1
|
Nie MD, Li N, Huang ZB, Cheng RS, Zhang Q, Fu LJ, Cheng CK. Innovative hydrogel-patch combination for large annulus fibrosus defects: a prospective approach to address herniation recurrence. Spine J 2024:S1529-9430(24)00300-0. [PMID: 38914373 DOI: 10.1016/j.spinee.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/10/2024] [Accepted: 06/13/2024] [Indexed: 06/26/2024]
Abstract
BACKGROUND CONTEXT Large annulus fibrosus (AF) defects often lead to a high rate of reherniation, particularly in the medial AF region, which has limited self-healing capabilities. The increasing prevalence of herniated discs underscores the need for effective repair strategies. PURPOSE The objectives of this study were to design an AF repair technique to reduce solve the current problems of insufficient mechanical properties and poor sealing capacity. STUDY DESIGN In vitro biomechanical experiments and finite element analysis. METHODS The materials used in this study were patches and hydrogels with good biocompatibility and sufficient mechanical properties to withstand loading in the lumbar spine. Five repair techniques were assessed in this study: hydrogel filler (HF), AF patch medial barrier (MB), AF patch medial barrier and hydrogel filler (MB&HF), AF patch medial-lateral barrier (MLB), and AF patch medial-lateral barrier and hydrogel filler (MLB&HF). The repair techniques were subjected to in vitro testing (400 N axial compression and 0-500 N fatigue loading at 5Hz) and finite element analysis (400 N axial compression) to evaluate the effectiveness at repairing large AF defects. The evaluation included repair tightness, spinal stability, and fatigue resistance. RESULTS From the in vitro testing, the failure load of the repair techniques was in the following order HF MLB >MB&HF >MLB&HF. CONCLUSIONS The combined use of patches and hydrogels exhibited promising mechanical properties postdiscectomy, providing a promising solution for addressing large AF defects and improving disc stability. CLINICAL SIGNIFICANCE This study introduces a promising method for repairing large annular fissure (AF) defects after disc herniation, combining patch repair with a hydrogel filler. These techniques hold potential for developing clinical AF repair products to address this challenging issue.
Collapse
Affiliation(s)
- Mao-Dan Nie
- School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954 Huashan Road, Xuhui District, Shanghai, 200030, China
| | - Na Li
- Department of Absorbable Materials Research and Development, Beijing Naton Medical Institute, No.9 Chengwan Street, Haidian District, Beijing, 100143, China
| | - Ze-Bin Huang
- Department of Spine Surgery, First Affiliated Hospital of Second Military Medical University, No. 168 Changhai Road, Yangpu District, Shanghai, 200433, China
| | - Rong-Shan Cheng
- School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954 Huashan Road, Xuhui District, Shanghai, 200030, China
| | - Qiang Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954 Huashan Road, Xuhui District, Shanghai, 200030, China
| | - Ling-Jie Fu
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Manufacturing Bureau Road, Huangpu District, Shanghai, 200011, China
| | - Cheng-Kung Cheng
- School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954 Huashan Road, Xuhui District, Shanghai, 200030, China.
| |
Collapse
|
2
|
Liu Q, Liang XF, Wang AG, Liu Y, Jia TJ, Li K, Zhang CQ. Failure mechanical properties of lumbar intervertebral disc under high loading rate. J Orthop Surg Res 2024; 19:15. [PMID: 38167031 PMCID: PMC10763340 DOI: 10.1186/s13018-023-04424-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: 10/16/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Lumbar disc herniation (LDH) is the main clinical cause of low back pain. The pathogenesis of lumbar disc herniation is still uncertain, while it is often accompanied by disc rupture. In order to explore relationship between loading rate and failure mechanics that may lead to lumbar disc herniation, the failure mechanical properties of the intervertebral disc under high rates of loading were analyzed. METHOD Bend the lumbar motion segment of a healthy sheep by 5° and compress it to the ultimate strength point at a strain rate of 0.008/s, making a damaged sample. Within the normal strain range, the sample is subjected to quasi-static loading and high loading rate at different strain rates. RESULTS For healthy samples, the stress-strain curve appears collapsed only at high rates of compression; for damaged samples, the stress-strain curves collapse both at quasi-static and high-rate compression. For damaged samples, the strengthening stage becomes significantly shorter as the strain rate increases, indicating that its ability to prevent the destruction is significantly reduced. For damaged intervertebral disc, when subjected to quasi-static or high rates loading until failure, the phenomenon of nucleus pulposus (NP) prolapse occurs, indicating the occurrence of herniation. When subjected to quasi-static loading, the AF moves away from the NP, and inner AF has the greatest displacement; when subjected to high rates loading, the AF moves closer to the NP, and outer AF has the greatest displacement. The Zhu-Wang-Tang (ZWT) nonlinear viscoelastic constitutive model was used to describe the mechanical behavior of the intervertebral disc, and the fitting results were in good agreement with the experimental curve. CONCLUSION Experimental results show that, both damage and strain rate have a significant effect on the mechanical behavior of the disc fracture. The research work in this article has important theoretical guiding significance for preventing LDH in daily life.
Collapse
Affiliation(s)
- Qing Liu
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300354, People's Republic of China
- Department of Mechanics, Tianjin University, Tianjin, 300354, People's Republic of China
- Tianjin Key Laboratory of Nonlinear Dynamics and Control, Tianjin, 300354, People's Republic of China
| | - Xiao-Feng Liang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300354, People's Republic of China
| | - Ai-Guo Wang
- Affiliated Hospital of Tianjin Academia Sinica, Tianjin, 300120, People's Republic of China
| | - Ying Liu
- Affiliated Hospital of Tianjin Academia Sinica, Tianjin, 300120, People's Republic of China
| | - Tong-Ju Jia
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300354, People's Republic of China
| | - Kun Li
- Tianjin Key Laboratory of Film Electronic and Communication Device, Tianjin University of Technology, Tianjin, 300384, People's Republic of China.
| | - Chun-Qiu Zhang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300354, People's Republic of China
| |
Collapse
|
3
|
Orozco GA, Tanska P, Gustafsson A, Korhonen RK, Isaksson H. Crack propagation in articular cartilage under cyclic loading using cohesive finite element modeling. J Mech Behav Biomed Mater 2022; 131:105227. [DOI: 10.1016/j.jmbbm.2022.105227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/01/2022] [Accepted: 04/02/2022] [Indexed: 11/28/2022]
|
4
|
Bansal S, Meadows KD, Miller LM, Saleh KS, Patel JM, Stoeckl BD, Lemmon EA, Hast MW, Zgonis MH, Scanzello CR, Elliott DM, Mauck RL. Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model. Orthop J Sports Med 2021; 9:23259671211035444. [PMID: 34796238 PMCID: PMC8593308 DOI: 10.1177/23259671211035444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/04/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models. PURPOSE/HYPOTHESIS In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint. STUDY DESIGN Controlled laboratory study. METHODS Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium. RESULTS Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point. CONCLUSION Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage. CLINICAL RELEVANCE More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule-driven interventions after injury to prevent OA progression.
Collapse
Affiliation(s)
- Sonia Bansal
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kyle D. Meadows
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Kamiel S. Saleh
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Jay M. Patel
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Brendan D. Stoeckl
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Elisabeth A. Lemmon
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Michael W. Hast
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Miltiadis H. Zgonis
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Carla R. Scanzello
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Division of Rheumatology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dawn M. Elliott
- Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Robert L. Mauck, PhD, Department of Orthopedic Surgery, University of Pennsylvania, 3450 Hamilton Walk, 371 Stemmler Hall, Philadelphia, PA 19104, USA () (Twitter: @MauckLab)
| |
Collapse
|
5
|
te Moller NCR, Mohammadi A, Plomp S, Serra Bragança FM, Beukers M, Pouran B, Afara IO, Nippolainen E, Mäkelä JTA, Korhonen RK, Töyräs J, Brommer H, van Weeren PR. Structural, compositional, and functional effects of blunt and sharp cartilage damage on the joint: A 9-month equine groove model study. J Orthop Res 2021; 39:2363-2375. [PMID: 33368588 PMCID: PMC8597083 DOI: 10.1002/jor.24971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/09/2020] [Accepted: 12/21/2020] [Indexed: 02/04/2023]
Abstract
This study aimed to quantify the long-term progression of blunt and sharp cartilage defects and their effect on joint homeostasis and function of the equine carpus. In nine adult Shetland ponies, the cartilage in the radiocarpal and middle carpal joint of one front limb was grooved (blunt or sharp randomized). The ponies were subjected to an 8-week exercise protocol and euthanized at 39 weeks. Structural and compositional alterations in joint tissues were evaluated in vivo using serial radiographs, synovial biopsies, and synovial fluid samples. Joint function was monitored by quantitative gait analysis. Macroscopic, microscopic, and biomechanical evaluation of the cartilage and assessment of subchondral bone parameters were performed ex vivo. Grooved cartilage showed higher OARSI microscopy scores than the contra-lateral sham-operated controls (p < 0.0001). Blunt-grooved cartilage scored higher than sharp-grooved cartilage (p = 0.007) and fixed charge density around these grooves was lower (p = 0.006). Equilibrium and instantaneous moduli trended lower in grooved cartilage than their controls (significant for radiocarpal joints). Changes in other tissues included a threefold to sevenfold change in interleukin-6 expression in synovium from grooved joints at week 23 (p = 0.042) and an increased CPII/C2C ratio in synovial fluid extracted from blunt-grooved joints at week 35 (p = 0.010). Gait analysis outcome revealed mild, gradually increasing lameness. In conclusion, blunt and, to a lesser extent, sharp grooves in combination with a period of moderate exercise, lead to mild degeneration in equine carpal cartilage over a 9-month period, but the effect on overall joint health remains limited.
Collapse
Affiliation(s)
- Nikae C. R. te Moller
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Ali Mohammadi
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Saskia Plomp
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Filipe M. Serra Bragança
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Martijn Beukers
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Behdad Pouran
- Department of OrthopaedicsUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Isaac O. Afara
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Ervin Nippolainen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | | | - Rami K. Korhonen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Juha Töyräs
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
- Diagnostic Imaging CenterKuopio University HospitalKuopioFinland
- School of Information Technology and Electrical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia
| | - Harold Brommer
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - P. René van Weeren
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| |
Collapse
|
6
|
Bansal S, Peloquin JM, Keah NM, O'Reilly OC, Elliott DM, Mauck RL, Zgonis MH. Structure, function, and defect tolerance with maturation of the radial tie fiber network in the knee meniscus. J Orthop Res 2020; 38:2709-2720. [PMID: 32301519 PMCID: PMC7572531 DOI: 10.1002/jor.24697] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 04/03/2020] [Accepted: 04/11/2020] [Indexed: 02/04/2023]
Abstract
The knee menisci are comprised of two orthogonal collagenous networks-circumferential and radial-that combine to enable efficient load bearing by the tissue in adults. Here, we assessed how the structural and functional characteristics of these networks developed over the course of skeletal maturation and determined the role of these fiber networks in defect tolerance with tissue injury. Imaging of the radial tie fiber (RTF) collagen structure in medial bovine menisci from fetal, juvenile, and adult specimens showed increasing heterogeneity, anisotropy, thickness, and density with skeletal development. The mechanical analysis showed that the tensile modulus in the radial direction did not change with skeletal development, though the resilience (in the radial direction) increased and the tolerance to defects in the circumferential direction decreased, in adult compared to fetal tissues. This loss of defect tolerance correlated with increased order in the RTF network in adult tissue. These data provide new insights into the role of the radial fiber network in meniscus function, will lead to improved clinical decision-making in the presence of a tear and may improve engineering efforts to reproduce this critical load-bearing structure in the knee.
Collapse
Affiliation(s)
- Sonia Bansal
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
- Translational Musculoskeletal Research Center, Corporal Michael J Crescenz Veterans Administration Medical Center, Philadelphia, Pennsylvania
| | - John M Peloquin
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware
| | - Niobra M Keah
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Translational Musculoskeletal Research Center, Corporal Michael J Crescenz Veterans Administration Medical Center, Philadelphia, Pennsylvania
| | - Olivia C O'Reilly
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Translational Musculoskeletal Research Center, Corporal Michael J Crescenz Veterans Administration Medical Center, Philadelphia, Pennsylvania
| | - Dawn M Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware
| | - Robert L Mauck
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
- Translational Musculoskeletal Research Center, Corporal Michael J Crescenz Veterans Administration Medical Center, Philadelphia, Pennsylvania
| | - Miltiadis H Zgonis
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Translational Musculoskeletal Research Center, Corporal Michael J Crescenz Veterans Administration Medical Center, Philadelphia, Pennsylvania
| |
Collapse
|
7
|
Drol CJ, Kennedy EB, Hsiung BK, Swift NB, Tan KT. Bioinspirational understanding of flexural performance in hedgehog spines. Acta Biomater 2019; 94:553-564. [PMID: 31129360 DOI: 10.1016/j.actbio.2019.04.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/20/2019] [Accepted: 04/12/2019] [Indexed: 12/01/2022]
Abstract
In this research, the flexural performance of hedgehog spines is investigated in four ways. First, X-ray micro-computed tomography (μCT) is employed to analyze the complex internal architecture of hedgehog spines. μCT images reveal distinct structural morphology, characterized by longitudinal stringers and transverse central plates, which enhance flexural performance. Second, computer-aided design (CAD) is utilized to create and produce different three-dimensional (3D) computational models that gradually approach resemblance to hedgehog spines. Various levels of models are constructed by including and excluding key internal features of hedgehog spines, resulting in the formation of model levels from the simplest to the most realistic form. Third, finite element analysis (FEA) is exploited to simulate flexural behavior of hedgehog spines undergoing three-point bending. FEA results aim to identify and elucidate how internal structural features affect flexural stiffness and bending stress contours. Fourth, flexural analytical modeling is performed to calculate flexural shear flow and twist angle during transverse loading. The effects of the number of hedgehog outer cells, the spine wall thickness ratio and radius ratio are theoretically investigated to predict the shear stress and twist angle of the hedgehog spine structure. Results demonstrate that longitudinal stringers of the hedgehog spine significantly increase the overall flexural stiffness, while the transverse central plates provide support and rigidity to prevent spines from buckling and collapsing. Interestingly, the 3D model level that most realistically resembles the actual hedgehog spine is evidenced to have the highest specific bending stiffness, demonstrating nature's most efficient design. The findings of this study may be useful for developing hedgehog-inspired lightweight, high-stiffness, impact-tolerant structures. STATEMENT OF SIGNIFICANCE: This research has given much needed insight on the inner morphology of hedgehog spines and the structure-property relationship to the spine's flexural performance. X-ray μCT images reveal inner structural morphology, characterized by longitudinal stringers and transverse plates. Finite element analysis shows that longitudinal stringers significantly increase flexural stiffness, while the transverse plates provide support and rigidity to prevent buckling. The model that resembles the actual hedgehog spine is evidenced to have the highest specific bending stiffness, demonstrating nature's most efficient design. Analytical model studies influence on cell number, spine geometrical ratios, and further confirms nature's perfect design with lowest flexural shear flow and twist angle during transverse loading. This work paths future design for hedgehog-inspired lightweight, high-stiffness, impact-tolerant structures.
Collapse
Affiliation(s)
- Christopher J Drol
- Department of Mechanical Engineering, The University of Akron, Akron, OH 44325, USA
| | - Emily B Kennedy
- Department of Biology, Integrated Bioscience PhD Program, The University of Akron, Akron, OH 44325, USA
| | - Bor-Kai Hsiung
- Department of Biology, Integrated Bioscience PhD Program, The University of Akron, Akron, OH 44325, USA
| | - Nathan B Swift
- Department of Physics, Science Technology Entrepreneurship Master's Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kwek-Tze Tan
- Department of Mechanical Engineering, The University of Akron, Akron, OH 44325, USA.
| |
Collapse
|
8
|
Peloquin JM, Santare MH, Elliott DM. Short cracks in knee meniscus tissue cause strain concentrations, but do not reduce ultimate stress, in single-cycle uniaxial tension. ROYAL SOCIETY OPEN SCIENCE 2018; 5:181166. [PMID: 30564409 PMCID: PMC6281910 DOI: 10.1098/rsos.181166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/19/2018] [Indexed: 05/15/2023]
Abstract
Tears are central to knee meniscus pathology and, from a mechanical perspective, are crack-like defects (cracks). In many materials, cracks create stress concentrations that cause progressive local rupture and reduce effective strength. It is currently unknown if cracks in meniscus have these consequences; if they do, this would have repercussions for management of meniscus pathology. The objective of this study was to determine if a short crack in meniscus tissue, which mimics a preclinical meniscus tear, (a) causes crack growth and reduces effective strength, (b) creates a near-tip strain concentration and (c) creates unloaded regions on either side of the crack. Specimens with and without cracks were tested in uniaxial tension and compared in terms of macroscopic stress-strain curves and digital image correlation strain fields. The strain fields were used as an indicator of stress concentrations and unloaded regions. Effective strength was found to be insensitive to the presence of a crack (potential effect < 0.86 s.d.; β = 0.2), but significant strain concentrations, which have the potential to lead to long-term accumulation of tissue or cell damage, were observed near the crack tip.
Collapse
Affiliation(s)
- John M. Peloquin
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA
| | - Michael H. Santare
- Department of Mechanical Engineering, University of Delaware, Newark, DE, USA
| | - Dawn M. Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA
| |
Collapse
|
9
|
Orozco GA, Tanska P, Florea C, Grodzinsky AJ, Korhonen RK. A novel mechanobiological model can predict how physiologically relevant dynamic loading causes proteoglycan loss in mechanically injured articular cartilage. Sci Rep 2018; 8:15599. [PMID: 30348953 PMCID: PMC6197240 DOI: 10.1038/s41598-018-33759-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/02/2018] [Indexed: 12/13/2022] Open
Abstract
Cartilage provides low-friction properties and plays an essential role in diarthrodial joints. A hydrated ground substance composed mainly of proteoglycans (PGs) and a fibrillar collagen network are the main constituents of cartilage. Unfortunately, traumatic joint loading can destroy this complex structure and produce lesions in tissue, leading later to changes in tissue composition and, ultimately, to post-traumatic osteoarthritis (PTOA). Consequently, the fixed charge density (FCD) of PGs may decrease near the lesion. However, the underlying mechanisms leading to these tissue changes are unknown. Here, knee cartilage disks from bovine calves were injuriously compressed, followed by a physiologically relevant dynamic compression for twelve days. FCD content at different follow-up time points was assessed using digital densitometry. A novel cartilage degeneration model was developed by implementing deviatoric and maximum shear strain, as well as fluid velocity controlled algorithms to simulate the FCD loss as a function of time. Predicted loss of FCD was quite uniform around the cartilage lesions when the degeneration algorithm was driven by the fluid velocity, while the deviatoric and shear strain driven mechanisms exhibited slightly discontinuous FCD loss around cracks. Our degeneration algorithm predictions fitted well with the FCD content measured from the experiments. The developed model could subsequently be applied for prediction of FCD depletion around different cartilage lesions and for suggesting optimal rehabilitation protocols.
Collapse
Affiliation(s)
- Gustavo A Orozco
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
| | - Petri Tanska
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Cristina Florea
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
- Departments of Biological Engineering, Electrical Engineering and Computer Science and Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alan J Grodzinsky
- Departments of Biological Engineering, Electrical Engineering and Computer Science and Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rami K Korhonen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
10
|
Vergari C, Mansfield JC, Chan D, Clarke A, Meakin JR, Winlove PC. The effects of needle damage on annulus fibrosus micromechanics. Acta Biomater 2017; 63:274-282. [PMID: 28917706 DOI: 10.1016/j.actbio.2017.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/23/2017] [Accepted: 09/13/2017] [Indexed: 01/07/2023]
Abstract
Needle puncture of the intervertebral disc can initiate a mechanical and biochemical cascade leading to disc degeneration. Puncture's mechanical effects have been shown near the puncture site, mechanical effects should be observed far, relative to needle size, from the puncture site, given the disc-wide damage induced by the stab. The aim of this work was to quantify these far-field effects, and to observe the local structural damage provoked by the needle. Strips of cow tail annulus fibrosus underwent two consecutive mechanical loadings to 5% tensile strain; fifteen samples were punctured in a radial direction with a randomly assigned needle between the two loadings (needle gauges between 19 and 23). Ten samples (control group) were not punctured. During loading, the tissue strains were imaged using second harmonic generation microscopy in a <600×800µm region about 4.4mm from the puncture site. After mechanical testing, the puncture site was imaged in 3D. Puncture had no significant effect on annulus elastic modulus. Imaging showed a modest change in the shearing between fibre bundles however, the linear strain between bundles, intra-bundle shear and linear strain were not significantly affected. At the puncture site, detached lumps of tissue were present. These results suggest that the mechanical effects observed in intact discs are due to the depressurization of the disc, rather than the local damage to the annulus. Needle profiles could be designed, aiming at separating fibre bundles rather than cutting through them, to avoid leaving dying tissue behind. STATEMENT OF SIGNIFICANCE Needle puncture of the intervertebral disc can initiate a mechanical and biochemical cascade leading to disc degeneration, but the link between the local damage of the puncture and the disc-wide effects is not well understood. This work aimed at determining the micro-mechanical effects of the puncture far from its site, and to observe the damage induced by the puncture with high resolution imaging. Results show that the puncture had modest effect far from the puncture, but lumps of tissue were left by the needle, detached from the disc; these could cause further damage through friction and inflammation of the surrounding tissues. This suggests that the cascade leading to degeneration is probably driven by a biochemical response rather than disc-wide mechanical effects.
Collapse
|