Achilles tendon structure differs between competitive distance runners and nonrunners despite no clinical signs or symptoms of midsubstance tendinopathy

Achilles tendinopathy affects many running athletes and often leads to chronic pain and functional deficits. Although changes in tendon structure have been linked with tendinopathy, the effects of distance running on tendon structure are not well understood. Therefore, the purpose of this study was to characterize structural differences in the Achilles tendons in healthy young adults and competitive distance runners using quantitative ultrasound analyses. We hypothesized that competitive distance runners with no clinical signs or symptoms of tendinopathy would have quantitative signs of tendon damage, characterized by decreased collagen alignment and echogenicity, in addition to previous reports of thicker tendons. Longitudinal ultrasound images of the right Achilles tendon midsubstance were acquired in competitive distance runners and recreationally active adults. Collagen organization, mean echogenicity, and tendon thickness were quantified using image processing techniques. Clinical assessments confirmed that runners had no signs or symptoms of tendinopathy, and controls were only included if they had no history of Achilles tendon pain or injuries. Runner tendons were 40% less organized, 48% thicker, and 41% less echogenic compared with the control tendons ( P < 0.001). Young adults engaged in competitive distance running have structurally different tendons than recreationally active young adults. NEW & NOTEWORTHY In this study, we quantified the Achilles tendon substructure in distance runners, and a control group of young adults, to determine whether distance running elicits structural adaptations of the tendon. We found that competitive distance runners have structurally compromised Achilles tendons despite not showing any clinical signs or symptoms of tendon injury. These findings suggest that distance running may stimulate structural changes as a protective mechanism against tendon pain and dysfunction.

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Achilles Tendon Structure Differs Between Runners And Non-Runners Despite No Clinical Signs Or Symptoms Of Mid-Substance Tendinopathy

10.1101/290866 ◽

2018 ◽

Cited By ~ 1

Author(s):

Todd J. Hullfish ◽

Kenton L. Hagan ◽

Ellen Casey ◽

Josh R. Baxter

Keyword(s):

Young Adults ◽

Achilles Tendon ◽

Clinical Symptoms ◽

Clinical Signs ◽

Achilles Tendinopathy ◽

Ultrasound Images ◽

Distance Running ◽

Distance Runners ◽

Structural Differences ◽

The Right

AbstractAchilles tendinopathy affects many running athletes and often leads to chronic pain and functional deficits. While changes in tendon structure have been linked with tendinopathy, the effects of distance running on tendon structure is not well understood. Therefore, the purpose of this study was to characterize structural differences in the Achilles tendons in healthy young adults and competitive distance runners using quantitative ultrasound analyses. We hypothesized that competitive distance runners with no clinical signs or symptoms of tendinopathy would have quantitative signs of tendon damage, characterized by decreased collagen alignment and echogenicity, in addition to previous reports of thicker tendons. Longitudinal ultrasound images of the right Achilles tendon mid-substance were acquired in competitive distance runners and recreationally-active adults. Collagen organization, mean echogenicity, and tendon thickness were quantified using image processing techniques. Clinical assessments confirmed that runners had no signs or symptoms of tendinopathy and controls were only included if they had no history of Achilles tendon pain or injuries. Runner tendons were 40% less organized, 48% thicker, and 41% less echogenic compared to the control tendons (p < 0.001). Young adults engaged in competitive distance-running have structurally different tendons than recreationally-active young adults. While these structural differences have been associated with tendon damage, the lack of clinical symptoms of tendinopathy may suggest that these detected differences may either be precursors of tendinopathy development or protective adaptations to cyclic tendon loading experienced during running.

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Tendon Structure Quantified using Ultrasound Imaging Differs Based on Location and Training Type

10.1101/393520 ◽

2018 ◽

Author(s):

Kenton L. Hagan ◽

Todd Hullfish ◽

Ellen Casey ◽

Josh R. Baxter

Keyword(s):

Achilles Tendon ◽

Patellar Tendon ◽

Ultrasound Imaging ◽

Structural Changes ◽

Ultrasound Images ◽

Distance Runners ◽

Cross Sectional ◽

Specific Loading ◽

Cross Country ◽

Tendon Remodeling

AbstractAchilles tendinopathy is ten-times more common amongst running athletes compared to age-matched peers. Load induced tendon remodeling and its progression in an at-risk population of developing symptomatic tendinopathy is not well understood. The purpose of this study was to prospectively characterize Achilles and patellar tendon structure in competitive collegiate distance runners over different competitive seasons using quantitative ultrasound imaging. Twenty-two collegiate cross country runners and eleven controls were examined for this study. Longitudinal and cross-sectional ultrasound images of bilateral Achilles and patellar tendons were obtained at the one week prior to start of formal collegiate cross country practices, one week after the conclusion of cross country season, and one week prior to outdoor track and field championships. Collagen organization, mean echogenicity, tendon thickness, and neovascularity were determined using well established image processing techniques. We found that Achilles and patellar tendons respond differently to high-volume running and transitions from one sport season to another, suggesting that tendon structure is sensitive to differences in tendon loading biomechanics. Our findings indicate that Achilles tendon structure in trained runners differ structurally to control tendons but is stable throughout training while patellar tendon structure changes in response to the transition in training volume between cross country and track seasons. These findings expand upon prior reports that some degree of tendon remodeling may act as a protective adaptation for sport specific loading.News and NoteworthyIn this study we prospectively examined the Achilles and patellar tendon structure of distance runners to determine if continued training through multiple seasons elicits tendon remodeling or pathology. We found that Achilles and patellar tendons respond uniquely to the changing loads required during each season. Achilles tendon collagen alignment is mostly stable throughout the competitive cycle, but the patellar tendon undergoes structural changes following the transition from cross-country to track season.

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The Guanine-Thymine Dinucleotide Repeat Polymorphism within the Tenascin-C Gene is Associated with Achilles Tendon Injuries

The American Journal of Sports Medicine ◽

10.1177/0363546504271986 ◽

2005 ◽

Vol 33 (7) ◽

pp. 1016-1021 ◽

Cited By ~ 114

Author(s):

Gaonyadiwe G. Mokone ◽

Mamta Gajjar ◽

Alison V. September ◽

Martin P. Schwellnus ◽

Jacquie Greenberg ◽

...

Keyword(s):

Achilles Tendon ◽

Tendon Injury ◽

Tendon Injuries ◽

Dinucleotide Repeat ◽

Control Group ◽

Repeat Polymorphism ◽

Physically Active ◽

Tenascin C ◽

Symptomatic Group ◽

Dinucleotide Repeat Polymorphism

Background Although there is a high incidence of tendon injury as a result of participation in physical activity, the mechanisms responsible for such injuries are poorly understood. Investigators have suggested that some people may have a genetic predisposition to develop tendon injuries; in particular, genes on the tip of the long arm of chromosome 9 might, at least in part, be associated with this condition. The tenascin-C gene, which has been mapped to chromosome 9q32-q34, encodes for a structural component of tendons. Hypothesis The tenascin-C gene is associated with Achilles tendon injury. Study Design Case control study; Level of evidence, 3. Methods A total of 114 physically active white subjects with symptoms of Achilles tendon injury and 127 asymptomatic, physically active white control subjects were genotyped for the guanine-thymine dinucleotide repeat polymorphism within the tenascin-C gene. Results A significant difference in the allele frequencies of this polymorphism existed between the 2 groups of subjects (χ2 = 51.0, P =. 001). The frequencies of the alleles containing 12 repeats (symptomatic group, 18.9% vs control group, 10.2%) and 14 repeats (symptomatic group, 9.2% vs control group, 0.8%) were significantly higher in the symptomatic group, while the frequencies of the alleles containing 13 repeats (symptomatic group, 8.8% vs control group, 24.0%) and 17 repeats (symptomatic group, 7.5% vs control group, 20.1%) were significantly lower in this same group. Subjects who were homozygous or heterozygous for the underrepresented alleles (13 and 17 repeats) but who did not possess an overrepresented allele (12 and 14 repeats) may have a lower risk of developing Achilles tendon injuries (odds ratio, 6.2; 95% confidence interval, 3.5-11.0; P <. 001). Conclusions The guanine-thymine dinucleotide repeat polymorphism within the tenascin-C gene is associated with Achilles tendon injury. Alleles containing 12 and 14 guanine-thymine repeats were overrepresented in subjects with tendon injuries, while the alleles containing 13 and 17 repeats were underrepresented. Clinical Relevance Persons who have variants of the tenascin-C gene with 12 and 14 guanine-thymine repeats appear to have a 6-fold risk of developing Achilles tendon injuries.

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Tendon structure quantified using ultrasound imaging differs based on location and training type

Journal of Applied Physiology ◽

10.1152/japplphysiol.00723.2018 ◽

2018 ◽

Vol 125 (6) ◽

pp. 1743-1748 ◽

Cited By ~ 4

Author(s):

Kenton L. Hagan ◽

Todd Hullfish ◽

Ellen Casey ◽

Josh R. Baxter

Keyword(s):

Achilles Tendon ◽

Patellar Tendon ◽

Ultrasound Imaging ◽

Ultrasound Images ◽

Distance Runners ◽

Specific Loading ◽

Cross Country ◽

Collagen Alignment ◽

Tendon Remodeling ◽

Tendon Collagen

Achilles tendinopathy is 10 times more common among running athletes compared with age-matched peers. Load-induced tendon remodeling and its progression in an at-risk population of developing symptomatic tendinopathy are not well understood. The purpose of this study was to prospectively characterize Achilles and patellar tendon structure in competitive collegiate distance runners over different competitive seasons using quantitative ultrasound imaging. Twenty-two collegiate cross-country runners and eleven controls were examined for this study. Ultrasound images of bilateral Achilles and patellar tendons were obtained near the start and end of the collegiate cross-country season and the conclusion outdoor track season. Collagen organization, mean echogenicity, tendon thickness, and neovascularity were determined using well-established image processing techniques. Achilles tendon collagen was less aligned in runners compared with controls (28% greater) but improved slightly (7% decrease) after the completion of the track season. Conversely, patellar tendons in runners were similar to control tendons throughout the cross-country season but underwent collagen alignment (17% decrease) and tendon hypertrophy (21% increase). Our findings indicate that Achilles tendon structure in trained runners differs structurally from control tendons but is stable throughout training while patellar tendon structure changes in response to the transition in training volume between cross-country and track seasons. These findings expand upon prior reports that some degree of tendon remodeling may act as a protective adaptation for sport specific loading. NEW & NOTEWORTHY In this study we prospectively examined the Achilles and patellar tendon structure of distance runners to determine if continued training through multiple seasons elicits tendon remodeling or pathology. We found that Achilles and patellar tendons respond uniquely to the changing loads required during each season. Achilles tendon collagen alignment is mostly stable throughout the competitive cycle, but the patellar tendon structurally remodels following the transition from cross-country to track season.

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Antioxidant properties of Artemisia absinthium accelerate healing of experimental Achilles tendon injury in rabbits

Herba Polonica ◽

10.2478/hepo-2018-0003 ◽

2018 ◽

Vol 64 (1) ◽

pp. 36-43

Author(s):

Ali Hoseinian ◽

Hamid Reza Moslemi ◽

Reza Sedaghat

Keyword(s):

Achilles Tendon ◽

Healing Rate ◽

Healing Process ◽

Antioxidant Properties ◽

Tendon Repair ◽

Treated Group ◽

Tendon Injury ◽

Control Group ◽

Artemisia Absinthium ◽

And Control

Summary Introduction: Delayed tendon healing is still found to be among the complications that occur most often after tendon repair. Objective: The role of local injection of Artemisia absinthium was evaluated in healing of experimental Achilles tendon injury in rabbits. Methods:. In nine adult New Zealand rabbits a partial thickness tenotomy was created on both hindlimbs. A. absinthium extract and normal saline were respectively injected daily to treatment and control groups for three days. Results: On the day 7 after injury, the tendon sections showed that healing rate in A. absinthium treated group was higher than that in control group. Furthermore, at days 14 and 28, comparison between A. absinthium treated group and control group demonstrated that A. absinthium increased the healing rate but with no significance. Conclusions: Results of this study have showed that application of A. absinthium extract can improve healing process of damaged Achilles tendon.

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Treatment of adhesions after Achilles tendon injury using focused ultrasound with targeted bFGF plasmid-loaded cationic microbubbles

Open Chemistry ◽

10.1515/chem-2020-0110 ◽

2020 ◽

Vol 18 (1) ◽

pp. 608-619

Author(s):

Yuzhou Shen ◽

Jiancheng Ma ◽

Junsheng Jiang ◽

Zhilin Chen ◽

Wenzhu Yan ◽

...

Keyword(s):

Gene Therapy ◽

Achilles Tendon ◽

Umbilical Vein ◽

Tendon Sheath ◽

Tendon Injury ◽

Tendon Injuries ◽

Intercellular Adhesion Molecule ◽

Control Group ◽

Intercellular Adhesion Molecule 1 ◽

Necrosis Factor Alpha

AbstractNonviral targeting technology has become promising as a form of gene therapy for diseases and injuries, such as Achilles tendon injuries. In this study, we used avidin–biotin bridge and positive–negative charge attractions to load the intercellular adhesion molecule-1 (ICAM-1) antibody and the basic fibroblast growth factor (bFGF) plasmid onto the surface of the microbubbles. The saturated loading capacity for 1.1 × 108 microbubble was 6.55 ± 0.53 µg. We established the ICAM-1 antigen microenvironment using tumor necrosis factor-alpha-stimulated human umbilical vein endothelial cells and found the targeting ability of the prepared microbubbles in vitro. In vivo, we also found that the injected targeted bFGF gene microbubbles expressed the bFGF gene better when compared with that of the control group. Furthermore, we evaluated adhesions after Achilles tendon injuries in rabbits using hematoxylin and eosin and immunohistochemical (IHC) staining methods. The collagen fibers were properly arranged in the tendon, and there was greater cellularity inside the tendon sheath and a clearer boundary between the internal and external tendon sheath than that of the control group. IHC staining showed greater ICAM-1 expression inside the tendon sheath when compared with outside the tendon sheath. In conclusion, targeted microbubbles can be a useful carrier of genes to provide gene therapy for the prevention of adhesions after tendon injury.

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Maximal bite force in young adults with temporomandibular disorders and bruxism

Brazilian Oral Research ◽

10.1590/s1806-83242007000300015 ◽

2007 ◽

Vol 21 (3) ◽

pp. 278-283 ◽

Cited By ~ 35

Author(s):

Raquel Aparecida Pizolato ◽

Maria Beatriz Duarte Gavião ◽

Giédre Berretin-Felix ◽

Ana Claudia Martins Sampaio ◽

Alceu Sergio Trindade Junior

Keyword(s):

Young Adults ◽

Temporomandibular Disorders ◽

Influencing Factor ◽

Clinical Signs ◽

Signs And Symptoms ◽

Bite Force ◽

Control Group ◽

Exact Test ◽

Waking Up ◽

Structured Questionnaire

Parafunctional habits, such as bruxism, are contributory factors for temporomandibular disorders (TMD). The aim of this study was to evaluate the maximal bite force (MBF) in the presence of TMD and bruxism (TMDB) in young adults. Twelve women (mean age 21.5 years) and 7 men (mean age 22.4 years), composed the TMDB group. Ten healthy women and 9 men (mean age 21.4 and 22.4 years, respectively) formed the control group. TMD symptoms were evaluated by a structured questionnaire and clinical signs/symptoms were evaluated during clinical examination. A visual analogical scale (VAS) was applied for stress assessment. MBF was measured with a gnatodynamometer. The subjects were asked to bite 2 times with maximal effort, during 5 seconds, with a rest interval of about one minute. The highest values were considered. The data were analyzed with Shapiro-Wilks W-test, descriptive statistics, paired or unpaired t tests or Mann-Whitney tests when indicated, and Fisher's exact test (p < 0.05). TMDB women presented lower values of MBF as compared to those presented by TMDB men and by the control group. MBF for TMDB men was similar to that of the control group. The proportion of TMDB women with muscle pain and facial/teeth/head pain upon waking up was significantly higher than that of men. Control women presented significantly lower stress scores than the others. It was concluded that MBF was reduced in TMDB women, as they presented more signs and symptoms. Men presented higher MBF values than women, but TMD and bruxism did not significantly decrease MBF. Stress was not an influencing factor for TMD and bruxism in men.

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MAGNETIC RESONANCE IMAGING PERFUSION TECHNIQUE IN THE EVALUATION OF ACHILLES TENDON INJURY IN RABBITS

Acta Ortopédica Brasileira ◽

10.1590/1413-785220192701132230 ◽

2019 ◽

Vol 27 (1) ◽

pp. 12-15

Author(s):

Wilson Campos Tavares Junior ◽

Eduardo Paulino ◽

Maria Angélica Baron Magalhaes ◽

Ana Clara Guimarães Gabrich Fonseca ◽

João Bernardo Sancio Rocha Rodrigues ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Achilles Tendon ◽

White Male ◽

Tendon Injury ◽

Control Group ◽

Resonance Imaging ◽

Dce Mri ◽

Dynamic Contrast Enhanced ◽

Contrast Enhanced

ABSTRACT Objective: This study aimed to evaluate the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the experimental model of Achilles tendon injury. Methods: Twelve white male adults New Zealand rabbits were divided into two groups, a group with resection of the central portion of the Achilles tendon (n = 8) and a control group (n = 4). Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed 4 weeks after the surgical procedure, followed by histological analysis of the tendons. Results: The main finding of this study was the difference (p < 0.001) in peak contrast enhancement on DCE-MRI, which demonstrated that the operated group had greater contrast uptake. The operated tendons showed histological disruption of their architecture, and cluttered appearance of tendinous fibers, with vascular and fibroblast proliferations. Conclusion: DCE-MRI is a technique with a potential to demonstrate changes in the vascularity pattern of the Achilles tendon before and after operation. DCE-MRI has a potential to be used in studies of tendinosis diagnosis and surgical follow-up. Level of evidence II, Experimental Study.

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A comparative study of using Kessler Suture Pattern versus Polypropylene meshes implantation to repair Tenotomized Achilles tendon in bucks

The Iraqi Journal of Veterinary Medicine ◽

10.30539/iraqijvm.v42i1.33 ◽

2018 ◽

Vol 42 (1) ◽

pp. 65-71

Author(s):

Rahi Nahi Al-Asadi

Keyword(s):

Achilles Tendon ◽

Mononuclear Cells ◽

Clinical Signs ◽

Normal Structure ◽

Suture Technique ◽

Lower Percentage ◽

Control Group ◽

Microscopical Examination ◽

Suture Materials ◽

Mesh Implantation

The aim of the current study was to compare the efficacy of Kessler suture pattern and polypropylene meshes implantation to repair severed Achilles tendons in bucks. For this purpos 16 local adult bucks, weighing 30-35kg were used and equally distributed into two groups, the first group: (control group) and the second group (mesh group). Animals were sedated with xylazine 2% and anesthetized locally with lidocaine hydrochloride 2% infiltrated subcutaneously. Skin incision approximately 5 cm. in length was made over the Achilles tendon. The tendon was isolated by blunt dissection from the underlying tissue, then the left Achilles tendon was transected in its mid portion. In the control group, tenorrhaphy of Achilles tendons were immediately performed by using Kessler suture technique using (polypropylene No. 1). In the second group, a polypropylene mesh was wrapped around the cut ends and fixed to the tendon by simple interrupted stitches of polypropylene thread (No.1). Then skin was sutured by interrupted horizontal mattress using silk No.1. Finally plaster of Paris with window was applied. The skin stitches were removed after 10 days. The clinical signs of all animals showed severe lameness during the first three weeks with no significant differences between the two groups. Lameness reflected significant differences (P<0.05) between groups with the progress of postoperative duration (i.e., starting from 4th week). Rapid absence of lameness was more observed in second group (at 4th week) than in first group (at 6th week). At two months post-operative, a higher percentage (100%) was recorded in first group. While a lower percentage (25%) was showed in the second group. Microscopical examination at two month post-suturing revealed proliferation of fibrous connective tissue around suture materials infiltrated by inflammatory cells, in addition to necrotic tissue attachment to the tendon. In mesh implantation and at the same time there were granulations tissues surrounding the narrow mesh holes with tendon fibers expressed proliferation of tenocytes. At four months, first group revealed few blood vessels, and thickened collagen fibers with mononuclear cells infiltration in cut tendon fibers. In mesh implantation the tendon was retained to its nearly normal structure with few (MNCs) in epitenon. It seemed that both groups gave best outcome in healing of operated tendons with superiority of the second group in comparison with the first group.

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Three-dimensional deformation and transverse rotation of the human free Achilles tendon in vivo during isometric plantarflexion contraction

Journal of Applied Physiology ◽

10.1152/japplphysiol.01249.2013 ◽

2014 ◽

Vol 116 (4) ◽

pp. 376-384 ◽

Cited By ~ 29

Author(s):

Steven J. Obst ◽

Jean-Baptiste Renault ◽

Richard Newsham-West ◽

Rod S. Barrett

Keyword(s):

Achilles Tendon ◽

Three Dimensional ◽

Tendon Injury ◽

Ultrasound Images ◽

Maximal Voluntary Isometric Contraction ◽

Cross Sectional ◽

Tendon Length ◽

Transverse Rotation ◽

Transverse Strains

Freehand three-dimensional ultrasound (3DUS) was used to investigate longitudinal and biaxial transverse deformation and rotation of the free Achilles tendon in vivo during a voluntary submaximal isometric muscle contraction. Participants ( n = 8) were scanned at rest and during a 70% maximal voluntary isometric contraction (MVIC) of the plantarflexors. Ultrasound images were manually digitized to render a 3D reconstruction of the free Achilles tendon for the computation of tendon length, volume, cross-sectional area (CSA), mediolateral diameter (MLD), anteroposterior diameter (APD), and transverse rotation. Tendon longitudinal and transverse (CSA, APD, and MLD) deformation and strain at 70% MVIC were calculated relative to the resting condition. There was a significant main effect of contraction on tendon length and mean CSA, MLD, and APD ( P < 0.05), but no effect on tendon volume ( P = 0.70). Group mean transverse strains for CSA, MLD, and APD averaged over the length of the tendon were −5.5%, −8.7% and 8.7%, respectively. Peak CSA, MLD, and APD transverse strains all occurred between 40% and 60% of tendon length. Transverse rotation of the free tendon was negligible at rest but increased under load, becoming externally rotated relative to the calcaneal insertion. The relationship between longitudinal and transverse strains of the free Achilles tendon during muscle-induced elongation may be indicative of interfascicle reorganization. The finding that transverse rotation and strain peaked in midportion of the free Achilles tendon may have important implications for tendon injury mechanisms and estimation of tendon stress in vivo.

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