1
|
Hu Y, Chen X, Chu Z, Luo L, Gan Z, Zhong J, Yuan Z, Zhu B, Dong W. Biomechanical Properties of Novel Porous Scaffold Core and Hollow Lateral Hole Pedicle Screws: A Comparative Study in Bama Pigs. Orthop Surg 2024; 16:1718-1725. [PMID: 38766934 PMCID: PMC11216838 DOI: 10.1111/os.14091] [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: 12/12/2023] [Revised: 04/09/2024] [Accepted: 04/23/2024] [Indexed: 05/22/2024] Open
Abstract
OBJECTIVE Screw loosening is a common complication of internal fixation of pedicle screw. Therefore, the development of a pedicle screw with low loosening rate and high biosafety is of great clinical significance. This study aimed to investigate whether the application of a porous scaffold structure can improve the stability of pedicle screws by comparing the biomechanical properties of novel porous scaffold core pedicle screws (PSCPSs) with those of hollow lateral hole pedicle screws (HLHPSs) in a porcine lumbar spine. METHODS Thirty-two pedicle screws of both types were implanted bilaterally into the L1-4 vertebrae of four Bama pigs, with our newly designed PSCPSs on the right and HLHPSs on the left. All the Bama pigs were sacrificed 16 weeks postoperatively, and the lumbar spine was freed into individual vertebrae. Biomechanical properties of both the pedicle screws were evaluated using pull-out tests, as well as cyclic bending and pull-out tests, while the mechanical properties were assessed using three-point bending tests. The data generated were statistically analyzed using paired-sample t-tests and two independent sample t-tests. RESULTS We found that the maximal pull-out forces before and after cyclic bending of the PSCPSs (1161.50 ± 337.98 N and 1075.25 ± 223.33 N) were significantly higher than those of the HLHPSs (948.38 ± 194.32 N and 807.13 ± 242.75 N) (p < 0.05, p < 0.05). In 800 cycles of the bending tests, neither PSCPS nor HLHPS showed loosening or visible detachment, but their maximal pull-out forces after cyclic bending tests decreased compared to those in cycles without cyclic bending tests (7.43% and 14.89%, respectively), with no statistical significance (p > 0.05 and p > 0.05, respectively). Additionally, both screws buckled rather than broke in the three-point bending tests, with no statistically significant differences between the maximal bending load and modulus of elasticity of the two screws (p > 0.05 and p > 0.05, respectively). CONCLUSIONS Compared with the HLHPSs, the PSCPSs have greater pull-out resistance and better fatigue tolerance with appropriate mechanical properties. Therefore, PSCPSs theoretically have significant potential for clinical applications in reducing the incidence of loosening after pedicle screw implantation.
Collapse
Affiliation(s)
- Yong Hu
- Department of Spine SurgeryNingbo No. 6 HospitalNingboChina
| | - Xijiong Chen
- Health Science CenterNingbo UniversityNingboChina
| | - Zhentao Chu
- Health Science CenterNingbo UniversityNingboChina
| | - Linwei Luo
- Health Science CenterNingbo UniversityNingboChina
| | - Zhiwei Gan
- Health Science CenterNingbo UniversityNingboChina
| | - Jianbin Zhong
- Department of Spine SurgeryNingbo No. 6 HospitalNingboChina
| | - Zhenshan Yuan
- Department of Spine SurgeryNingbo No. 6 HospitalNingboChina
| | - Bingke Zhu
- Department of Spine SurgeryNingbo No. 6 HospitalNingboChina
| | - Weixin Dong
- Department of Spine SurgeryNingbo No. 6 HospitalNingboChina
| |
Collapse
|
2
|
Liu F, Feng X, Deng G, Leung F, Wang C, Chen B. Biomechanical comparison of a new undercut thread design vs. the V-shape thread design for pedicle screws. Spine J 2024:S1529-9430(24)00263-8. [PMID: 38843954 DOI: 10.1016/j.spinee.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/19/2024] [Accepted: 05/20/2024] [Indexed: 07/01/2024]
Abstract
BACKGROUND CONTEXT Thread shape is regarded as an important factor influencing the fixation strength and osseointegration of bone screws. However, commercial pedicle screws with a V-shaped thread are prone to generating stress concentration at the bone-screw interface, thereby increasing the risk of screw loosening. Thus, modification of the pedicle-screw thread is imperative. PURPOSE This study aimed to investigate the fixation stability of pedicle screws with the new undercut thread design in comparison to pedicle screws with a V-shaped thread. STUDY DESIGN In vitro cadaveric biomechanical test and finite element analysis (FEA). METHODS Pedicle screws with the undercut thread (characterized by a flat crest feature and a tip-facing undercut feature) were custom-manufactured, whereas those with the V-shaped thread were procured from a commercial supplier. Fixation stability was assessed by the cyclic nonpullout compressive biomechanical testing on cadaveric female osteoporotic vertebrae. The vertical displacement and rotation angle of the 2 types of pedicle screws were calculated every 100 cycles to evaluate their resistance to migration and rotation. FEA was conducted to investigate the stress distribution and bone damage at the bone-screw interface for both types of pedicle screws. RESULTS Biomechanical testing revealed that the pedicle screws with the undercut thread exhibited significantly lower vertical displacement and rotation angles than the pedicle screws with the V-shape thread (P < 0.05). FEA results demonstrated a more uniform stress distribution in the bone surrounding the thread in the undercut design than in the V-shape design. Additionally, bone damage resulting from the pedicle screw was lower in the undercut design than in the V-shape design. CONCLUSIONS Pedicle screws with an undercut thread are less prone to migration and rotation and thus more stable in the bone than those with a V-shape thread. CLINICAL SIGNIFICANCE The undercut thread design may reduce the incidence of pedicle-screw loosening.
Collapse
Affiliation(s)
- Fei Liu
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaoreng Feng
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China; Department of Orthopaedics and Traumatology, Yangjiang People's Hospital, Yangjiang, China
| | - Geyang Deng
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Frankie Leung
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, the University of Hong Kong, Hong Kong SAR, China
| | - Chengyong Wang
- Guangdong Provincial Key Laboratory of Minimally Invasive Surgical Instruments and Manufacturing Technology, Guangdong University of Technology, Guangzhou, China
| | - Bin Chen
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China.
| |
Collapse
|
3
|
Zhan X, Gao F, Yang Y, Tsai T, Wan Z, Yu Y. Effect of Insertional Direction of Pedicle Screw on Screw Loosening: A Biomechanical Study on Synthetic Bone Vertebra under a Physiology-like Load. Orthop Surg 2024; 16:1461-1472. [PMID: 38714346 PMCID: PMC11144517 DOI: 10.1111/os.14080] [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: 02/05/2024] [Revised: 04/06/2024] [Accepted: 04/09/2024] [Indexed: 05/09/2024] Open
Abstract
OBJECTIVES It is now understood that pedicle screw loosening at the implant-bone interface can lead to poor screw-bone interface purchase and decreased fixation stability. Previous biomechanical tests used cadaveric vertebrae and pull-out or torque loads to assess the effect of the insertional direction of pedicle screws on screw loosening. However, these tests faced challenges in matching biomechanical differences among specimens and simulating in vivo loads applied on pedicle screws. This study aimed to evaluate the effect of the insertional direction of pedicle screws on screw loosening using tension-compression-bending loads and synthetic bone vertebrae. METHODS Polyaxial pedicle screws were inserted into nine synthetic bone vertebrae in three directions (three samples per group): cranial, parallel, and caudad (-10°, 0°, +10° of the pedicle screw rod to the upper plane of the vertebra, respectively). Pedicle screws in the vertebrae were loaded using a polyethylene block connected to a material testing machine. Tension-compression-bending loads (100N-250N) with 30,000 cycles were applied to the pedicle screws, and displacements were recorded and then cycle-displacement curve was drawn based on cycle number. Micro-CT scans were performed on the vertebrae after removing the pedicle screws to obtain images of the screw hole, and the screw hole volume was measured using imaging analysis software. Direct comparison of displacements was conducted via cycle-displacement curve. Screw hole volume was analyzed using analysis of variance. The correlation between the displacement, screw hole volume and the direction of pedicle screw was assessed by Spearman correlation analysis. RESULTS The smallest displacements were observed in the caudad group, followed by the parallel and cranial groups. The caudad group had the smallest screw hole volume (p < 0.001 and p = 0.009 compared to the cranial and parallel groups, respectively), while the volume in the parallel group was greater than that in the cranial group (p = 0.003). Correlation analysis revealed that the insertional direction of the pedicle screw was associated with the displacement (p = -0.949, p < 0.001) and screw hole volume (p = -0.944, p < 0.001). CONCLUSION Strong correlations were found between the insertional direction of the pedicle screw and relevant parameters, including displacement and screw hole volume. Pedicle screw insertion in the caudad direction resulted in the least pedicle screw loosening.
Collapse
Affiliation(s)
- Xuqiang Zhan
- Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration, Ministry of Education, Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
| | - Feng Gao
- Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration, Ministry of Education, Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
- Yuyao Maternity and Child Health Care Hospital (Yuyao Second People's Hospital)ZhejiangChina
| | - Yangyang Yang
- School of Biomedical Engineering & Med‐X Research Institute, Shanghai Jiao Tong UniversityShanghaiChina
| | - Tsung‐Yuan Tsai
- School of Biomedical Engineering & Med‐X Research Institute, Shanghai Jiao Tong UniversityShanghaiChina
| | - Zongmiao Wan
- The First Affiliated Hospital of NanChang UniversityNanchangChina
| | - Yan Yu
- Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration, Ministry of Education, Department of Spine SurgeryTongji Hospital, School of Medicine, Tongji UniversityShanghaiChina
| |
Collapse
|
4
|
Leblond L, Godio-Raboutet Y, Glard Y, La Greca R, Clement T, Evin M. Assessment of the tolerance angle for pedicle screw insertion. Med Biol Eng Comput 2024; 62:1265-1275. [PMID: 38177833 DOI: 10.1007/s11517-023-03002-x] [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: 09/08/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024]
Abstract
Cannulation process intervenes before implantation of pedicle screw and depends on the surgeon's experience. A reliable experimental protocol has been developed for the characterization of the slipping behavior of the surgical tool on the cortical shell simulated by synthetic materials. Three types of synthetic foam samples with three different densities were tested using an MTS Acumen 3 A/T electrodynamic device with a tri-axis 3 kN Kistler load cell mounted on a surgical tool, moving at a constant rotational speed of 10° mm-1 and performing a three-step cannulation test. Cannulation angle varied between 10° and 30°. Synthetic samples were scanned after each tests, and cannulation coefficient associated to each perforation section was computed. Reproducibility tests resulted in an ICC for Sawbone samples of 0.979 (p < 0.001) and of 0.909 (p < 0.001) for Creaplast and Sawbone samples. Cannulation coefficient and maximum force in Z-axis are found the best descriptors of the perforation. Angular threshold for perforation prediction was found to be 17.5° with an area under the curve of the Receiver Operating Characteristic of 89.5%. This protocol characterizes the cannulation process before pedicle screw insertion and identifies the perforation tool angle until which the surgical tool slips on the cortical shell depending on bone quality.
Collapse
Affiliation(s)
- Lugdivine Leblond
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Faculté de Medecine Secteur-Nord, Aix-Marseille University, University of Gustave Eiffel, LBA, Marseille, France
| | - Yves Godio-Raboutet
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Faculté de Medecine Secteur-Nord, Aix-Marseille University, University of Gustave Eiffel, LBA, Marseille, France
| | - Yann Glard
- Department of Paediatric Orthopaedics, Saint Joseph Hospital, Marseille, France
| | - Raphael La Greca
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Faculté de Medecine Secteur-Nord, Aix-Marseille University, University of Gustave Eiffel, LBA, Marseille, France
| | - Thomas Clement
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Faculté de Medecine Secteur-Nord, Aix-Marseille University, University of Gustave Eiffel, LBA, Marseille, France
| | - Morgane Evin
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Faculté de Medecine Secteur-Nord, Aix-Marseille University, University of Gustave Eiffel, LBA, Marseille, France.
| |
Collapse
|
5
|
Costăchescu B, Niculescu AG, Grumezescu AM, Teleanu DM. Screw Osteointegration-Increasing Biomechanical Resistance to Pull-Out Effect. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5582. [PMID: 37629873 PMCID: PMC10456840 DOI: 10.3390/ma16165582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023]
Abstract
Spinal disorders cover a broad spectrum of pathologies and are among the most prevalent medical conditions. The management of these health issues was noted to be increasingly based on surgical interventions. Spinal fixation devices are often employed to improve surgery outcomes, increasing spinal stability, restoring structural integrity, and ensuring functionality. However, most of the currently used fixation tools are fabricated from materials with very different mechanical properties to native bone that are prone to pull-out effects or fail over time, requiring revision procedures. Solutions to these problems presently exploited in practice include the optimal selection of screw shape and size, modification of insertion trajectory, and utilization of bone cement to reinforce fixation constructs. Nevertheless, none of these methods are without risks and limitations. An alternative option to increasing biomechanical resistance to the pull-out effect is to tackle bone regenerative capacity and focus on screw osteointegration properties. Osteointegration was reportedly enhanced through various optimization strategies, including use of novel materials, surface modification techniques (e.g., application of coatings and topological optimization), and utilization of composites that allow synergistic effects between constituents. In this context, this paper takes a comprehensive path, starting with a brief presentation of spinal fixation devices, moving further to observations on how the pull-out strength can be enhanced with existing methods, and further focusing on techniques for implant osteointegration improvement.
Collapse
Affiliation(s)
- Bogdan Costăchescu
- “Gr. T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
- “Prof. Dr. N. Oblu” Emergency Clinical Hospital, 700309 Iasi, Romania
| | - Adelina-Gabriela Niculescu
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Politehnica University of Bucharest, 011061 Bucharest, Romania
| | - Alexandru Mihai Grumezescu
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Politehnica University of Bucharest, 011061 Bucharest, Romania
- Academy of Romanian Scientists, Ilfov No. 3, 050044 Bucharest, Romania
| | | |
Collapse
|
6
|
Sadighi A, Taghvaei M, Taheri M, Oeth D, Siegler S, Schaer TP, R Najafi A. Numerical analysis of the mechanical response of novel swelling bone implants in polyurethane foams. J Mech Behav Biomed Mater 2023; 143:105871. [PMID: 37187154 DOI: 10.1016/j.jmbbm.2023.105871] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/17/2023]
Abstract
In this study, a numerical framework was developed in order to analyze the swelling properties, mechanical response and fixation strength of swelling bone anchors. Using this framework, fully porous and solid implants, along with a novel hybrid design (consisting of a solid core and a porous sleeve), were modeled and studied. Free swelling experiments were conducted to investigate their swelling characteristics. The finite element model of swelling was validated using the conducted free swelling. Compared with the experimental data, results obtained from the finite element analysis proved the reliability of this frame-work. Afterwards, the swelling bone anchors were studied embedded in artificial bones with different densities with two different interface properties: considering frictional interface between the bone anchors and artificial bones (simulating the stages prior to osteointegration, when the bone and implant are not fully bonded and the surface of the implant can slide along the interface), and perfectly bonded (simulating the stages subsequent to osteointegration, when the bone and implant are fully bonded). It was observed that the swelling considerably decreases while the average radial stress on the lateral surface of the swelling bone anchor surges in the denser artificial bones. Ultimately, the pull-out experiments and simulations of the swelling bone anchors from the artificial bones were conducted to look into the fixation strength of the swelling bone anchors. It was found that the hybrid swelling bone anchor exhibits mechanical and swelling properties close to those of solid bone anchors, while also bone in-growth is expected to happen, which is an integral factor to these bone anchors.
Collapse
Affiliation(s)
- Amirreza Sadighi
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Moein Taghvaei
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Mehrangiz Taheri
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Delaney Oeth
- Department of Clinical Studies New Bolton Center, University of Pennsylvania School of Veterinary Medicine, PA, 19348, USA
| | - Sorin Siegler
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA
| | - Thomas P Schaer
- Department of Clinical Studies New Bolton Center, University of Pennsylvania School of Veterinary Medicine, PA, 19348, USA
| | - Ahmad R Najafi
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, 19104, USA.
| |
Collapse
|
7
|
Muhayudin NA, Basaruddin KS, Ijaz MF, Daud R. Finite Element Modelling of a Synthetic Paediatric Spine for Biomechanical Investigation. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4514. [PMID: 37444827 DOI: 10.3390/ma16134514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/31/2023] [Accepted: 06/09/2023] [Indexed: 07/15/2023]
Abstract
Studies on paediatric spines commonly use human adult or immature porcine spines as specimens, because it is difficult to obtain actual paediatric specimens. There are quite obvious differences, such as geometry, size, bone morphology, and orientation of facet joint for these specimens, compared to paediatric spine. Hence, development of synthetic models that can behave similarly to actual paediatric spines, particularly in term of range of motion (ROM), could provide a significant contribution for paediatric spine research. This study aims to develop a synthetic paediatric spine using finite element modelling and evaluate the reliability of the model by comparing it with the experimental data under certain load conditions. The ROM of the paediatric spine was measured using a validated FE model at ±0.5 Nm moment in order to determine the moment required by the synthetic spine to achieve the same ROM. The results showed that the synthetic spine required two moments, ±2 Nm for lateral-bending and axial rotation, and ±3 Nm for flexion-extension, to obtain the paediatric ROM. The synthetic spine was shown to be stiffer in flexion-extension but more flexible in lateral bending than the paediatric FE model, possibly as a result of the intervertebral disc's simplified shape and the disc's weak bonding with the vertebrae. Nevertheless, the synthetic paediatric spine has promising potential in the future as an alternative paediatric spine model for biomechanical investigation of paediatric cases.
Collapse
Affiliation(s)
- Nor Amalina Muhayudin
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Campus, Arau 02600, Malaysia
| | - Khairul Salleh Basaruddin
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Campus, Arau 02600, Malaysia
- Sports Engineering Research Centre (SERC), Universiti Malaysia Perlis, Arau 02600, Malaysia
| | - Muhammad Farzik Ijaz
- Mechanical Engineering Department, College of Engineering, King Saud University, Riyadh 11421, Saudi Arabia
- King Salman Center for Disability Research, Riyadh 11614, Saudi Arabia
| | - Ruslizam Daud
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Pauh Putra Campus, Arau 02600, Malaysia
- Sports Engineering Research Centre (SERC), Universiti Malaysia Perlis, Arau 02600, Malaysia
| |
Collapse
|
8
|
Song F, Liu Y, Fu R, Gao X, Iqbal K, Yang D, Liu Y, Yang H. Craniocaudal toggling increases the risk of screw loosening in osteoporotic vertebrae. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 238:107625. [PMID: 37263117 DOI: 10.1016/j.cmpb.2023.107625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/03/2023]
Abstract
BACKGROUND AND OBJECTIVE Screw loosening remains a prominent problem for osteoporotic patients undergoing pedicle screw fixation surgeries but its underlying mechanisms are not fully understood. This study sought to examine the interactive effect of craniocaudal or axial cyclic loading (toggling) and osteoporosis on screw fixation. METHODS QCT-based finite element models of normal (n = 7; vBMD = 156 ± 13 mg/cm3) and osteoporotic vertebrae (n = 7; vBMD = 72 ± 6 mg/cm3) were inserted with pedicle screws and loaded with or without craniocaudal toggling. Among them, a representative normal vertebra (age: 55; BMD: 140 mg/cm3) and an osteoporotic vertebra (age: 64; BMD: 79 mg/cm3) were also loaded with or without axial toggling. The individual and interactive effects of craniocaudal toggling and osteoporosis on screw fixation strength (the force when the pull-up displacement of the screw head reached 1 mm) and bone tissue failure (characterized by equivalent plastic strain) were examined by repeated measure ANOVA. RESULTS A significant interactive effect between craniocaudal toggling and osteoporosis on screw fixation strength was detected (p = 0.008). Specifically, craniocaudal toggling led to a marked decrease in the fixation strength (68%, p < 0.05) and stiffness (83%, p < 0.05) only in the osteoporotic vertebrae but had no effect on screw fixation strength and stiffness of the normal vertebrae (p > 0.05). Likewise, most of the bone tissues around the screw in the osteoporotic vertebrae yielded following craniocaudal toggling whereas this result was not seen in the normal vertebrae. The axial toggling had no significant effect on bone tissue failure as well as pedicle screw fixation in normal or osteoporotic vertebrae. CONCLUSIONS Craniocaudal toggling substantially reduces the screw fixation strength of the osteoporotic vertebrae by progressively increasing tissue failure around the screw, and therefore may contribute to the higher rates of screw loosening in osteoporotic compared to normal patients, whereas axial toggling is not a risk factor for pedicle screw loosening in normal or osteoporotic patients.
Collapse
Affiliation(s)
- Fei Song
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Yang Liu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Ruisen Fu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Xing Gao
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Kamran Iqbal
- Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing, China
| | - Dongyue Yang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Yuxuan Liu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Haisheng Yang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing, China.
| |
Collapse
|
9
|
Zhang XN, Zhou LJ, Su QJ, Guan L, Li DY, Pei BQ, Pan AX, Yang HH, Ding HT, Liu YZ, Hai Y. Accuracy of cortical bone trajectory screw fixation guided by spinous process clamp guide in lumbosacral vertebrae: A cadaver study. Int J Med Robot 2023; 19:e2484. [PMID: 36413096 DOI: 10.1002/rcs.2484] [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: 08/17/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND The purpose of this study was to access the accuracy of cortical bone trajectory screw placement guided by spinous process clamp (SPC). METHODS Eight formalin-treated cadaveric lumbar specimens with T12-S1 were used. A total of 96 screws were implanted in eight lumbar specimens. RESULTS In the freehand (FH) group, clinically acceptable placement (grade A and B) was 40 screws (83.3%), meanwhile 44 screws (91.7%) in the SPC guide group (p = 0.217). The grade A screws in the SPC guide group were much more than that in the FH group (n = 40 vs. n = 31, p = 0.036). The misplacement screws (grade C, D, and E) and proximal facet joint violation (FJV) in the SPC group was comparable to the FH group. CONCLUSIONS This cadaveric study demonstrate that implanting CBT screws guided by SPC guide was more accuracy and reduces severe deviations in important directions.
Collapse
Affiliation(s)
- Xi-Nuo Zhang
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Li-Jin Zhou
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Qing-Jun Su
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Li Guan
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Dong-Yue Li
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Bao-Qing Pei
- Beijing Key Laboratory for Design and Evaluation Technology of Advanced Implantable & Interventional Medical Devices, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ai-Xing Pan
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Hong-Hao Yang
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Hong-Tao Ding
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Yu-Zeng Liu
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Yong Hai
- Department of Orthopedic Surgery, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
10
|
Li JC, Yang ZQ, Xie TH, Song ZT, Song YM, Zeng JC. Deterioration of the fixation segment’s stress distribution and the strength reduction of screw holding position together cause screw loosening in ALSR fixed OLIF patients with poor BMD. Front Bioeng Biotechnol 2022; 10:922848. [PMID: 36110315 PMCID: PMC9468878 DOI: 10.3389/fbioe.2022.922848] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
The vertebral body’s Hounsfield unit (HU) value can credibly reflect patients’ bone mineral density (BMD). Given that poor bone-screw integration initially triggers screw loosening and regional differences in BMD and strength in the vertebral body exist, HU in screw holding planes should better predict screw loosening. According to the stress shielding effect, the stress distribution changes in the fixation segment with BMD reduction should be related to screw loosening, but this has not been identified. We retrospectively collected the radiographic and demographic data of 56 patients treated by single-level oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) screw fixation. BMD was identified by measuring HU values in vertebral bodies and screw holding planes. Regression analyses identified independent risk factors for cranial and caudal screw loosening separately. Meanwhile, OLIF with ALSR fixation was numerically simulated; the elastic modulus of bony structures was adjusted to simulate different grades of BMD reduction. Stress distribution changes were judged by computing stress distribution in screws, bone-screw interfaces, and cancellous bones in the fixation segment. The results showed that HU reduction in vertebral bodies and screw holding planes were independent risk factors for screw loosening. The predictive performance of screw holding plane HU is better than the mean HU of vertebral bodies. Cranial screws suffer a higher risk of screw loosening, but HU was not significantly different between cranial and caudal sides. The poor BMD led to stress concentrations on both the screw and bone-screw interfaces. Biomechanical deterioration was more severe in the cranial screws than in the caudal screws. Additionally, lower stress can also be observed in fixation segments’ cancellous bone. Therefore, a higher proportion of ALSR load transmission triggers stress concentration on the screw and bone-screw interfaces in patients with poor BMD. This, together with decreased bony strength in the screw holding position, contributes to screw loosening in osteoporotic patients biomechanically. The trajectory optimization of ALSR screws based on preoperative HU measurement and regular anti-osteoporosis therapy may effectively reduce the risk of screw loosening.
Collapse
Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhi-Qiang Yang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| |
Collapse
|
11
|
Li JC, Xie TH, Zhang Z, Song ZT, Song YM, Zeng JC. The Mismatch Between Bony Endplates and Grafted Bone Increases Screw Loosening Risk for OLIF Patients With ALSR Fixation Biomechanically. Front Bioeng Biotechnol 2022; 10:862951. [PMID: 35464717 PMCID: PMC9023805 DOI: 10.3389/fbioe.2022.862951] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/24/2022] [Indexed: 12/26/2022] Open
Abstract
The mismatch between bony endplates (BEPs) and grafted bone (GB) triggers several complications biomechanically. However, no published study has identified whether this factor increases the risk of screw loosening by deteriorating the local stress levels. This study aimed to illustrate the biomechanical effects of the mismatch between BEP and GB and the related risk of screw loosening. In this study, radiographic and demographic data of 56 patients treated by single segment oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) fixation were collected retrospectively, and the match sufficiency between BEP and GB was measured and presented as the grafted bony occupancy rate (GBOR). Data in patients with and without screw loosening were compared; regression analyses identified independent risk factors. OLIF with different GBORs was simulated in a previously constructed and validated lumbosacral model, and biomechanical indicators related to screw loosening were computed in surgical models. The radiographic review and numerical simulations showed that the coronal plane’s GBOR was significantly lower in screw loosening patients both in the cranial and caudal vertebral bodies; the decrease in the coronal plane’s GBOR has been proven to be an independent risk factor for screw loosening. In addition, numerical mechanical simulations showed that the poor match between BEP and GB will lead to stress concentration on both screws and bone-screw interfaces. Therefore, we can conclude that the mismatch between the BEP and GB will increase the risk of screw loosening by deteriorating local stress levels, and the increase in the GBOR by modifying the OLIF cage’s design may be an effective method to optimize the patient’s prognosis.
Collapse
Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhuang Zhang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| |
Collapse
|
12
|
Yao Y, Mo Z, Wu G, Guo J, Li J, Wang L, Fan Y. A personalized 3D-printed plate for tibiotalocalcaneal arthrodesis: Design, fabrication, biomechanical evaluation and postoperative assessment. Comput Biol Med 2021; 133:104368. [PMID: 33864971 DOI: 10.1016/j.compbiomed.2021.104368] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/09/2021] [Accepted: 03/28/2021] [Indexed: 12/11/2022]
Abstract
Personalized plates (P-Plates) could provide improved clinical outcomes in joint fusion by enabling perfect geometric matching between irregular bone and implants. However, there is no unified application framework for P-Plates for joint fusion. The objective of this study was to develop such a framework for P-Plates for tibiotalocalcaneal arthrodesis. A patient-specific bone model was constructed based on CT images, and the P-Plate was preliminarily designed to match the bones. Finite element method was used to optimize the stress distribution and to evaluate the biomechanical performance of the P-Plate by comparing it with a traditional plate (T-Plate). Then, the P-Plate was manufactured via electron beam melting and implanted into the foot of a patient. Increasing the size of the preliminary designed plate alleviated the stress concentration and reduced the risk of failure. The maximum stresses of the plate and screw (214.3 MPa, 99.05 MPa) and the maximum tensile force of the screw in the P-Plate (181.4 N) fixation system were lower than those in the T-Plate (217.4 MPa, 255.4 MPa, and 230.1 N, respectively). The P-Plate was well-matched to the bone, and no complications occurred. The P-Plate achieved American Orthopaedic Foot & Ankle Society and Short-Form-36 scores of 64 and 75, respectively, 36 months post operation, which suggests that it could improve clinical outcomes. The design and fabrication methods, as well as mechanical and postoperative performance evaluation methods, for the P-Plate were systematically developed and provide a reference for constructing a unified application framework for P-Plate use in tibiotalocalcaneal arthrodesis.
Collapse
Affiliation(s)
- Yan Yao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 100191, Beijing, China.
| | - Zhongjun Mo
- Key Laboratory of Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Centre for Rehabilitation Technical Aids, 100176, Beijing, China.
| | - Gang Wu
- Key Laboratory of Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Centre for Rehabilitation Technical Aids, 100176, Beijing, China; Rehabilitation Hospital, National Research Center for Rehabilitation Technical Aids, 100176, Beijing, China.
| | - Junchao Guo
- Key Laboratory of Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Centre for Rehabilitation Technical Aids, 100176, Beijing, China.
| | - Jian Li
- Key Laboratory of Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Centre for Rehabilitation Technical Aids, 100176, Beijing, China.
| | - Lizhen Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 100191, Beijing, China.
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 100191, Beijing, China; Key Laboratory of Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Centre for Rehabilitation Technical Aids, 100176, Beijing, China; Rehabilitation Hospital, National Research Center for Rehabilitation Technical Aids, 100176, Beijing, China; School of Engineering Medicine, Beihang University, 100191, Beijing, China.
| |
Collapse
|
13
|
Horak Z, Tichy P, Dvorak K, Vilimek M. Application of an Arbitrary Lagrangian-Eulerian Method to Modelling the Machining of Rigid Polyurethane Foam. MATERIALS 2021; 14:ma14071654. [PMID: 33800540 PMCID: PMC8037215 DOI: 10.3390/ma14071654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022]
Abstract
Rigid polyurethane (PUR) foam, which has an extensive range of construction, engineering, and healthcare applications, is commonly used in technical practice. PUR foam is a brittle material, and its mechanical material properties are strongly dependent on temperature and strain rate. Our work aimed to create a robust FE model enabling the simulation of PUR foam machining and verify the results of FE simulations using the experiments' results. We created a complex FE model using the Arbitrary Lagrangian-Eulerian (ALE) method. In the developed FE model, a constitutive material model was used in which the dependence of the strain rate, damage initiation, damage propagation, and plastic deformation on temperature was implemented. To verify the FE analyses' results with experimentally measured data, we measured the maximum temperature during PUR foam drilling with different densities (10, 25, and 40 PCF) and at various cutting speeds. The FE models with a constant cutting speed of 500 mm/s and various PUR foam densities led to slightly higher Tmax values, where the differences were 13.1% (10 PCF), 7.0% (25 PCF), and 10.0% (40 PCF). The same situation was observed for the simulation results related to various cutting speeds at a constant PUR foam density of 40 PCF, where the differences were 25.3% (133 mm/s), 10.1% (500 mm/s), and 15.5% (833 mm/s). The presented results show that the ALE method provides a good match with the experimental data and can be used for accurate simulation of rigid PUR foam machining.
Collapse
Affiliation(s)
- Zdenek Horak
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic;
- Correspondence: ; Tel.: +420-773-778-948
| | - Petr Tichy
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic; (P.T.); (M.V.)
| | - Karel Dvorak
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic;
| | - Miloslav Vilimek
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic; (P.T.); (M.V.)
| |
Collapse
|
14
|
Tan QC, Wang D, Yang Z, Zhao XL, Zhang Y, Yan YB, Feng YF, Lei W, Zhao X, Wu ZX. Implant Preservation versus Implant Replacement in Revision Surgery for Adjacent Segment Disease After Thoracolumbar Instrumentation: A Retrospective Study of 43 Patients. World Neurosurg 2021; 150:e511-e519. [PMID: 33744424 DOI: 10.1016/j.wneu.2021.03.046] [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: 12/29/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the mechanical properties of a new connector rod aiming to preserve implants in revision surgery (RS) for adjacent segment disease, a problematic complication of instrumented spinal fusion, and to assess its clinical applicability. METHODS The mechanical properties of the connector-rod construct (implant preservation) and traditional rod construct (implant replacement) were evaluated and compared. Forty-three patients underwent RS for adjacent segment disease in the thoracolumbar spine with implant preservation or replacement, and radiological and clinical outcomes were assessed. RESULTS Mechanical properties in group A were comparable to those in group B. Total mean time from prior surgery to RS was 6.86 ± 1.08 years. Surgical time and blood loss values of group A were 40.14% and 29.29% statistically significantly smaller than values of group B. In group B, 12% (3/25) of patients developed surgical site infections. In both groups, the visual analog scale leg score decreased significantly after RS. Early postoperative (at 1-month and 3-month follow-up) Oswestry Disability Index and visual analog scale back scores of group A were significantly lower than those of group B; the difference in the visual analog scale back score between groups was significant until the 6-month follow-up. No implant failures occurred, and spinal fusion was achieved in all cases. CONCLUSIONS The connector rod is considered safe and can reduce the surgical time, blood loss, risk of complications, and medical costs. Better early postoperative clinical outcomes can be achieved with the rod owing to less surgical trauma.
Collapse
Affiliation(s)
- Quan-Chang Tan
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China; Department of Orthopaedics, Air Force Hospital of Eastern Theater Command, Nanjing, China
| | - Di Wang
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Zhao Yang
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Xiao-Lei Zhao
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Yang Zhang
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Ya-Bo Yan
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Ya-Fei Feng
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Wei Lei
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Xiong Zhao
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Zi-Xiang Wu
- Department of Orthopaedics, Xijing Hospital, Air Force Medical University, Xi'an, China.
| |
Collapse
|
15
|
Horak Z, Dvorak K, Zarybnicka L, Vojackova H, Dvorakova J, Vilimek M. Experimental Measurements of Mechanical Properties of PUR Foam Used for Testing Medical Devices and Instruments Depending on Temperature, Density and Strain Rate. MATERIALS 2020; 13:ma13204560. [PMID: 33066467 PMCID: PMC7602287 DOI: 10.3390/ma13204560] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/04/2020] [Accepted: 10/06/2020] [Indexed: 11/25/2022]
Abstract
Rigid polyurethane (PUR) foam is products used as a biomedical material for medical device testing. Thermal stability is a very important parameter for evaluating the feasibility of use for testing surgical instrument load during drilling. This work aimed to perform experimental measurements to determine the dependence of the mechanical properties of a certified PUR on temperature, strain rate and density. Experimental measurements were realised for three types of the PUR samples with different density 10, 25 and 40 pounds per cubic foot. The samples were characterised in terms of their mechanical properties evaluated from tensile and compression tests at temperatures of 25 °C, 90 °C and 155 °C. Furthermore, the structures of the samples were characterised using optical microscope, their thermal properties were characterised by thermogravimetric analysis, and their density and stiffness with the effect of temperature was monitored. The results show that it is optimal not only for mechanical testing but also for testing surgical instruments that generate heat during machining. On the basis of experimental measurements and evaluations of the obtained values, the tested materials are suitable for mechanical testing of medical devices. At the same time, this material is also suitable for testing surgical instruments that generate heat during machining.
Collapse
Affiliation(s)
- Zdenek Horak
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic; (K.D.); (L.Z.); (H.V.); (J.D.)
- Correspondence: ; Tel.: +420-773-778-948
| | - Karel Dvorak
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic; (K.D.); (L.Z.); (H.V.); (J.D.)
| | - Lucie Zarybnicka
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic; (K.D.); (L.Z.); (H.V.); (J.D.)
- Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Centre Telc, Prosecka 809/76, 19000 Prague, Czech Republic
| | - Hana Vojackova
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic; (K.D.); (L.Z.); (H.V.); (J.D.)
| | - Jana Dvorakova
- Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic; (K.D.); (L.Z.); (H.V.); (J.D.)
| | - Miloslav Vilimek
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic;
| |
Collapse
|
16
|
Zhang T, Ren X, Feng X, Diwan A, Luk KDK, Lu WW, Wong TM, Li C, Cheung JPY. Failure mechanisms of pedicle screws and cortical screws fixation under large displacement: A biomechanical and microstructural study based on a clinical case scenario. J Mech Behav Biomed Mater 2020; 104:103646. [DOI: 10.1016/j.jmbbm.2020.103646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 10/25/2022]
|
17
|
Experimental validation of adaptive pedicle screws—a novel implant concept using shape memory alloys. Med Biol Eng Comput 2019; 58:55-65. [DOI: 10.1007/s11517-019-02059-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 11/02/2019] [Indexed: 12/28/2022]
|