatively higher values around the distal tip of the implant as compared to the orthotropic model. Both formulations predicted 4-8% bone resorption in the proximal femur. A linear regression analysis revealed a significant correlation [Formula: see text] between the stresses and strains on the cortex of the proximal femur, predicted by the isotropic and orthotropic formulations. Despite reasonable agreement in peri-prosthetic bone density distributions, the quantitative differences with isotropic model predictions highlight the combined influences of bone orthotropy and mechanical stimulus in the adaptation process.
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Affiliation(s)
- Basil Mathai
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721 302, India
| | - Santanu Dhara
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721 302, India
| | - Sanjay Gupta
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721 302, India.
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Li JJ, Tian DM, Yang L, Zhang JY, Hu YC. Influence of a metaphyseal sleeve on the stress-strain state of a bone-tumor implant system in the distal femur: an experimental and finite element analysis. J Orthop Surg Res 2020; 15:589. [PMID: 33298115 PMCID: PMC7724731 DOI: 10.1186/s13018-020-02025-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 10/14/2020] [Indexed: 12/03/2022] Open
Abstract
Background Aseptic loosening of distal femoral tumor implants significantly correlates with the resection length. We designed a new “sleeve” that is specially engaged in the metaphysis at least 5 cm proximal to the knee joint line to preserve as much bone stock as possible. This study investigates the influence of a metaphyseal sleeve on the stress-strain state of a bone tumor implant system in the distal femur. Methods Cortex strains in intact and implanted femurs were predicted with finite element (FE) models. Moreover strains were experimentally measured in a cadaveric femur with and without a sleeve and stem under an axial compressive load of 1000 N. The FE models, which were validated by linear regression, were used to investigate the maximal von Mises stress and the implanted-to-intact (ITI) ratios of strain in the femur with single-legged stance loading under immediate postoperative and osseointegration conditions. Results Good agreement was noted between the experimental measurements and numerical predictions of the femoral strains (coefficient of determination (R2) ≥ 0.95; root-mean-square error (RMSE%) ≈ 10%). The ITI ratios for the metaphysis were between 13 and 28% and between 10 and 21% under the immediate postoperative and osseointegration conditions, respectively, while the ITI ratios for the posterior and lateral cortices around the tip of the stem were 110% and 119% under the immediate-postoperative condition, respectively, and 114% and 101% under the osseointegration condition, respectively. The maximal von Mises stresses for the implanted femur were 113.8 MPa and 43.41 MPa under the immediate postoperative and osseointegration conditions, which were 284% and 47% higher than those in the intact femur (29.6 MPa), respectively. Conclusions This study reveals that a metaphyseal sleeve may cause stress shielding relative to the intact femur, especially in the distal metaphysis. Stress concentrations might mainly occur in the posterior cortex around the tip of the stem. However, stress concentrations may not be accompanied by periprosthetic fracture under the single-legged stance condition.
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Affiliation(s)
- Jian-Jun Li
- Tianjin Medical University, 22 Qixiangtai Road, Tianjin, People's Republic of China.,Department of Bone Oncology, Tianjin Hospital, 406 Jiefang Southern Road, Tianjin, People's Republic of China.,Department of Bone Trauma, Second Hospital of Tangshan, 22 Jianshe North Road, Tangshan, Hebei, People's Republic of China
| | - Dong-Mu Tian
- Beijing Weigao Yahua Artificial Joint Development Company, 7 Niuhui Street, Shunyi, Beijing, People's Republic of China
| | - Li Yang
- Tianjin Medical University, 22 Qixiangtai Road, Tianjin, People's Republic of China
| | - Jing-Yu Zhang
- Department of Bone Oncology, Second Hospital of Tangshan, 22 Jianshe North Road, Tangshan, Hebei, People's Republic of China
| | - Yong-Cheng Hu
- Department of Bone Oncology, Tianjin Hospital, 406 Jiefang Southern Road, Tianjin, People's Republic of China.
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12
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Toniolo I, Salmaso C, Bruno G, De Stefani A, Stefanini C, Gracco ALT, Carniel EL. Anisotropic computational modelling of bony structures from CT data: An almost automatic procedure. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 189:105319. [PMID: 31951872 DOI: 10.1016/j.cmpb.2020.105319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/27/2019] [Accepted: 01/05/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVE The use of modelling techniques that combine CT data and bone tissue micromechanics is spreading in computational biomechanics. Finite Element models show great potential in surgical planning of intervention and in prediction of stress and strain fields through a non-invasive method. The main challenge pertains to the reliable characterization of bone mechanical behaviour. An almost automatic procedure is here defined, which provides computational models of bony structures considering the actual anisotropy of bone tissue response. The innovative aspect resides on the automatic detection of the directions of anisotropy as the eigenvectors of a three-dimensional distribution matrix of HU values. METHODS The procedure combines CT data and micromechanics modelling techniques. Regarding a specific location, the procedure reports both the orthotropic elastic constants, by the analysis of the local HU value, and the anisotropic material directions, by the analysis of the HU values distribution around the specific location. RESULTS The procedure returns the distribution of bone tissue orthotropic elasticity tensor. The procedure proves to correctly respect the differentiation between cortical and trabecular bone. Principal directions show to be consistent with experimental data from ultrasound measurements. Regarding the material mapping from voxel to FE model, the developed strategies show to be reliable, leading to marginal errors (lower than 10%) for most of CT voxels (more than 90%). The computational analyses of typical structural loading conditions lead to strain values that are comparable with results from strain gauges experimentations. The development and the exploitation of FE models of different bony structures allow assessing the reliability of the procedure for cortical bone. CONCLUSIONS The results highlight the potentialities of the procedure in providing accurate patient-specific biomechanical models of bony structures starting from CT data. The accuracy and the automatism of the procedure are important factors for the development of real time clinical tools. The main limitations of this work remain the not fully automatism and the reliability assessment, which is based mainly on cortical bone regions only.
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Affiliation(s)
- Ilaria Toniolo
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy; Department of Industrial Engineering, University of Padova, Italy.
| | - Claudia Salmaso
- Department of Industrial Engineering, University of Padova, Italy
| | - Giovanni Bruno
- Department of Neurosciences, University of Padova, Italy
| | | | - Cesare Stefanini
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Emanuele Luigi Carniel
- Department of Industrial Engineering, University of Padova, Italy; Centre for Mechanics of Biological Materials, University of Padova, Italy
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Xie P, Deng Y, Tan J, Wang M, Yang Y, Ouyang H, Huang W. The effect of rotational degree and routine activity on the risk of collapse in transtrochanteric rotational osteotomy for osteonecrosis of the femoral head-a finite element analysis. Med Biol Eng Comput 2020; 58:805-814. [PMID: 32016806 PMCID: PMC7156356 DOI: 10.1007/s11517-020-02137-5] [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: 04/13/2019] [Accepted: 01/22/2020] [Indexed: 11/24/2022]
Abstract
To explore the mechanical mechanism and provide preoperative planning basis for transtrochanteric rotational osteotomy (TRO) procedure, a joint-preserving procedure for osteonecrosis of the femoral head. Eleven TRO finite element femurs with the most common types of necrosis were analyzed under multi-loading conditions. Thereafter, we made a comprehensive evaluation by considering the anatomy characters, daily activities, and risk indicators contain necrosis expansion trend, necrotic blood supply pressure, and the risk of fracture. The risk of fracture (ROF) is the lowest when standing on feet and increases gradually during normal walking and walking upstairs and downstairs. Compared with posterior rotation, rotating forward keeps more elements at low risk. Additionally, the correlation analysis shows it has a strong negative correlation (R2 = 0.834) with the average modulus of the roof. TRO finally decreased the stress and energy effectively. However, the stress and strain energy arise when rotated posteriorly less than 120°. The comprehensive evaluation observed that rotating forward 90°could reduce the total risks to 64%. TRO is an effective technique to prevent collapse. For the anterior and superior large necrosis, we recommend to rotate forward 60° to 90° (more efficient) or backward 180°. The methodology followed in this study could provide accurate and personalize preoperative planning. A proximal femur was reconstructed and modified using Mimics from a series of computed tomography. The models were meshed after solidified and performed different osteotomy, and then assigned material based on the Hounsfield Unit from CT images. Finally, 44 different TRO finite element femurs were analyzed under multi-loading conditions and evaluated comprehensively. ![]()
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Affiliation(s)
- Pusheng Xie
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China.,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China.,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China
| | - Yuping Deng
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China.,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China.,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China
| | - Jinchuan Tan
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China.,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China.,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China
| | - Mian Wang
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China.,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China.,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China
| | - Yang Yang
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China.,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China.,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China
| | - Hanbin Ouyang
- Orthopaedic Center, Affiliated Hospital of Guangdong Medical University, Guangdong Medical University, Zhanjiang, 524002, People's Republic of China.
| | - Wenhua Huang
- National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China. .,Department of Anatomy, School of Basic Medicine Science, Guangdong Provincial Key laboratory of Medical Biomechanics, Southern Medical University, 1023 ShaTai Rd, Baiyun District, Guangzhou, 510515, People's Republic of China. .,Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, Southern Medical University, 1023 ShaTai Rd, Guangzhou, 510515, People's Republic of China. .,Orthopaedic Center, Affiliated Hospital of Guangdong Medical University, Guangdong Medical University, Zhanjiang, 524002, People's Republic of China.
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14
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Dhatrak P, Girme V, Shirsat U, Sumanth S, Deshmukh V. Significance of Orthotropic Material Models to Predict Stress Around Bone-Implant Interface Using Numerical Simulation. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00649-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Chethan K, Zuber M, Bhat SN, Shenoy SB. Comparative Study of Femur Bone Having Different Boundary Conditions and Bone Structure Using Finite Element Method. Open Biomed Eng J 2018. [DOI: 10.2174/1874120701812010115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background:Femur bone is an important part in human which basically gives stability and support to carry out all day to day activities. It carries loads from upper body to lower abdomen.Objective:In this work, the femur having composite structure with cortical, cancellous and bone marrow cavity is bisected from condyle region with respect to 25%, 50% and 75% of its height. There is considerable difference in the region chosen for fixing all degrees of freedom in the analysis of femur.Methods:The CT scans are taken, and 3D model is developed using MIMICS. The developed model is used for static structural analysis by varying the load from 500N to 3000N.Results:The findings for 25% bisected femur model report difference in directional deformation less than 5% for loads 2000N and less. In the study comparing fully solid bone and the composite bone, the total deformation obtained for a complete solid bone was 3.5 mm which was 18.7% less than that determined for the composite bone.Conclusion:The standardization for fixing the bone is developed. And it is required to fix the distal end always with considering full femur bone.
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16
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Taghizadeh E, Chandran V, Reyes M, Zysset P, Büchler P. Statistical analysis of the inter-individual variations of the bone shape, volume fraction and fabric and their correlations in the proximal femur. Bone 2017; 103:252-261. [PMID: 28732775 DOI: 10.1016/j.bone.2017.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/22/2017] [Accepted: 07/11/2017] [Indexed: 10/19/2022]
Abstract
Including structural information of trabecular bone improves the prediction of bone strength and fracture risk. However, this information is available in clinical CT scans, only for peripheral bones. We hypothesized that a correlation exists between the shape of the bone, its volume fraction (BV/TV) and fabric, which could be characterized using statistical modeling. High-resolution peripheral computed tomography (HR-pQCT) images of 73 proximal femurs were used to build a combined statistical model of shape, BV/TV and fabric. The model was based on correspondence established by image registration and by morphing of a finite element mesh describing the spatial distribution of the bone properties. Results showed no correlation between the distribution of bone shape, BV/TV and fabric. Only the first mode of variation associated with density and orientation showed a strong relationship (R2>0.8). In addition, the model showed that the anisotropic information of the proximal femur does not vary significantly in a population of healthy, osteoporotic and osteopenic samples. In our dataset, the average anisotropy of the population was able to provide a close approximation of the patient-specific anisotropy. These results were confirmed by homogenized finite element (hFE) analyses, which showed that the biomechanical behavior of the proximal femur was not significantly different when the average anisotropic information of the population was used instead of patient-specific fabric extracted from HR-pQCT. Based on these findings, it can be assumed that the fabric information of the proximal femur follows a similar structure in an elderly population of healthy, osteopenic and osteoporotic proximal femurs.
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Affiliation(s)
- Elham Taghizadeh
- Institute for Surgical Technology and Biomechanics (ISTB), University of Bern, Switzerland
| | - Vimal Chandran
- Institute for Surgical Technology and Biomechanics (ISTB), University of Bern, Switzerland
| | - Mauricio Reyes
- Institute for Surgical Technology and Biomechanics (ISTB), University of Bern, Switzerland
| | - Philippe Zysset
- Institute for Surgical Technology and Biomechanics (ISTB), University of Bern, Switzerland
| | - Philippe Büchler
- Institute for Surgical Technology and Biomechanics (ISTB), University of Bern, Switzerland.
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17
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Nazemi SM, Kalajahi SMH, Cooper DML, Kontulainen SA, Holdsworth DW, Masri BA, Wilson DR, Johnston JD. Accounting for spatial variation of trabecular anisotropy with subject-specific finite element modeling moderately improves predictions of local subchondral bone stiffness at the proximal tibia. J Biomech 2017; 59:101-108. [PMID: 28601243 DOI: 10.1016/j.jbiomech.2017.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 04/20/2017] [Accepted: 05/23/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Previously, a finite element (FE) model of the proximal tibia was developed and validated against experimentally measured local subchondral stiffness. This model indicated modest predictions of stiffness (R2=0.77, normalized root mean squared error (RMSE%)=16.6%). Trabecular bone though was modeled with isotropic material properties despite its orthotropic anisotropy. The objective of this study was to identify the anisotropic FE modeling approach which best predicted (with largest explained variance and least amount of error) local subchondral bone stiffness at the proximal tibia. METHODS Local stiffness was measured at the subchondral surface of 13 medial/lateral tibial compartments using in situ macro indentation testing. An FE model of each specimen was generated assuming uniform anisotropy with 14 different combinations of cortical- and tibial-specific density-modulus relationships taken from the literature. Two FE models of each specimen were also generated which accounted for the spatial variation of trabecular bone anisotropy directly from clinical CT images using grey-level structure tensor and Cowin's fabric-elasticity equations. Stiffness was calculated using FE and compared to measured stiffness in terms of R2 and RMSE%. RESULTS The uniform anisotropic FE model explained 53-74% of the measured stiffness variance, with RMSE% ranging from 12.4 to 245.3%. The models which accounted for spatial variation of trabecular bone anisotropy predicted 76-79% of the variance in stiffness with RMSE% being 11.2-11.5%. CONCLUSIONS Of the 16 evaluated finite element models in this study, the combination of Synder and Schneider (for cortical bone) and Cowin's fabric-elasticity equations (for trabecular bone) best predicted local subchondral bone stiffness.
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Affiliation(s)
- S Majid Nazemi
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.
| | | | - David M L Cooper
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Canada
| | | | | | - Bassam A Masri
- Department of Orthopedics and Centre for Hip Health and Mobility, University of British Columbia, Vancouver, BC, Canada
| | - David R Wilson
- Department of Orthopedics and Centre for Hip Health and Mobility, University of British Columbia, Vancouver, BC, Canada
| | - James D Johnston
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.
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18
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Morphology based anisotropic finite element models of the proximal femur validated with experimental data. Med Eng Phys 2016; 38:1339-1347. [DOI: 10.1016/j.medengphy.2016.08.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 08/05/2016] [Accepted: 08/30/2016] [Indexed: 11/21/2022]
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19
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Mechanobiological simulations of peri-acetabular bone ingrowth: a comparative analysis of cell-phenotype specific and phenomenological algorithms. Med Biol Eng Comput 2016; 55:449-465. [DOI: 10.1007/s11517-016-1528-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
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20
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Taghizadeh E, Reyes M, Zysset P, Latypova A, Terrier A, Büchler P. Biomechanical Role of Bone Anisotropy Estimated on Clinical CT Scans by Image Registration. Ann Biomed Eng 2016; 44:2505-2517. [PMID: 26790866 DOI: 10.1007/s10439-016-1551-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 01/13/2016] [Indexed: 11/27/2022]
Abstract
Image-based modeling is a popular approach to perform patient-specific biomechanical simulations. Accurate modeling is critical for orthopedic application to evaluate implant design and surgical planning. It has been shown that bone strength can be estimated from the bone mineral density (BMD) and trabecular bone architecture. However, these findings cannot be directly and fully transferred to patient-specific modeling since only BMD can be derived from clinical CT. Therefore, the objective of this study was to propose a method to predict the trabecular bone structure using a µCT atlas and an image registration technique. The approach has been evaluated on femurs and patellae under physiological loading. The displacement and ultimate force for femurs loaded in stance position were predicted with an error of 2.5% and 3.7%, respectively, while predictions obtained with an isotropic material resulted in errors of 7.3% and 6.9%. Similar results were obtained for the patella, where the strain predicted using the registration approach resulted in an improved mean squared error compared to the isotropic model. We conclude that the registration of anisotropic information from of a single template bone enables more accurate patient-specific simulations from clinical image datasets than isotropic model.
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Affiliation(s)
- Elham Taghizadeh
- Institute for Surgical Technology & Biomechanics, University of Bern, Stauffacherstrasse 78, 3014, Bern, Switzerland
| | - Mauricio Reyes
- Institute for Surgical Technology & Biomechanics, University of Bern, Stauffacherstrasse 78, 3014, Bern, Switzerland
| | - Philippe Zysset
- Institute for Surgical Technology & Biomechanics, University of Bern, Stauffacherstrasse 78, 3014, Bern, Switzerland
| | - Adeliya Latypova
- Laboratory of Biomechanical Orthopedics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alexandre Terrier
- Laboratory of Biomechanical Orthopedics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Philippe Büchler
- Institute for Surgical Technology & Biomechanics, University of Bern, Stauffacherstrasse 78, 3014, Bern, Switzerland.
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21
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The influence of bone density and anisotropy in finite element models of distal radius fracture osteosynthesis: Evaluations and comparison to experiments. J Biomech 2015; 48:4116-4123. [PMID: 26542787 DOI: 10.1016/j.jbiomech.2015.10.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 10/07/2015] [Accepted: 10/10/2015] [Indexed: 11/23/2022]
Abstract
Continuum-level finite element (FE) models can be used to analyze and improve osteosynthesis procedures for distal radius fractures (DRF) from a biomechanical point of view. However, previous models oversimplified the bone material and lacked thorough experimental validation. The goal of this study was to assess the influence of local bone density and anisotropy in FE models of DRF osteosynthesis for predictions of axial stiffness, implant plate stresses, and screw loads. Experiments and FE analysis were conducted in 25 fresh frozen cadaveric radii with DRFs treated by volar locking plate osteosynthesis. Specimen specific geometries were captured using clinical quantitative CT (QCT) scans of the prepared samples. Local bone material properties were computed based on high resolution CT (HR-pQCT) scans of the intact radii. The axial stiffness and individual screw loads were evaluated in FE models, with (1) orthotropic inhomogeneous (OrthoInhom), (2) isotropic inhomogeneous (IsoInhom), and (3) isotropic homogeneous (IsoHom) bone material and compared to the experimental axial stiffness and screw-plate interface failures. FE simulated and experimental axial stiffness correlated significantly (p<0.0001) for all three model types. The coefficient of determination was similar for OrthoInhom (R(2)=0.807) and IsoInhom (R(2)=0.816) models but considerably lower for IsoHom models (R(2)=0.500). The peak screw loads were in qualitative agreement with experimental screw-plate interface failure. Individual loads and implant plate stresses of IsoHom models differed significantly (p<0.05) from OrthoInhom and IsoInhom models. In conclusion, including local bone density in FE models of DRF osteosynthesis is essential whereas local bone anisotropy hardly effects the models׳ predictive abilities.
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Enns-Bray WS, Owoc JS, Nishiyama KK, Boyd SK. Mapping anisotropy of the proximal femur for enhanced image based finite element analysis. J Biomech 2014; 47:3272-8. [DOI: 10.1016/j.jbiomech.2014.08.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 08/07/2014] [Accepted: 08/18/2014] [Indexed: 11/28/2022]
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23
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Grassi L, Väänänen SP, Amin Yavari S, Jurvelin JS, Weinans H, Ristinmaa M, Zadpoor AA, Isaksson H. Full-Field Strain Measurement During Mechanical Testing of the Human Femur at Physiologically Relevant Strain Rates. J Biomech Eng 2014; 136:1901145. [DOI: 10.1115/1.4028415] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 08/27/2014] [Indexed: 11/08/2022]
Abstract
Understanding the mechanical properties of human femora is of great importance for the development of a reliable fracture criterion aimed at assessing fracture risk. Earlier ex vivo studies have been conducted by measuring strains on a limited set of locations using strain gauges (SGs). Digital image correlation (DIC) could instead be used to reconstruct the full-field strain pattern over the surface of the femur. The objective of this study was to measure the full-field strain response of cadaver femora tested at a physiological strain rate up to fracture in a configuration resembling single stance. The three cadaver femora were cleaned from soft tissues, and a white background paint was applied with a random black speckle pattern over the anterior surface. The mechanical tests were conducted up to fracture at a constant displacement rate of 15 mm/s, and two cameras recorded the event at 3000 frames per second. DIC was performed to retrieve the full-field displacement map, from which strains were derived. A low-pass filter was applied over the measured displacements before the crack opened in order to reduce the noise level. The noise levels were assessed using a dedicated control plate. Conversely, no filtering was applied at the frames close to fracture to get the maximum resolution. The specimens showed a linear behavior of the principal strains with respect to the applied force up to fracture. The strain rate was comparable to the values available in literature from in vivo measurements during daily activities. The cracks opened and fully propagated in less than 1 ms, and small regions with high values of the major principal strains could be spotted just a few frames before the crack opened. This corroborates the hypothesis of a strain-driven fracture mechanism in human bone. The data represent a comprehensive collection of full-field strains, both at physiological load levels and up to fracture. About 10,000 points were tracked on each bone, providing superior spatial resolution compared to ∼15 measurements typically collected using SGs. These experimental data collection can be further used for validation of numerical models, and for experimental verification of bone constitutive laws and fracture criteria.
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Affiliation(s)
- Lorenzo Grassi
- Division of Solid Mechanics, Lund University, Lund 22363, Sweden
- Department of Biomedical Engineering, Lund University, BMC D13, Sölvegatan 19, Lund 22184, Sweden e-mail:
| | - Sami P. Väänänen
- Department of Applied Physics, University of Eastern Finland, Kuopio 70211, Finland
| | - Saber Amin Yavari
- Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
| | - Jukka S. Jurvelin
- Department of Applied Physics, University of Eastern Finland, Kuopio 70211, Finland
| | - Harrie Weinans
- Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
- Department of Orthopaedics, UMC Utrecht 3508 GA, The Netherlands
| | - Matti Ristinmaa
- Division of Solid Mechanics, Lund University, Lund 22363, Sweden
| | - Amir A. Zadpoor
- Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
| | - Hanna Isaksson
- Division of Solid Mechanics, Lund University, Lund 22363, Sweden
- Department of Biomedical Engineering, Lund University, Lund 22184, Sweden
- Department of Orthopaedics, Lund University, Lund 22184, Sweden
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Hambli R. 3D finite element simulation of human proximal femoral fracture under quasi-static load. ACTA ACUST UNITED AC 2014. [DOI: 10.12989/aba.2013.1.1.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Effect of boundary conditions, impact loading and hydraulic stiffening on femoral fracture strength. J Biomech 2013; 46:2115-21. [DOI: 10.1016/j.jbiomech.2013.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 06/29/2013] [Accepted: 07/05/2013] [Indexed: 11/20/2022]
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26
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Kersh ME, Zysset PK, Pahr DH, Wolfram U, Larsson D, Pandy MG. Measurement of structural anisotropy in femoral trabecular bone using clinical-resolution CT images. J Biomech 2013; 46:2659-66. [PMID: 24007613 DOI: 10.1016/j.jbiomech.2013.07.047] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/30/2013] [Accepted: 07/31/2013] [Indexed: 11/28/2022]
Abstract
Discrepancies in finite-element model predictions of bone strength may be attributed to the simplified modeling of bone as an isotropic structure due to the resolution limitations of clinical-level Computed Tomography (CT) data. The aim of this study is to calculate the preferential orientations of bone (the principal directions) and the extent to which bone is deposited more in one direction compared to another (degree of anisotropy). Using 100 femoral trabecular samples, the principal directions and degree of anisotropy were calculated with a Gradient Structure Tensor (GST) and a Sobel Structure Tensor (SST) using clinical-level CT. The results were compared against those calculated with the gold standard Mean-Intercept-Length (MIL) fabric tensor using micro-CT. There was no significant difference between the GST and SST in the calculation of the main principal direction (median error=28°), and the error was inversely correlated to the degree of transverse isotropy (r=-0.34, p<0.01). The degree of anisotropy measured using the structure tensors was weakly correlated with the MIL-based measurements (r=0.2, p<0.001). Combining the principal directions with the degree of anisotropy resulted in a significant increase in the correlation of the tensor distributions (r=0.79, p<0.001). Both structure tensors were robust against simulated noise, kernel sizes, and bone volume fraction. We recommend the use of the GST because of its computational efficiency and ease of implementation. This methodology has the promise to predict the structural anisotropy of bone in areas with a high degree of anisotropy, and may improve the in vivo characterization of bone.
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Affiliation(s)
- Mariana E Kersh
- Department of Mechanical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia.
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27
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A Robust 3D Finite Element Simulation of Human Proximal Femur Progressive Fracture Under Stance Load with Experimental Validation. Ann Biomed Eng 2013; 41:2515-27. [DOI: 10.1007/s10439-013-0864-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/06/2013] [Indexed: 01/22/2023]
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28
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A quasi-brittle continuum damage finite element model of the human proximal femur based on element deletion. Med Biol Eng Comput 2012. [DOI: 10.1007/s11517-012-0986-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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