1
|
Akbas O, Greuling A, Stiesch M. The effects of different grading approaches in additively manufactured dental implants on peri-implant bone stress: A finite element analysis. J Mech Behav Biomed Mater 2024; 154:106530. [PMID: 38552334 DOI: 10.1016/j.jmbbm.2024.106530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024]
Abstract
Additive manufacturing enables local grading of the stiffness of dental implants through targeted adjustment of the manufacturing parameters to meet patient specific requirements. The extent to which such a manufacturing approach affects the interaction between the implant body and the surrounding bone, and what grading is optimal, is currently insufficiently investigated. This study investigates the effect of different Young's modulus grading approaches on stresses in the peri-implant bone via finite element analysis. The implant geometry was kept constant and in the case of the implant a node-dependent elastic modulus was assigned. In this way, a vertical, a radial and three torus based grading approaches were created and examined. A load was then applied directly to the occlusal surface of the implant crown. It was found that a local grading utilizing a torus shape was most favourable in terms of an effective stress peak reduction. The best torus shape tested achieved a 22 % reduction of maximum principal stress and 6 % reduction of minimum principal stress compared to the uniform material. In clinical settings, this may provide benefits in situations of overload. Based on the results, a graded stiffness in dental implants appears to be of interest for developing advanced, patient-specific implant solutions.
Collapse
Affiliation(s)
- Osman Akbas
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Hannover, Germany
| | - Andreas Greuling
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Hannover, Germany.
| | - Meike Stiesch
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Hannover, Germany
| |
Collapse
|
2
|
Chancharoen W, Pansai J, Boonchuay T, Saeya S, Das R, Chobpenthai T, Aimmanee S. Performance parametric formulation of carbon fiber-reinforced composite locking bone implant plates based on finite-element analysis. Comput Methods Biomech Biomed Engin 2024:1-17. [PMID: 38808689 DOI: 10.1080/10255842.2024.2358362] [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: 03/10/2024] [Accepted: 05/17/2024] [Indexed: 05/30/2024]
Abstract
The treatment of Giant Cell Tumor (GCT) in the distal radius poses challenges due to the intricate anatomical features of the bone. It often necessitates the use of long implant plates or the interconnection of multiple short plates after tumor excision. However, the deployment of metal plates may increase the risk of screw loosening and various complications. To address these challenges, this study proposes the adoption of carbon fiber-reinforced PEEK (CFRP) as the base material. As a unique strategy, performance parameters (PP) were developed to compare CFRP implant plates with a Ti-6Al-4V plate using the Finite-element Method. The focus was on four elements: the screw axial force, bone growth, callus formation, and bone resorption. The investigation into the screw axial force involved analyzing the internal force of the screw. The remaining parameters were evaluated using the stress, strain, or elastic energy induced in the bones. The findings showed that the second screw endured the largest screw axial force, measuring 10.16 N under a 90-degree 10-N loading at the translocated bone. The model without a callus exerted a significantly greater force on the screw than the model with a callus, leading to screw loosening in the early stage of treatment. The maximum PP, reached 1.62, was achieved with an angle-ply [456/-456] laminate, featuring a weighting fraction of 0.7 for bone growth and 0.1 for the other parameters. This study provides a generalized methodology for assessing the performances of CFRP implants and offers guidelines for future development in composite implant plate technology.
Collapse
Affiliation(s)
- Wares Chancharoen
- Laboratory of Artificial Intelligence and Innovation in Medicine (AIIM), Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, LakSi, Thailand
| | - Jirapong Pansai
- Advanced Materials and Structures Laboratory (AMASS), Center for Lightweight Materials Design and Manufacturing, Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Thung Khru, Thailand
| | - Teeravut Boonchuay
- Advanced Materials and Structures Laboratory (AMASS), Center for Lightweight Materials Design and Manufacturing, Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Thung Khru, Thailand
| | - Somchart Saeya
- Advanced Materials and Structures Laboratory (AMASS), Center for Lightweight Materials Design and Manufacturing, Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Thung Khru, Thailand
| | - Raj Das
- School of Engineering, RMIT University, Melbourne, Australia
| | - Thanapon Chobpenthai
- Laboratory of Artificial Intelligence and Innovation in Medicine (AIIM), Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, LakSi, Thailand
| | - Sontipee Aimmanee
- Advanced Materials and Structures Laboratory (AMASS), Center for Lightweight Materials Design and Manufacturing, Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Thung Khru, Thailand
| |
Collapse
|
3
|
Rajaeirad M, Fakharifar A, Posti MHZ, Khorsandi M, Watts DC, Elraggal A, Ouldyerou A, Merdji A, Roy S. Evaluating the effect of functionally graded materials on bone remodeling around dental implants. Dent Mater 2024; 40:858-868. [PMID: 38616152 DOI: 10.1016/j.dental.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/27/2024] [Accepted: 04/02/2024] [Indexed: 04/16/2024]
Abstract
OBJECTIVES This study evaluates the potential for osseointegration and remodeling of customized dental implants made from Titanium-Hydroxyapatite Functionally Graded Material (Ti-HAP FGM) with optimized geometry, using the finite element method (FEM). METHODS The study utilized CT scan images to model and assemble various geometrical designs of dental implants in a mandibular slice. The mechanical properties of Ti-HAP FGMs were computed by varying volume fractions (VF) of hydroxyapatite (0-20%), and a bone remodeling algorithm was used to evaluate the biomechanical characteristics of the ultimate bone configuration in the peri-implant tissue. RESULTS The findings of the FEA reveal that osseointegration improves with changes in the density and mechanical properties of the bone surrounding Ti-HAP implants, which are influenced by the varying VF of hydroxyapatite in the FGM. SIGNIFICANCE Increasing the hydroxyapatite fraction improves osseointegration, and appropriate length and diameter selection of Ti-HAP dental implants contribute to their stability and longevity.
Collapse
Affiliation(s)
- Mohadese Rajaeirad
- Department of Biomedical Engineering, University of Isfahan, Isfahan, Iran
| | - Ashkan Fakharifar
- Faculty of Medicine, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran
| | | | | | - David C Watts
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Alaaeldin Elraggal
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Egypt
| | - Abdelhak Ouldyerou
- Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Algeria
| | - Ali Merdji
- Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Algeria
| | - Sandipan Roy
- Department of Mechanical Engineering, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, India.
| |
Collapse
|
4
|
Fouquet V, Larsen N, Stchepinsky AC, Vennat E, Benoit A, Tapie L. A parametrical finite element analysis for functionally graded material overlay restoration. J Mech Behav Biomed Mater 2024; 152:106409. [PMID: 38277910 DOI: 10.1016/j.jmbbm.2024.106409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/13/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
The main cause of failure in bonded ceramic restorations is material fracture due to excessive stress concentration at the base of the prosthesis. The design of restorative functionally graded materials (FGM) could represent a major advance in dissipating mechanical stresses during occlusal contacts. The aim of this paper is to carry out a complete factorial design of finite element analyses to optimize a multilayer FGM introduced at the bottom of an overlay prosthesis. The number and thickness of layers vary within a spectrum compatible with ceramic shaping processes whereas Young's moduli variations are set in the range of dental tissues. For a 1.5-mm thick prosthesis, the optimal FGM configuration appears to be a 5 layers of 0.2 mm thickness with a linear distribution of Young's modulus from 30 to 70 GPa. This configuration was implemented in a 3D model of a restored tooth with realistic geometry to validate the proof-of-concept.
Collapse
Affiliation(s)
- Vincent Fouquet
- Université Paris Cité, Université Sorbonne Paris Nord, URB2i, F-92120, Montrouge, France; Université Sorbonne Paris Nord, F-93430, Villetaneuse, France; AP-HP, Louis-Mourier Hospital, Oral Medecine Department, F-92700, Colombes, France
| | - Nicoline Larsen
- Université Paris Cité, Université Sorbonne Paris Nord, URB2i, F-92120, Montrouge, France
| | | | - Elsa Vennat
- Université Paris Cité, Université Sorbonne Paris Nord, URB2i, F-92120, Montrouge, France; Université Paris-Saclay, CentraleSupélec, ENS Paris-Saclay, CNRS, LMPS - Laboratoire de Mécanique Paris-Saclay, 91190, Gif sur Yvette, France
| | - Aurélie Benoit
- Université Paris Cité, Université Sorbonne Paris Nord, URB2i, F-92120, Montrouge, France.
| | - Laurent Tapie
- Université Paris Cité, Université Sorbonne Paris Nord, URB2i, F-92120, Montrouge, France; EPF Engineering School, F-94230, Cachan, France.
| |
Collapse
|
5
|
Młynarek-Żak K, Żmudzki J. The effect of porous compliance bushings in a dental implant on the distribution of occlusal loads. Sci Rep 2024; 14:1607. [PMID: 38238380 PMCID: PMC10796672 DOI: 10.1038/s41598-024-51429-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 04/02/2023] [Indexed: 01/22/2024] Open
Abstract
Porous dental implants are clinically used, but the mechanism of load distribution for stepped implant shaft surrounded by compliance bushings is still not known, especially for different bone conditions. The aim of the study was to assess the impact of the design of a dental implant with compliance bushings (CBs) on the occlusal load distribution during primary and secondary stability using finite element simulation (FEA), with a distinction between low and high quality cervical support under primary stability. The FEA of the oblique occlusal load transfer (250 N; 45°) was carried out for implants under variable bone conditions. The stepped shaft in the intermediate part of the dental implant was surrounded by CBs with an increasing modulus of elasticity of 2, 10 and 50 GPa. With a smaller Young's modulus of the bushings the increase of stress in the trabecular bone indicated that more bone tissue can be protected against disuse. The beneficial effect for the trabecular bone derived from the reduction of the stiffness of the bushings in relation to the loss of the implant's load bearing ability can be assessed using the FEM method.
Collapse
Affiliation(s)
- Katarzyna Młynarek-Żak
- Department of Engineering Processes Automation and Integrated Manufacturing Systems, Silesian University of Technology, Konarskiego 18a St., 44-100, Gliwice, Poland
| | - Jarosław Żmudzki
- Department of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego 18a St., 44-100, Gliwice, Poland.
| |
Collapse
|
6
|
Zhai Y, Zhang H, Liu T, Zou C, Zhou C. Mechanical property of Ti6Al4V cylindrical porous structure for dental implants fabricated by selective laser melting. Comput Methods Biomech Biomed Engin 2024:1-19. [PMID: 38178700 DOI: 10.1080/10255842.2023.2300686] [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: 07/28/2023] [Accepted: 12/03/2023] [Indexed: 01/06/2024]
Abstract
The commonly used titanium alloy dental implants currently apply solid structures. However, issues such as stress shielding and stress concentration may arise due to the significant difference in elastic modulus between the implant and host. In order to address these problems, this paper proposes five porous structures based on the Gibson-Ashby theoretical model. We utilized selective laser melting technology to shape a porous structure using Ti-6Al-4V material precisely. The mechanical properties of the porous structure were verified through simulation and compression experiments. The optimal porous structure, which best matched the human bone, was a circular ring structure with a pillar diameter of 0.6 mm and a layer height of 2 mm. The stress and strain of the porous implant on the surrounding cortical and cancellous bone under different biting conditions were studied to verify the effectiveness of the optimal circular ring porous structure in alleviating stress shielding in both standard and osteoporotic bone conditions. The results confirm that the circular ring porous structure meets implant requirements and provides a theoretical basis for clinical dental implantation.
Collapse
Affiliation(s)
- Yun Zhai
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Hao Zhang
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Tong Liu
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Cong Zou
- Department of Stomatology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Changchun Zhou
- National Engineering Research Centre for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu, China
| |
Collapse
|
7
|
Thomková B, Marcián P, Borák L, Joukal M, Wolff J. Biomechanical performance of dental implants inserted in different mandible locations and at different angles: A finite element study. J Prosthet Dent 2024; 131:128.e1-128.e10. [PMID: 37919129 DOI: 10.1016/j.prosdent.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 11/04/2023]
Abstract
STATEMENT OF PROBLEM Accurate implant placement is essential for the success of dental implants. This placement influences osseointegration and occlusal forces. The freehand technique, despite its cost-effectiveness and time efficiency, may result in significant angular deviations compared with guided implantation, but the effect of angular deviations on the stress-strain state of peri-implant bone is unclear. PURPOSE The purpose of this finite element analysis (FEA) study was to examine the effects of angular deviations on stress-strain states in peri-implant bone. MATERIAL AND METHODS Computational modeling was used to investigate 4 different configurations of dental implant positions, each with 3 angles of insertion. The model was developed using computed tomography images, and typical mastication forces were considered. Strains were analyzed using the mechanostat hypothesis. RESULTS The location of the implant had a significant impact on bone strain intensity. An angular deviation of ±5 degrees from the planned inclination did not significantly affect cancellous bone strains, which primarily support the implant. However, it had a substantial effect on strains in the cortical bone near the implant. Such deviations also significantly influenced implant stresses, especially when the support from the cortical bone was uneven or poorly localized. CONCLUSIONS In extreme situations, angular deviations can lead to overstraining the cortical bone, risking implant failure from unfavorable interaction with the implant. Accurate implant placement is essential to mitigate these risks.
Collapse
Affiliation(s)
- Barbora Thomková
- Graduate student, Institute of Solid Mechanics, Mechatronics and Biomechanics, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Petr Marcián
- Graduate student, Institute of Solid Mechanics, Mechatronics and Biomechanics, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic.
| | - Libor Borák
- Graduate student, Institute of Solid Mechanics, Mechatronics and Biomechanics, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Marek Joukal
- Associate Professor, Department of Anatomy, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jan Wolff
- Professor, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| |
Collapse
|
8
|
Ouldyerou A, Mehboob H, Mehboob A, Merdji A, Aminallah L, Mukdadi OM, Barsoum I, Junaedi H. Biomechanical performance of resin composite on dental tissue restoration: A finite element analysis. PLoS One 2023; 18:e0295582. [PMID: 38128035 PMCID: PMC10734934 DOI: 10.1371/journal.pone.0295582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/23/2023] [Indexed: 12/23/2023] Open
Abstract
This study investigates the biomechanical performance of various dental materials when filled in different cavity designs and their effects on surrounding dental tissues. Finite element models of three infected teeth with different cavity designs, Class I (occlusal), Class II mesial-occlusal (MO), and Class II mesio-occluso-distal (MOD) were constructed. These cavities were filled with amalgam, composites (Young's moduli of 10, 14, 18, 22, and 26 GPa), and glass carbomer cement (GCC). An occlusal load of 600 N was distributed on the top surface of the teeth to carry out simulations. The findings revealed that von Mises stress was higher in GCC material, with cavity Class I (46.01 MPa in the enamel, 23.61 MPa in the dentin), and for cavity Class II MO von Mises stress was 43.64 MPa, 39.18 MPa in enamel and dentin respectively, while in case of cavity Class II MOD von Mises stress was 44.67 MPa in enamel, 27.5 in the dentin. The results showed that higher stresses were generated in the non-restored tooth compared to the restored one, and increasing Young's modulus of restorative composite material decreases stresses in enamel and dentin. The use of composite material showed excellent performance which can be a good viable option for restorative material compared to other restorative materials.
Collapse
Affiliation(s)
- Abdelhak Ouldyerou
- Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Mascara, Algeria
| | - Hassan Mehboob
- Department of Engineering Management, College of Engineering, Prince Sultan University, Riyadh, Saudi Arabia
| | - Ali Mehboob
- Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Ali Merdji
- Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Mascara, Algeria
| | - Laid Aminallah
- Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Mascara, Algeria
| | - Osama M. Mukdadi
- Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, West Virginia, United States of America
| | - Imad Barsoum
- Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
- Department of Engineering Mechanics, Royal Institute of Technology – KTH, Teknikringen, Stockholm, Sweden
| | - Harri Junaedi
- Department of Engineering Management, College of Engineering, Prince Sultan University, Riyadh, Saudi Arabia
| |
Collapse
|
9
|
Zhang C, Wang Y. Biomechanical Analysis of Axial Gradient Porous Dental Implants: A Finite Element Analysis. J Funct Biomater 2023; 14:557. [PMID: 38132811 PMCID: PMC10743419 DOI: 10.3390/jfb14120557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
The porous structure can reduce the elastic modulus of a dental implant and better approximate the elastic characteristics of the material to the alveolar bone. Therefore, it has the potential to alleviate bone stress shielding around the implant. However, natural bone is heterogeneous, and, thus, introducing a porous structure may produce pathological bone stress. Herein, we designed a porous implant with axial gradient variation in porosity to alleviate stress shielding in the cancellous bone while controlling the peak stress value in the cortical bone margin region. The biomechanical distribution characteristics of axial gradient porous implants were studied using a finite element method. The analysis showed that a porous implant with an axial gradient variation in porosity ranging from 55% to 75% was the best structure. Under vertical and oblique loads, the proportion of the area with a stress value within the optimal stress interval at the bone-implant interface (BII) was 40.34% and 34.57%, respectively, which was 99% and 65% higher compared with that of the non-porous implant in the control group. Moreover, the maximum equivalent stress value in the implant with this pore parameter was 64.4 MPa, which was less than 1/7 of its theoretical yield strength. Axial gradient porous implants meet the strength requirements for bone implant applications. They can alleviate stress shielding in cancellous bone without increasing the stress concentration in the cortical bone margin, thereby optimizing the stress distribution pattern at the BII.
Collapse
Affiliation(s)
- Chunyu Zhang
- Xiangya Stomatological Hospital, Central South University, No. 72 Xiangya Street, Kaifu District, Changsha 410008, China;
- Xiangya School of Stomatology, Central South University, No. 72 Xiangya Street, Kaifu District, Changsha 410008, China
- Hunan 3D Printing Engineering Research Center of Oral Care, No. 64 Xiangya Street, Kaifu District, Changsha 410008, China
| | - Yuehong Wang
- Xiangya Stomatological Hospital, Central South University, No. 72 Xiangya Street, Kaifu District, Changsha 410008, China;
- Xiangya School of Stomatology, Central South University, No. 72 Xiangya Street, Kaifu District, Changsha 410008, China
- Hunan 3D Printing Engineering Research Center of Oral Care, No. 64 Xiangya Street, Kaifu District, Changsha 410008, China
| |
Collapse
|
10
|
Li C, Song L, Xiao J, Wu W, Jiang Y, Zhou R, Dai F. Second-generation bone cement-injectable cannulated pedicle screws for osteoporosis: biomechanical and finite element analyses. J Orthop Surg Res 2023; 18:343. [PMID: 37161530 PMCID: PMC10170841 DOI: 10.1186/s13018-023-03752-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/24/2023] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND Biomechanical and finite element analyses were performed to investigate the efficacy of second-generation bone cement-injectable cannulated pedicle screws (CICPS) in osteoporosis. METHODS This study used the biomechanical test module of polyurethane to simulate osteoporotic cancellous bone. Polymethylmethacrylate (PMMA) bone cement was used to anchor the pedicle screws in the module. The specimens were divided into two groups for the mechanical tests: the experimental group (second-generation CICPS) and control group (first-generation CICPS). Safety was evaluated using maximum shear force, static bending, and dynamic bending tests. Biomechanical stability evaluations included the maximum axial pullout force and rotary torque tests. X-ray imaging and computed tomography were used to evaluate the distribution of bone cement 24 h after PMMA injection, and stress distribution at the screw fracture and screw-cement-bone interface was assessed using finite element analysis. RESULTS Mechanical testing revealed that the experimental group (349.8 ± 28.6 N) had a higher maximum axial pullout force than the control group (277.3 ± 8.6 N; P < 0.05). The bending moments of the experimental group (128.5 ± 9.08 N) were comparable to those of the control group (113.4 ± 20.9 N; P > 0.05). The screw-in and spin-out torques of the experimental group were higher than those of the control group (spin-in, 0.793 ± 0.015 vs. 0.577 ± 0.062 N, P < 0.01; spin-out, 0.764 ± 0.027 vs. 0.612 ± 0.049 N, P < 0.01). Bone cement was mainly distributed at the front three-fifths of the screw in both groups, but the distribution was more uniform in the experimental group than in the control group. After pullout, the bone cement was closely connected to the screw, without loosening or fragmentation. In the finite element analysis, stress on the second-generation CICPS was concentrated at the proximal screw outlet, whereas stress on the first-generation CICPS was concentrated at the screw neck, and the screw-bone cement-bone interface stress of the experimental group was smaller than that of the control group. CONCLUSION These findings suggest that second-generation CICPS have higher safety and stability than first-generation CICPS and may be a superior choice for the treatment of osteoporosis.
Collapse
Affiliation(s)
- Congcan Li
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, No. 30 Gaotanyanzheng Street, Chongqing, 400038, China
| | - Lei Song
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, No. 30 Gaotanyanzheng Street, Chongqing, 400038, China
| | - Jun Xiao
- Department of Special Service Physiological Training, Guangzhou Special Service Recuperation Center of PLA Rocket Force, Shantou, 515515, China
| | - Wenwen Wu
- Chinese People's Liberation Army 132U, Tunchang, 571627, China
| | - Yifan Jiang
- Fourth Department of Convalescence, Sanya Rehabilitation and Convalescent Center, Joint Logistics Support Force, Sanya, 572000, China
| | - Rui Zhou
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, No. 30 Gaotanyanzheng Street, Chongqing, 400038, China.
| | - Fei Dai
- Department of Orthopaedics, First Affiliated Hospital, Army Medical University, No. 30 Gaotanyanzheng Street, Chongqing, 400038, China.
| |
Collapse
|
11
|
Duan P, Ding X, Xiong M, Wang P, Xu S, Du W. Biomechanical evaluation of a healed acetabulum with internal fixators: finite element analysis. J Orthop Surg Res 2023; 18:251. [PMID: 36973727 PMCID: PMC10044380 DOI: 10.1186/s13018-023-03736-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
BACKGROUND Treatment of complicated acetabular fracture with internal fixation usually has high risk of failure because of unbefitting fixation. However, evaluation of the biomechanical effect of internal fixation under physiological loading for fracture healing is still generally rarely performed. The purpose of this study is to analyze the biomechanical characteristics of a healed acetabulum with designed internal fixators under gait and to explore the biomechanical relationship between the healed bone and the internal fixator. METHODS A patient-specific finite element model of whole pelvis with designed internal fixators was constructed based on the tomographic digital images, in which the spring element was used to simulate the main ligaments of the pelvis. And the finite element analysis under both the combination loading of different phases and the individual loading of each phase during the gait cycle was carried out. The displacement, von Mises stress, and strain energy of both the healed bone and the fixation were calculated to evaluate the biomechanical characteristics of the healed pelvis. RESULTS Under the combination loading of gait, the maximum difference of displacement between the left hip bone with serious injury and the right hip bone with minor injury is 0.122 mm, and the maximum stress of the left and right hemi-pelvis is 115.5 MPa and 124.28 MPa, respectively. Moreover, the differences of average stress between the bone and internal fixators are in the range of 2.3-13.7 MPa. During the eight phases of gait, the stress distribution of the left and right hip bone is similar. Meanwhile, based on the acetabular three-column theory, the strain energy ratio of the central column is relatively large in stance phases, while the anterior column and posterior column of the acetabular three-column increase in swing phases. CONCLUSIONS The acetabular internal fixators designed by according to the anatomical feature of the acetabulum are integrated into the normal physiological stress conduction of the pelvis. The design and placement of the acetabular internal fixation conforming to the biomechanical characteristics of the bone is beneficial to the anatomical reduction and effective fixation of the fracture, especially for complex acetabular fracture.
Collapse
Affiliation(s)
- Pengyun Duan
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Xiaohong Ding
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China.
| | - Min Xiong
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Panfeng Wang
- Department of Orthopaedics, Changhai Hospital, Naval Medical University, Shanghai, People's Republic of China
| | - Shipeng Xu
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| | - Wei Du
- School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China
| |
Collapse
|