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Böl M, Leichsenring K, Kohn S, Ehret AE. The anisotropic and region-dependent mechanical response of wrap-around tendons under tensile, compressive and combined multiaxial loads. Acta Biomater 2024:S1742-7061(24)00301-5. [PMID: 38838908 DOI: 10.1016/j.actbio.2024.05.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 05/20/2024] [Accepted: 05/30/2024] [Indexed: 06/07/2024]
Abstract
The present work reports on the multiaxial region and orientation-dependent mechanical properties of two porcine wrap-around tendons under tensile, compressive and combined loads based on an extensive study with n=175 samples. The results provide a detailed dataset of the anisotropic tensile and compressive longitudinal properties and document a pronounced tension-compression asymmetry. Motivated by the physiological loading conditions of these tendons, which include transversal compression at bony abutments in addition to longitudinal tension, we systematically investigated the change in axial tension when the tendon is compressed transversally along one or both perpendicular directions. The results reveal that the transversal compression can increase axial tension (proximal-distal direction) in both cases to orders of 30%, yet by a larger amount in the first case (transversal compression in anterior-posterior direction), which seems to be more relevant for wrap-around tendons in-vivo. These quantitative measurements are in line with earlier findings on auxetic properties of tendon tissue, but show for the first time the influence of this property on the stress response of the tendon, and may thus reveal an important functional principle within these essential elements of force transmission in the body. STATEMENT OF SIGNIFICANCE: The work reports for the first time on multiaxial region and orientation-dependent mechanical properties of wrap-around tendons under various loads. The results indicate that differences in the mechanical properties exist between zones that are predominantly in a uniaxial tensile state and those that experience complex load states. The observed counterintuitive increase of the axial tension upon lateral compression points at auxetic properties of the tendon tissue which may be pivotal for the function of the tendon as an element of the musculoskeletal system. It suggests that the tendon's performance in transmitting forces is not diminished but enhanced when the action line is deflected by a bony pulley around which the tendon wraps, representing an important functional principle of tendon tissue.
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Affiliation(s)
- Markus Böl
- Institute of Mechanics and Adaptronics, Technische Universität Braunschweig, Braunschweig D-38106, Germany.
| | - Kay Leichsenring
- Institute of Mechanics and Adaptronics, Technische Universität Braunschweig, Braunschweig D-38106, Germany
| | - Stephan Kohn
- Institute of Mechanics and Adaptronics, Technische Universität Braunschweig, Braunschweig D-38106, Germany
| | - Alexander E Ehret
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland; Institute for Mechanical Systems, ETH Zurich, Zürich, CH-8092, Switzerland
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2
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Chatterjee M, Evans MK, Bell R, Nguyen PK, Kamalitdinov TB, Korntner S, Kuo CK, Dyment NA, Andarawis-Puri N. Histological and immunohistochemical guide to tendon tissue. J Orthop Res 2023; 41:2114-2132. [PMID: 37321983 DOI: 10.1002/jor.25645] [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: 12/01/2022] [Revised: 06/02/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023]
Abstract
Tendons are unique dense connective tissues with discrete zones having specific structure and function. They are juxtaposed with other tissues (e.g., bone, muscle, and fat) with different compositional, structural, and mechanical properties. Additionally, tendon properties change drastically with growth and development, disease, aging, and injury. Consequently, there are unique challenges to performing high quality histological assessment of this tissue. To address this need, histological assessment was one of the breakout session topics at the 2022 Orthopaedic Research Society (ORS) Tendon Conference hosted at the University of Pennsylvania. The purpose of the breakout session was to discuss needs from members of the ORS Tendon Section related to histological procedures, data presentation, knowledge dissemination, and guidelines for future work. Therefore, this review provides a brief overview of the outcomes of this discussion and provides a set of guidelines, based on the perspectives from our laboratories, for histological assessment to assist researchers in their quest to utilize these techniques to enhance the outcomes and interpretations of their studies.
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Affiliation(s)
- Monideepa Chatterjee
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Mary K Evans
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rebecca Bell
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
| | - Phong K Nguyen
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
| | - Timur B Kamalitdinov
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stefanie Korntner
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
| | - Catherine K Kuo
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopaedics, University of Maryland Medical Center, Baltimore, Maryland, USA
| | - Nathaniel A Dyment
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nelly Andarawis-Puri
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
- Hospital for Special Surgery, New York, New York, USA
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3
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Pringels L, Cook JL, Witvrouw E, Burssens A, Vanden Bossche L, Wezenbeek E. Exploring the role of intratendinous pressure in the pathogenesis of tendon pathology: a narrative review and conceptual framework. Br J Sports Med 2023; 57:1042-1048. [PMID: 36323498 PMCID: PMC10423488 DOI: 10.1136/bjsports-2022-106066] [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] [Accepted: 10/13/2022] [Indexed: 02/07/2023]
Abstract
Despite the high prevalence of tendon pathology in athletes, the underlying pathogenesis is still poorly understood. Various aetiological theories have been presented and rejected in the past, but the tendon cell response model still holds true. This model describes how the tendon cell is the key regulator of the extracellular matrix and how pathology is induced by a failed adaptation to a disturbance of tissue homeostasis. Such failure has been attributed to various kinds of stressors (eg, mechanical, thermal and ischaemic), but crucial elements seem to be missing to fully understand the pathogenesis. Importantly, a disturbance of tissue pressure homeostasis has not yet been considered a possible factor, despite it being associated with numerous pathologies. Therefore, we conducted an extensive narrative literature review on the possible role of intratendinous pressure in the pathogenesis of tendon pathology. This review explores the current understanding of pressure dynamics and the role of tissue pressure in the pathogenesis of other disorders with structural similarities to tendons. By bridging these insights with known structural changes that occur in tendon pathology, a conceptual model was constituted. This model provides an overview of the possible mechanism of how an increase in intratendinous pressure might be involved in the development and progression of tendon pathology and contribute to tendon pain. In addition, some therapies that could reduce intratendinous pressure and accelerate tendon healing are proposed. Further experimental research is encouraged to investigate our hypotheses and to initiate debate on the relevance of intratendinous pressure in tendon pathology.
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Affiliation(s)
- Lauren Pringels
- Department of Physical and Rehabilitation Medicine, Ghent University Hospital, Ghent, Belgium
- Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium
| | - Jill L Cook
- La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, Melbourne, Victoria, Australia
| | - Erik Witvrouw
- Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium
| | - Arne Burssens
- Department of Orthopaedic Surgery, Ghent University Hospital, Ghent, Belgium
| | - Luc Vanden Bossche
- Department of Physical and Rehabilitation Medicine, Ghent University Hospital, Ghent, Belgium
- Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium
| | - Evi Wezenbeek
- Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium
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Hedayati R, Yousefi A, Dezaki ML, Bodaghi M. Analytical relationships for 2D Re-entrant auxetic metamaterials: An application to 3D printing flexible implants. J Mech Behav Biomed Mater 2023; 143:105938. [PMID: 37263172 DOI: 10.1016/j.jmbbm.2023.105938] [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: 03/26/2023] [Revised: 05/12/2023] [Accepted: 05/24/2023] [Indexed: 06/03/2023]
Abstract
Both 2D and 3D re-entrant designs are among the well-known prevalent auxetic structures exhibiting negative Poisson's ratio. The present study introduces novel analytical relationships for 2D re-entrant hexagonal honeycombs for both negative and positive ranges of the cell interior angle θ (θ<0 showing a negative Poisson's ratio). The derived analytical solutions are validated against finite element method (FEM) and experimental results. The results show that, compared to the analytical solutions available in the literature, the analytical relationships presented in this study provide the most accurate results for elastic modulus, Poisson's ratio, and yield stress. The analytical/computational tools are then implemented for designing Kinesio taping (KT) structures applicable to treatment of Achilles tendon injuries. One of the main features of the Achilles tendon is a natural auxetic behavior. Poisson's ratio distribution of an Achilles tendon is obtained using longitudinal and transverse strains and are then used to design and 3D print thermoplastic polyurethane (TPU) KT structures with non-uniform distribution of auxetic unit cells. The presented novel KT shows that it is capable of replicating the deformation and global and local Poisson's ratio distributions, similar to those of the Achilles tendon. Due to the absence of similar formulations and procedures in the literature, the results are expected to be instrumental for designing and 3D printing of flexible implants with unusual auxeticity.
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Affiliation(s)
- Reza Hedayati
- Department of Aerospace Materials and Structures (ASM), Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Kluyverweg 1, 2629, HS, Delft, the Netherlands
| | - Armin Yousefi
- Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Mohammadreza Lalegani Dezaki
- Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Mahdi Bodaghi
- Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK.
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Stania M, Pawłowski M, Marszałek W, Juras G, Słomka KJ, Król P. A preliminary investigation into the impact of shock wave therapy and sonotherapy on postural control of stepping tasks in patients with Achilles tendinopathy. Front Neurol 2023; 14:1157335. [PMID: 37332988 PMCID: PMC10272772 DOI: 10.3389/fneur.2023.1157335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/11/2023] [Indexed: 06/20/2023] Open
Abstract
Objective The outcomes of physical therapy are commonly assessed with subjective scales and questionnaires. Hence, a continuous search to identify diagnostic tests that would facilitate objective assessment of symptom reduction in those patients with Achilles tendinopathy who undergo mechanotherapy. The main aim of this study was to evaluate and compare the effectiveness of shock wave and ultrasound treatments, using objective posturographic assessment during step-up and step-down initiation. Materials and methods The patients with non-insertional Achilles tendinopathy and pain lasting for more than 3 months were randomly assigned to one of the experimental groups, i.e., radial shock wave therapy (RSWT), ultrasound therapy, or placebo ultrasound. All groups also received deep friction massage as the primary therapy. The transitional locomotor task was performed with the affected and unaffected limb in random order, on two force platforms under two conditions (step-up and step-down). The recording of center of foot pressure displacements was divided into three phases: quiet standing before step-up/step-down, transit, and quiet standing until measurement completion. Pre-intervention measurements were performed and then short-term follow-ups at weeks 1 and 6 post-therapy. Results The three-way repeated measures ANOVA showed few statistically significant two-factor interactions between therapy type, time point of measurement and the type of the locomotor task. Significant increases in postural sway were observed in the entire study population throughout the follow-up period. Three-way ANOVAs revealed a group effect (shock wave vs. ultrasound) on almost all variables of the quiet standing phase prior to step-up/step-down initiation. Overall, postural stability before the step-up and step-down tasks appeared to be more efficient in patients who had undergone RSWT compared to the ultrasound group. Conclusion Objective posturographic assessment during step-up and step-down initiation did not demonstrate therapeutic superiority of any of the three therapeutic interventions used in patients with non-insertional Achilles tendinopathy.Clinical Trial Registration: The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017).
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Carniel TA, Eckert JP, Atuatti EB, Klahr B, Thiesen JLM, Mentges J, Pinto OT, Müller LG, Fancello EA. Is the fluid volume fraction equal to the water content in tendons? Insights on biphasic modeling. J Mech Behav Biomed Mater 2023; 140:105703. [PMID: 36764169 DOI: 10.1016/j.jmbbm.2023.105703] [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: 11/27/2022] [Revised: 01/12/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023]
Abstract
The mass density of highly hydrated soft tissues is generally assumed to be very close to that of the water, resulting that the fluid mass fraction (water content) being equal to the fluid volume fraction. Within this context, the present study aims to investigate whether such an assumption actually holds for tendon tissues and to what extent it may affect the constitutive characterizations based on biphasic (poroelastic) models. Once the water content was assessed by a classical drying assay, the fluid volume fraction was obtained based on an image segmentation approach. The main achieved results point out that the fluid volume fraction is ∼20% higher than the water content in the studied tendons (flexor digitorum profundus bovine tendons). Based on this, it is shown that the use of the water content instead of the fluid volume fraction may considerably bias the results drawn by biphasic modeling of tendons. Accordingly, a proper measurement of the fluid volume fraction is then required.
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Affiliation(s)
- Thiago André Carniel
- Polytechnic School, Community University of Chapecó Region, Chapecó, SC, Brazil.
| | - João Paulo Eckert
- Polytechnic School, Community University of Chapecó Region, Chapecó, SC, Brazil
| | | | - Bruno Klahr
- Department of Mechanical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | | | - Julia Mentges
- Polytechnic School, Community University of Chapecó Region, Chapecó, SC, Brazil
| | - Otávio Teixeira Pinto
- Department of Mechanical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Liz Girardi Müller
- Graduate Program in Environmental Sciences, Community University of Chapecó Region, Chapecó, SC, Brazil
| | - Eduardo Alberto Fancello
- Department of Mechanical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil; University Hospital, Federal University of Santa Catarina, Florianópolis, SC, Brazil
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7
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Stania M, Juras G, Marszałek W, Król P. Analysis of pain intensity and postural control for assessing the efficacy of shock wave therapy and sonotherapy in Achilles tendinopathy - A randomized controlled trial. Clin Biomech (Bristol, Avon) 2023; 101:105830. [PMID: 36469960 DOI: 10.1016/j.clinbiomech.2022.105830] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/01/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND The troublesome symptoms of Achilles tendinopathy prompt patients to seek effective forms of conservative treatment. The main aim of the study was to determine the therapeutic efficacy of shock wave and ultrasound therapies for Achilles tendinopathy in reducing pain intensity. Treatment efficacy was also assessed using objective posturographic measurements. METHODS Thirty-nine patients patients were randomly allocated to one of three experimental groups that received shock wave therapy (group A), ultrasound therapy (group B) and placebo ultrasound (group C). Posturographic measurements and subjective assessment of pain intensity were taken prior to therapy and at weeks 1 and 6 of therapy completion. FINDINGS A comparison of percentage change in activity-related pain from baseline to 6 weeks post-therapy revealed a significantly greater pain reduction in group A compared to group B. The three-way ANOVA demonstated an effect of treatment type on all posturographic variables. The Bonferroni post-hoc test showed the means of all variables were significantly smaller for group A than group B. Limb condition also had an effect on the center-of-pressure trajectories in anteroposterior plane; the post-hoc test showed the mean values of the variables were significantly greater for the non-affected compared to affected limb. INTERPRETATION Shock wave therapy was significantly more effective than sonotherapy for alleviation of activity-related pain of Achilles tendinopathy. An association was also shown between shock wave therapy and more efficient postural control in patients with Achilles tendinopathy. The parameters of center-of-pressure trajectories in the sagittal plane were significantly greater for the non-affected compared to affected limb. The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017).
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Affiliation(s)
- Magdalena Stania
- Institute of Sport Sciences, Academy of Physical Education, Mikołowska 72a, 40-065 Katowice, Poland.
| | - Grzegorz Juras
- Institute of Sport Sciences, Academy of Physical Education, Mikołowska 72a, 40-065 Katowice, Poland
| | - Wojciech Marszałek
- Institute of Sport Sciences, Academy of Physical Education, Mikołowska 72a, 40-065 Katowice, Poland
| | - Piotr Król
- Institute of Sport Sciences, Academy of Physical Education, Mikołowska 72a, 40-065 Katowice, Poland
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Amlang MH, Luttenberger M, Rammelt S. [Surgical treatment of calcifying insertional Achilles tendinopathy via a lateral approach]. OPERATIVE ORTHOPADIE UND TRAUMATOLOGIE 2022; 34:392-404. [PMID: 36342529 DOI: 10.1007/s00064-022-00787-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/20/2022] [Accepted: 05/05/2022] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Reduction of pain and swelling over the Achilles tendon insertion while maintaining function. INDICATIONS Strong, intolerable pain over the Achilles tendon insertion with chronic, calcifying insertional tendinopathy that does not respond to non-operative treatment over a minimum of 6 months. CONTRAINDICATIONS Chronic wounds or severe circulatory deficits at the foot or ankle, irradiating or projected pain, complex regional pain syndrome (CRPS). SURGICAL TECHNIQUE The intratendinous heel spur is resected via a lateral approach. The superior surface of the calcaneal tuberosity is trimmed by resection of the dorsal heel spur with the oscillating saw. A second osteotomy at the medial edge of the tuberosity extends to the insertion of the plantaris tendon. With the third osteotomy, the Haglund deformity is resected. At the resulting area with cancellous bone, the Achilles tendon is reinserted with a suture anchor. POSTOPERATIVE MANAGEMENT A ventral plastic splint in 20° plantar flexion is worn for a week. Full weight-bearing is allowed in a walking boot with 4 cm heel lift for 6 weeks. The heel lift is then gradually reduced for another 2 weeks. After 8 weeks only an elastic wedge of 1 cm is worn. Physical therapy (isometric exercises) starts in the boot and is intensified after removal of the boot. RESULTS Seven of 12 patients treated with that technique for calcifying insertional Achilles tendinopathy (58%) stated being pain free according to the Likert scale, while the remaining 5 patients (42%) reported a "substantial improvement". The VISA‑A score averaged 84 of 100 points. Postoperative complications have not been observed.
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Affiliation(s)
- Michael H Amlang
- UniversitätsCentrum für Orthopädie, Plastische und Unfallchirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland.
| | - Martin Luttenberger
- UniversitätsCentrum für Orthopädie, Plastische und Unfallchirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland
| | - Stefan Rammelt
- UniversitätsCentrum für Orthopädie, Plastische und Unfallchirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland
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Nguyen PK, Jana A, Huang C, Grafton A, Holt I, Giacomelli M, Kuo CK. Tendon mechanical properties are enhanced via recombinant lysyl oxidase treatment. Front Bioeng Biotechnol 2022; 10:945639. [PMID: 35992359 PMCID: PMC9389157 DOI: 10.3389/fbioe.2022.945639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
Tendon mechanical properties are significantly compromised in adult tendon injuries, tendon-related birth defects, and connective tissue disorders. Unfortunately, there currently is no effective treatment to restore native tendon mechanical properties after postnatal tendon injury or abnormal fetal development. Approaches to promote crosslinking of extracellular matrix components in tendon have been proposed to enhance insufficient mechanical properties of fibrotic tendon after healing. However, these crosslinking agents, which are not naturally present in the body, are associated with toxicity and significant reductions in metabolic activity at concentrations that enhance tendon mechanical properties. In contrast, we propose that an effective method to restore tendon mechanical properties would be to promote lysyl oxidase (LOX)-mediated collagen crosslinking in tendon during adult tissue healing or fetal tissue development. LOX is naturally occurring in the body, and we previously demonstrated LOX-mediated collagen crosslinking to be a critical regulator of tendon mechanical properties during new tissue formation. In this study, we examined the effects of recombinant LOX treatment on tendon at different stages of development. We found that recombinant LOX treatment significantly enhanced tensile and nanoscale tendon mechanical properties without affecting cell viability or collagen content, density, and maturity. Interestingly, both tendon elastic modulus and LOX-mediated collagen crosslink density plateaued at higher recombinant LOX concentrations, which may have been due to limited availability of adjacent lysine residues that are near enough to be crosslinked together. The plateau in crosslink density at higher concentrations of recombinant LOX treatments may have implications for preventing over-stiffening of tendon, though this requires further investigation. These findings demonstrate the exciting potential for a LOX-based therapeutic to enhance tendon mechanical properties via a naturally occurring crosslinking mechanism, which could have tremendous implications for an estimated 32 million acute and chronic tendon and ligament injuries each year in the U.S.
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Affiliation(s)
- Phong K. Nguyen
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States
| | - Aniket Jana
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Chi Huang
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
| | - Alison Grafton
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Iverson Holt
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Michael Giacomelli
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
| | - Catherine K. Kuo
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Catherine K. Kuo,
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10
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Eekhoff JD, Abraham JA, Schott HR, Solon LF, Ulloa GE, Zellers JA, Cannon PC, Lake SP. Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species. Acta Biomater 2022; 163:91-105. [PMID: 35306182 DOI: 10.1016/j.actbio.2022.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/19/2022]
Abstract
Elastin, the main component of elastic fibers, has been demonstrated to significantly influence tendon mechanics using both elastin degradation studies and elastinopathic mouse models. However, it remains unclear how prior results differ between species and functionally distinct tendons and, in particular, how results translate to human tendon. Differences in function between fascicular and interfascicular elastin are also yet to be fully elucidated. Therefore, this study evaluated the quantity, structure, and mechanical contribution of elastin in functionally distinct tendons across species. Tendons with an energy-storing function had slightly more elastin content than tendons with a positional function, and human tendon had at least twice the elastin content of other species. While distinctions in the organization of elastic fibers between fascicles and the interfascicular matrix were observed, differences in structural arrangement of the elastin network between species and tendon type were limited. Mechanical testing paired with enzyme-induced elastin degradation was used to evaluate the contribution of elastin to tendon mechanics. Across all tendons, elastin degradation affected the elastic stress response by decreasing stress values while increasing the modulus gradient of the stress-strain curve. Only the contributions of elastin to viscoelastic properties varied between tendon type and species, with human tendon and energy-storing tendon being more affected. These data suggest that fascicular elastic fibers contribute to the tensile mechanical response of tendon, likely by regulating collagen engagement under load. Results add to prior findings and provide evidence for a more mechanistic understanding of the role of elastic fibers in tendon. STATEMENT OF SIGNIFICANCE: Elastin has previously been shown to influence the mechanical properties of tendon, and degraded or abnormal elastin networks caused by aging or disease may contribute to pain and an increased risk of injury. However, prior work has not fully determined how elastin contributes differently to tendons with varying functional demands, as well as within distinct regions of tendon. This study determined the effects of elastin degradation on the tensile elastic and viscoelastic responses of tendons with varying functional demands, hierarchical structures, and elastin content. Moreover, volumetric imaging and protein quantification were used to thoroughly characterize the elastin network in each distinct tendon. The results presented herein can inform tendon-specific strategies to maintain or restore native properties in elastin-degraded tissue.
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Affiliation(s)
- Jeremy D Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States
| | - James A Abraham
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Hayden R Schott
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Lorenzo F Solon
- Department of Biology, Washington University in St. Louis, United States
| | - Gabriella E Ulloa
- Department of Mechanical Engineering, Massachusetts Institute of Technology, United States
| | - Jennifer A Zellers
- Department of Physical Therapy, Washington University in St. Louis School of Medicine, United States
| | - Paul C Cannon
- Department of Mathematics, Brigham Young University - Idaho, United States
| | - Spencer P Lake
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States; Department of Orthopaedic Surgery, Washington University in St. Louis School of Medicine, , United States.
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11
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Mora KE, Mlawer SJ, Bae AJ, Richards MS, Loiselle AE, Buckley MR. Ultrasound strain mapping of the mouse Achilles tendon during passive dorsiflexion. J Biomech 2022; 132:110920. [PMID: 34998182 PMCID: PMC10564406 DOI: 10.1016/j.jbiomech.2021.110920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/21/2022]
Abstract
Immediately prior to inserting into bone, many healthy tendons experience impingement from nearby bony structures. However, super-physiological levels of impingement are implicated in insertional tendinopathies. Unfortunately, the mechanisms underlying the connection between impingement and tendon pathology remain poorly understood, in part due to the shortage of well-characterized animal models of impingement at clinically relevant sites. As a first step towards developing a model of excessive tendon impingement, the objective of this study was to characterize the mechanical strain environment in the mouse Achilles tendon insertion under passive dorsiflexion and confirm that - like humans - mice experience impingement of the tendon insertion from the calcaneus (heel bone) in dorsiflexed ankle positions. Based on previous work in humans, we hypothesized that during dorsiflexion, the mouse Achilles tendon insertion would experience high levels of transverse compressive strain due to calcaneal impingement. A custom-built loading platform was used to apply passive dorsiflexion, while an ultrasound transducer positioned over the Achilles tendon captured radiofrequency images. A non-rigid image registration algorithm was then used to map the transverse compressive strain based on the acquired ultrasound image sequences. Our results demonstrate that during passive dorsiflexion, transverse compressive strains were produced throughout the Achilles tendon, with significantly larger strain magnitudes at the tendon insertion than at the midsubstance. Furthermore, there was increasing transverse compressive strain observed within the Achilles tendon as a function of increasing dorsiflexion angle. This study enhances our understanding of the unique mechanical loading environment of the Achilles tendon under physiologically relevant conditions.
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Affiliation(s)
- Keshia E Mora
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14620, USA; Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY 14620, USA.
| | - Samuel J Mlawer
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14620, USA; Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY 14620, USA
| | - Albert J Bae
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14620, USA; Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY 14620, USA
| | - Michael S Richards
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY 14623, USA
| | - Alayna E Loiselle
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14620, USA; Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY 14620, USA
| | - Mark R Buckley
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14620, USA; Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY 14620, USA
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12
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Sherlock B, Chen J, Mansfield J, Green E, Winlove C. Biophotonic tools for probing extracellular matrix mechanics. Matrix Biol Plus 2021; 12:100093. [PMID: 34934939 PMCID: PMC8661043 DOI: 10.1016/j.mbplus.2021.100093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/07/2021] [Accepted: 11/11/2021] [Indexed: 12/11/2022] Open
Abstract
The complex, hierarchical and heterogeneous biomechanics of the extracellular matrix (ECM) are central to the health of multicellular organisms. Characterising the distribution, dynamics and above all else origins of ECM biomechanics are challenges that have captivated researchers for decades. Recently, a suite of biophotonics techniques have emerged as powerful new tools to investigate ECM biomechanics. In this mini-review, we discuss how the non-destructive, sub-micron resolution imaging capabilities of Raman spectroscopy and nonlinear microscopy are being used to interrogate the biomechanics of thick, living tissues. These high speed, label-free techniques are implemented during mechanical testing, providing unprecedented insight into the compositional and structural response of the ECM to changes in the mechanical environment.
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Affiliation(s)
- B.E. Sherlock
- College of Medicine and Health, University of Exeter, Exeter EX1 2LU, United Kingdom
| | - J. Chen
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - J.C. Mansfield
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - E. Green
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - C.P. Winlove
- College of Engineering, Mathematical and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom
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13
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Jiang X, Wojtkiewicz M, Patwardhan C, Greer S, Kong Y, Kuss M, Huang X, Liao J, Lu Y, Dudley A, Gundry RL, Fuchs M, Streubel P, Duan B. The effects of maturation and aging on the rotator cuff tendon-to-bone interface. FASEB J 2021; 35:e22066. [PMID: 34822203 DOI: 10.1096/fj.202101484r] [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: 09/17/2021] [Revised: 10/29/2021] [Accepted: 11/10/2021] [Indexed: 12/19/2022]
Abstract
Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area, with a high prevalence for the elderly population, but the underlying reason for this phenomenon is still unknown. The objective of this study is to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging in a mouse model. Four different age groups of mice (newborn, young, adult, and old) were studied. Striking variations of the entheses were observed between the newborn and other matured groups, with collagen content, proteoglycan deposition, collagen fiber dispersion was significantly higher in the newborn group. The compositional and histological features of young, adult, and old groups did not show significant differences, except having increased proteoglycan deposition and thinner collagen fibers at the insertion sites in the old group. Nanoindentation testing showed that the old group had a smaller compressive modulus at the insertion site when compared with other groups. However, tensile mechanical testing reported that the old group demonstrated a significantly higher failure stress when compared with the young and adult groups. The proteomics analysis detected dramatic differences in protein content between newborn and young groups but minor changes among young, adult, and old groups. These results demonstrated: (1) the significant alterations of the enthesis composition and structure occur from the newborn to the young time period; (2) the increased risk of rotator cuff tendon injuries in the elderly population is not solely because of old age alone in the rodent model.
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Affiliation(s)
- Xiping Jiang
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Molecular Genetics and Cell Biology Program, Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Melinda Wojtkiewicz
- CardiOmics Program, Center for Heart and Vascular Research, Division of Cardiovascular Medicine, and Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Chinmay Patwardhan
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas, USA
| | - Sydney Greer
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Molecular Genetics and Cell Biology Program, Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Yunfan Kong
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Mitchell Kuss
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Xi Huang
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Jun Liao
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas, USA
| | - Yongfeng Lu
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Andrew Dudley
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Molecular Genetics and Cell Biology Program, Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Rebekah L Gundry
- CardiOmics Program, Center for Heart and Vascular Research, Division of Cardiovascular Medicine, and Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Matthias Fuchs
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Philipp Streubel
- Department of Orthopedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Bin Duan
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Department of Surgery, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA.,Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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