Tendon Injury

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Louis J Soslowsky - One of the best experts on this subject based on the ideXlab platform.

  • ultrasound evaluation of anti vascular endothelial growth factor induced changes in vascular response following Tendon Injury
    Ultrasound in Medicine and Biology, 2019
    Co-Authors: Corinne N Riggin, Susan M Schultz, Chandra M Sehgal, Louis J Soslowsky
    Abstract:

    While vascular ingrowth is necessary for Tendon healing, hypervascularization following Tendon Injury is not always believed to be beneficial, and there is now evidence showing beneficial results of anti-angiogenic treatments in the context of Tendon healing. However, the dose-dependency of anti-angiogenic-altered vascular response, as well as methods for evaluating these changes in vivo, has not been fully investigated. Therefore, the objective of this study was to evaluate if in vivo ultrasound imaging can detect dose-dependent, anti-angiogenic treatment-induced changes in vascularity in rat Achilles Tendon after Injury. Color Doppler ultrasound revealed an increase in vascularity in a low-dosage group, while photoacoustic imaging demonstrated a decrease in vascularity in mid- and high-dosage groups. Histologic staining supported the decrease in vascularity observed in the mid-dosage group. This study demonstrates dose-dependent vascular alterations from the delivery of an anti-angiogenic factor after Tendon Injury that can be detected through ultrasound imaging methods.

  • quantitative comparison of three rat models of achilles Tendon Injury a multidisciplinary approach
    Journal of Biomechanics, 2019
    Co-Authors: Julianne Huegel, James F Boormanpadgett, Courtney A Nuss, Mary Catherine C Minnig, Peter Y W Chan, Andrew F Kuntz, Erik I Waldorff, Nianli Zhang, James T Ryaby, Louis J Soslowsky
    Abstract:

    The Achilles Tendon, while the strongest and largest Tendon in the body, is frequently injured. Inconclusive evidence exists regarding treatment strategies for both complete tears and partial tears. Well-characterized animal models of Tendon Injury are important for understanding physiological processes of Tendon repair and testing potential therapeutics. Utilizing three distinct models of rat Achilles Tendon Injury, the objective of this study was to define and compare the effects and relative impact on Tendon properties and ankle function of both tear severity (complete tear versus partial tear, both with post-operative immobilization) and immobilization after partial tear (partial tear with versus without immobilization). We hypothesized that a complete tear would cause inferior post-Injury properties compared to a partial tear, and that immediate loading after partial tear would improve post-Injury properties compared to immobilization. All models were reproducible and had distinct effects on measured parameters. Injury severity drastically influenced Tendon healing, with complete tear causing decreased ankle mobility and Tendon mechanics compared to partial tears. One week of plantarflexion immobilization had a strong effect on animals receiving a partial tear. Tendons with partial tears and immobilization failed early during fatigue cycling three weeks post-Injury. Partial tear without immobilization had no effect on ankle range of motion through dorsiflexion at any time point compared to the pre-surgery value, while partial tear with immobilization demonstrated diminished function at all post-Injury time points. All three models of Achilles Injury could be useful for Tendon healing investigations, chosen based on the prospective applications of a potential therapeutic.

  • Tendon mineralization is progressive and associated with deterioration of Tendon biomechanical properties and requires bmp smad signaling in the mouse achilles Tendon Injury model
    Matrix Biology, 2016
    Co-Authors: Louis J Soslowsky, Kairui Zhang, Shuji Asai, Michael W Hast, Min Liu, Yu Usami, Masahiro Iwamoto, Motomi Enomotoiwamoto
    Abstract:

    Ectopic Tendon mineralization can develop following Tendon rupture or trauma surgery. The pathogenesis of ectopic Tendon mineralization and its clinical impact have not been fully elucidated yet. In this study, we utilized a mouse Achilles Tendon Injury model to determine whether ectopic Tendon mineralization alters the biomechanical properties of the Tendon and whether BMP signaling is involved in this condition. A complete transverse incision was made at the midpoint of the right Achilles Tendon in 8-week-old CD1 mice and the gap was left open. Ectopic cartilaginous mass formation was found in the injured Tendon by 4weeks post-surgery and ectopic mineralization was detected at 8 to 10weeks post-surgery. Ectopic mineralization grew over time and volume of the mineralized materials of 25-weeks samples was about 2.5 fold bigger than that of 10-weeks samples, indicating that Injury-induced ectopic Tendon mineralization is progressive. In vitro mechanical testing showed that max force, max stress and mid-substance modulus in the 25-weeks samples were significantly lower than the 10-weeks samples. We observed substantial increases in expression of bone morphogenetic protein family genes in injured Tendons 1week post-surgery. Immunohistochemical analysis showed that phosphorylation of both Smad1 and Smad3 was highly increased in injured Tendons as early as 1week post-Injury and remained high in ectopic chondrogenic lesions 4-weeks post-Injury. Treatment with the BMP receptor kinase inhibitor (LDN193189) significantly inhibited Injury-induced Tendon mineralization. These findings indicate that Injury-induced ectopic Tendon mineralization is progressive, involves BMP signaling and associated with deterioration of Tendon biomechanical properties.

  • development and evaluation of multiple Tendon Injury models in the mouse
    Journal of Biomechanics, 2012
    Co-Authors: David P Beason, Andrew F Kuntz, Jason E Hsu, Kristin S Miller, Louis J Soslowsky
    Abstract:

    The mouse has proven to be an advantageous animal model system in basic science research focused on aiding in development and evaluation of potential treatments; however, the small size of mouse Tendons makes consistent and reproducible Injury models and subsequent biomechanical evaluation challenging for studying Tendon healing. In this study, we investigated the feasibility and reproducibility of multiple mouse Tendon Injury models. Our hypothesis was that incisional (using a blade) and excisional (using a biopsy punch) injuries would result in consistent differences in Tendon material properties. At 16 weeks of age, 17 C57BL/6 mice underwent surgery to create defects in the flexor digitorum longus, Achilles, or patellar Tendon. Each animal received 1-2 full-thickness, central-width incisional or excisional injuries per limb; at least one Tendon per limb remained uninjured. The injuries were distributed such that each Tendon type had comparable numbers of uninjured, incisionally injured, and excisionally injured specimens. Three weeks after Injury, all animals were euthanized and Tendons were harvested for mechanical testing. As hypothesized, differences were detected for all three different Tendon types at three weeks post-Injury. While all models created injuries that produced predictable outcomes, the patellar Tendon model was the most consistent in terms of number and size of significant differences in injured Tendons compared to native properties, as well as in the overall variance in the data. This finding provides support for its use in fundamental Tendon healing studies; however, future work may use any of these models, based on their appropriateness for the specific question under study.

  • biomechanics of Tendon Injury and repair
    Journal of Biomechanics, 2004
    Co-Authors: T Tony W W Lin, Luis Cardenas, Louis J Soslowsky
    Abstract:

    Many clinical and experimental studies have investigated how Tendons repair in response to an Injury. This body of work has led to a greater understanding of Tendon healing mechanisms and subsequently to an improvement in their treatment. In this review paper, characterization of normal and healing Tendons is first covered. In addition, the debate between intrinsic and extrinsic healing is examined, and the cellular and extracellular matrix response following a Tendon Injury is detailed. Next, clinical and experimental Injury and repair methods utilizing animal models are discussed. Animal models have been utilized to study the effect of various activity levels, motions, Injury methods, and Injury locations on Tendon Injury and repair. Finally, current and future treatment modalities for improving Tendon healing, such as tissue engineering, cell therapy, and gene therapy, are reviewed.

Ana Sofia Preto - One of the best experts on this subject based on the ideXlab platform.

  • Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of Tendon Injury
    Insights into Imaging, 2018
    Co-Authors: Rui Prado-costa, João Rebelo, João Monteiro-barroso, Ana Sofia Preto
    Abstract:

    Ultrasound elastography (USE) is a recent technology that has experienced major developments in the past two decades. The assessment of the main mechanical properties of tissues can be made with this technology by characterisation of their response to stress. This article reviews the two major techniques used in musculoskeletal elastography, compression elastography (CE) and shear-wave elastography (SWE), and evaluates the studies published on major electronic databases that use both techniques in the context of Tendon pathology. CE accounts for more studies than SWE. The mechanical properties of Tendons, particularly their stiffness, may be altered in the presence of Tendon Injury. CE and SWE have already been used for the assessment of Achilles Tendons, patellar Tendon, quadriceps Tendon, epicondylar Tendons and rotator cuff Tendons and muscles. Achilles tendinopathy is the most studied Tendon Injury with USE, including the postoperative period after surgical repair of Achilles rupture Tendon. In relation to conventional ultrasound (US), USE potentially increases the sensitivity and diagnostic accuracy in tendinopathy, and can detect pathological changes before they are visible in conventional US imaging. Several technical limitations are recognised, and standardisation is necessary to ensure repeatability and comparability of the results when using these techniques. Still, USE is a promising technique under development and may be used not only to promote an early diagnosis, but also to identify the risk of Injury and to support the evaluation of rehabilitation interventions. KEY POINTS: • USE is used for the assessment of the mechanical properties of tissues, including the Tendons. • USE increases diagnostic performance when coupled to conventional US imaging modalities. • USE will be useful in early diagnosis, tracking outcomes and monitoring treatments of Tendon Injury. • Technical issues and lack of standardisation limits USE use in the assessment of Tendon Injury.

  • ultrasound elastography compression elastography and shear wave elastography in the assessment of Tendon Injury
    Insights Into Imaging, 2018
    Co-Authors: Rui Pradocosta, João Rebelo, Joao Monteirobarroso, Ana Sofia Preto
    Abstract:

    Ultrasound elastography (USE) is a recent technology that has experienced major developments in the past two decades. The assessment of the main mechanical properties of tissues can be made with this technology by characterisation of their response to stress. This article reviews the two major techniques used in musculoskeletal elastography, compression elastography (CE) and shear-wave elastography (SWE), and evaluates the studies published on major electronic databases that use both techniques in the context of Tendon pathology. CE accounts for more studies than SWE. The mechanical properties of Tendons, particularly their stiffness, may be altered in the presence of Tendon Injury. CE and SWE have already been used for the assessment of Achilles Tendons, patellar Tendon, quadriceps Tendon, epicondylar Tendons and rotator cuff Tendons and muscles. Achilles tendinopathy is the most studied Tendon Injury with USE, including the postoperative period after surgical repair of Achilles rupture Tendon. In relation to conventional ultrasound (US), USE potentially increases the sensitivity and diagnostic accuracy in tendinopathy, and can detect pathological changes before they are visible in conventional US imaging. Several technical limitations are recognised, and standardisation is necessary to ensure repeatability and comparability of the results when using these techniques. Still, USE is a promising technique under development and may be used not only to promote an early diagnosis, but also to identify the risk of Injury and to support the evaluation of rehabilitation interventions. • USE is used for the assessment of the mechanical properties of tissues, including the Tendons. • USE increases diagnostic performance when coupled to conventional US imaging modalities. • USE will be useful in early diagnosis, tracking outcomes and monitoring treatments of Tendon Injury. • Technical issues and lack of standardisation limits USE use in the assessment of Tendon Injury.

Kaiming Chan - One of the best experts on this subject based on the ideXlab platform.

  • local administration of trolox a vitamin e analog reduced Tendon adhesion in a chicken model of flexor digitorum profundus Tendon Injury
    Journal of orthopaedic translation, 2017
    Co-Authors: Yukwa Lee, Kaiming Chan, Tsuiyu Mok, Leungkim Hung
    Abstract:

    Summary Background Hand flexor Tendon injuries are compromised with Tendon adhesion. Tendon adhesion forms between flexor Tendon and Tendon sheath, reduces the range of motion of fingers, and affects their function. Oxidative stress is increased in flexor Tendon after Injury and might play a role in Tendon adhesion formation. Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a water-soluble analog of vitamin E, is antioxidative. Trolox reduced oxidative stress and the expression of fibrotic cytokines in the bile gut ligation animal model. Vitamin C and Trolox are strong antioxidants, but they might also have prooxidant properties. The prooxidant properties of vitamin C and Trolox are different. In this study, our aim was to determine the effect of Trolox in reducing Tendon adhesion formation. Methods Flexor digitorum profundus Tendon Injury was induced in 54 Kai-Mei Chicken according to a well-established protocol. After wound closure, an injection of 50 μL saline, 10mM Trolox, or 100mM Trolox was administered into the wound area. At 2 weeks or 6 weeks after the surgery, chicken feet were harvested for gliding test, high-resolution ultrasound measurement on a fibrotic area, and histology. Results At Week 2 after the surgery, Trolox has no effect on the flexion angle and gliding resistance, whereas a significant improvement was observed in the flexion angle and gliding resistance in the Trolox-treated groups at Week 6. However, no dose response was observed. In the ultrasound measurement, there was no significant difference in the fibrotic mass in the Trolox-treated group as compared to the saline group at Week 2. At Week 6, fibrotic mass was significantly reduced in both Trolox-treated groups. From the histological examination, the Trolox-treated groups presented a higher cellularity at Week 2 as compared to the saline group, and reduced fibrosis and adhesion at Week 6. Conclusion Our results suggest that local administration of Trolox can reduce Tendon adhesion, and a higher dose of Trolox did not have negative effects. Clinical Significance Trolox solution might be feasible to reduce Tendon adhesion via intraoperative injection at the wound area during Tendon repair.

  • local vitamin c injection reduced Tendon adhesion in a chicken model of flexor digitorum profundus Tendon Injury
    Journal of Bone and Joint Surgery American Volume, 2013
    Co-Authors: Leungkim Hung, Yukwa Lee, Tsuiyu Mok, Kaiming Chan
    Abstract:

    Background: Adhesion formation is a complication of hand flexor Tendon repair. Normal gliding function of flexor Tendons can be impaired by an excessive fibrotic response, which may be caused by intraoperative and postoperative hemorrhage. As tissue damage and hemorrhage can disturb redox regulation, thereby favoring fibrotic responses, the purpose of this study was to investigate if antioxidants can reduce Tendon adhesion by antagonizing oxidative stress. Methods: Flexor digitorum profundus Tendon Injury was induced in fifty-seven chickens. In twelve chickens, oxidative stress preInjury, immediately after Injury, and two and six weeks postInjury (n = 3 at each time period) was estimated by measuring tissue levels of the reduced form of glutathione (GSH) and oxidized glutathione (glutathione disulfide [GSSG]) in the proximal interphalangeal joint. In the remaining chickens, 50 μL of saline solution or vitamin-C solution (5 or 50 mg/mL) was injected into the wound immediately after closure of the Tendon sheath. Samples were harvested at two weeks (n = 6 in each group) or six weeks (n = 6 in each group) postInjury for a gliding test, ultrasound imaging, and histological examination. Three chickens from each group were killed at two weeks postInjury for GSH and GSSG measurements to evaluate the treatment effects on postoperative oxidative stress. Results: The GSH level was significantly decreased at two and six weeks postInjury, and the GSSG level was significantly increased at six weeks postInjury. Both 5 and 50-mg/mL vitamin C led to higher tissue levels of GSH at two weeks postInjury, as compared with that in the saline solution group, but no significant change in the GSSG level was detected. Chickens with vitamin-C supplementation showed no significant improvement in gliding resistance and no significant reduction of the fibrotic size at two weeks postInjury, but they did show significant improvement in gliding resistance at six weeks postInjury and the 5-mg/mL vitamin-C group showed a significant reduction of the fibrotic size at six weeks. Histological examination showed less peritendinous adhesion in the vitamin-C groups. Conclusions: Our results suggest that local injection of vitamin-C solution can reduce the extent of adhesion of healing Tendons, probably by redox modulation, in a chicken model. Clinical Relevance: It may be feasible to apply vitamin-C solution intraoperatively at the time of Tendon repair to reduce restrictive Tendon adhesion, but additional studies are needed to optimize the dose required.

  • expression of sensory neuropeptides in Tendon is associated with failed healing and activity related Tendon pain in collagenase induced Tendon Injury
    American Journal of Sports Medicine, 2010
    Co-Authors: Pauline Po Yee Lui, Laishan Chan, Kaiming Chan
    Abstract:

    Background: Increase in expression of substance P (SP) and calcitonin gene-related peptide (CGRP) has been reported in clinical samples of tendinopathy.Purpose: To examine the spatial-temporal expression of these neuropeptides as well as their association with activity-related Tendon pain, matrix degeneration, failed healing, and pathologic calcification in an established collagenase-induced Tendon Injury rat model.Study Design: Controlled laboratory study.Methods: Collagenase or saline was injected into the patellar Tendon of rats. At weeks 2, 4, 8, 12, and 16, just before the rats were sacrificed, the double-stance duration of rats was examined by gait analysis method. After sacrifice, the patellar Tendons were harvested for histologic analysis and immunohistochemical staining of SP and CGRP.Results: There was an increase of SP and CGRP immunopositivity in Tendon fibroblasts at week 2. The immunopositive signals decreased at weeks 4 and 8 and were observed in chondrocyte-like cells. At weeks 12 and 16, ...

Nicola Maffulli - One of the best experts on this subject based on the ideXlab platform.

  • combined ascorbic acid and t3 produce better healing compared to bone marrow mesenchymal stem cells in an achilles Tendon Injury rat model a proof of concept study
    Journal of Orthopaedic Surgery and Research, 2019
    Co-Authors: Francesco Oliva, Nicola Maffulli, Clarissa Gissi, Lucia Calciano, Francesca Veronesi, Milena Fini, Silvia Brogini, Marialucia Gallorini
    Abstract:

    This pilot study aimed to ascertain whether the local application of ascorbic acid (AA), of T3, and of rat (r) bone marrow mesenchymal stem cells (BMSCs), alone or in all possible combinations, promoted healing after an Achilles Tendon Injury in a rat model. An Achilles Tendon defect was produced in 24 6–8-week-old male inbred Lewis rats. The animals were then randomly divided into eight groups of three rats each. The Tendon defect was filled with 50 μL of phosphate-buffered saline (PBS) containing (1) 50 μg/mL AA (AA group), (2) 10−7 M T3 (T3 group), (3) 4 × 106 rBMSCs (rBMSC group), (4) 50 μg/mL AA + 10−7 M T3 (AA + T3 group), (5) 4 × 106 rBMSCs + 50 μg/mL AA (rBMSC + AA group), (6) 4 × 106 rBMSCs + 10−7 M T3 (rBMSC + T3 group), (7) 4 × 106 rBMSCS + 50 μg/mL AA + 10−7 M T3 (rBMSC + AA + T3 group), and (8) PBS only (control group: CTRL). All treatments were administered by local injection immediately after the Tendons had been damaged; additionally, AA was injected also on the second and fourth day from the first injection (for groups 1, 4, 5, and 7), and T3 was injected again every day for 4 days (for groups 2, 4, 6, and 7). At 30 days from initial treatment, Tendon samples were harvested, and the quality of Tendon repair was evaluated using histological and histomorphological analysis. The structure and morphology of the injured Achilles Tendons were evaluated using the modified Svensson, Soslowsky, and Cook score, and the collagen type I and III ratio was calculated. The group treated with AA combined with T3 displayed the lowest Svensson, Soslowsky, and Cook total score value of all tissue sections at histopathological examination, with fiber structure close to regular orientation, normal-like Tendon vasculature, and no cartilage formation. AA + T3 also showed the highest collagen I and the lowest collagen III values compared to all other treatments including the CTRL. There are potential benefits using a combination of AA and T3 to accelerate Tendon healing.

  • tendinopathy and Tendon Injury the future
    Disability and Rehabilitation, 2008
    Co-Authors: Pankaj Sharma, Nicola Maffulli
    Abstract:

    Tendon disorders are debilitating, and difficult to manage. Current management strategies offer symptomatic relief, but do not result in definitive disease resolution. Despite remodeling, the biochemical and mechanical properties of healed Tendon tissue may never match those of intact Tendons. This article presents a detailed up-to-date review of possible strategies for optimizing Tendon healing and repair, such as growth factor therapy, gene therapy, and tissue engineering.

  • biology of Tendon Injury healing modeling and remodeling
    Journal of Musculoskeletal & Neuronal Interactions, 2006
    Co-Authors: P Sharma, Nicola Maffulli
    Abstract:

    Tendon disorders are frequent, and are responsible for much morbidity both in sport and the workplace. Although the presence of degenerative changes does not always lead to symptoms, pre-existing degeneration has been implicated as a risk factor for acute Tendon rupture. The term tendinopathy is a generic descriptor of the clinical conditions in and around Tendons arising from overuse. The terms "tendinosis" and "tendinitis/Tendonitis" should only be used after histopathological examination. Disordered healing is seen in tendinopathy, and inflammation is not typically seen. In acute injuries, the process of Tendon healing is an indivisible process that can be categorized into three overlapping phases for descriptive purposes. Tendon healing can occur intrinsically, via proliferation of epitenon and endotenon tenocytes, or extrinsically, by invasion of cells from the surrounding sheath and synovium. Despite remodeling, the biochemical and mechanical properties of healed Tendon tissue never match those of intact Tendon. Tendon injuries account for considerable morbidity, and often prove disabling for several months, despite what is considered appropriate management. Chronic problems caused by overuse of Tendons probably account for 30% of all running-related injuries, and the prevalence of elbow tendinopathy in tennis players can be as high as 40%. The basic cell biology of Tendons is still not fully understood, and the management of Tendon Injury poses a considerable challenge for clinicians. This article describes the structure of Tendons, and reviews the pathophysiology of Tendon Injury and healing.

  • basic biology of Tendon Injury and healing
    Surgeon-journal of The Royal Colleges of Surgeons of Edinburgh and Ireland, 2005
    Co-Authors: P Sharma, Nicola Maffulli
    Abstract:

    Tendon disorders are commonly seen in clinical practice. Their successful treatment is difficult and patients often experience symptoms for prolonged periods of time. At present the aetiology of Tendon disorders remains unclear, with several factors having been implicated. An improved understanding of Tendon Injury and healing is essential to enable focused treatment strategies to be devised.

Helen L Birch - One of the best experts on this subject based on the ideXlab platform.

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