Honors Project--Smith College, Northampton, Mass., 2010. / Includes bibliographical references (p. 43-46)

Resumo: Há dúvidas em relação à melhor localização da sutura no reparo da lesão do tendão flexor dos dedos da mão, uma vez que o ponto central colocado na região dorsal vascularizada, apesar de gerar maior resistência que o ponto na região palmar, poderia, entretanto, interferir no suprimento sangüíneo do tendão. O objetivo da presente investigação foi avaliar, por meio da biomecânica e histopatologia, o efeito da sutura central na região de tendão normal vascularizada e na região de tendão fibrocartilaginoso avascular, no processo de cicatrização do tendão flexor profundo dos dedos do pé do coelho. Foram estudados 83 coelhos submetidos à sutura central tipo Kessler na região de tendão normal (grupo TN) e na região de tendão fibrocartilaginoso (grupo FC), completada com sutura periférica circunferêncial contínua. Após a cirurgia, o membro operado foi imobilizado pelo período de três semanas. Os animais foram sacrificados no período imediato, duas, três e seis semanas de pós-operatório. Concluiu-se que a colocação da sutura central na região de tendão normal vascularizada ou fibrocartilaginosa avascular não apresenta diferenças em relação aos aspectos biomecânicos e histopatológicos na cicatrização do tendão flexor profundo dos dedos do pé do coelho. / Abstract: There are doubts concerning the best place for suture in repairing the lesion at flexor tendon of fingers. Although the core suture at vascular dorsal region generates more resistance than at palm region it may however interfere in tendon blood supply. The objective of the present research was to evaluate through biomechanics and histopathology the effect of core suture at vascular normal region of tendon as well as at avascular fibrocartilagenous tendon during healing of deep flexor tendon at rabbit toes. Eighty-tree animals were submitted to core Kessler suture at normal tendon region (NT group) as well as at fibrocartilagenous tendon region (FC group) completed with continuous circumferential periphery suture. After surgery the operated extremity was immobilized for a three weeks . The animals were sacrificed immediately and after two, three and six weeks of surgery. It was concluded that core suture at normal or fibrocartilagenous tendon region showed no differences concerning biomechanical and histopathological aspects in healing of deep flexor tendon of rabbit toes. / Orientador: Sérgio Swain Müller / Coorientador: Kunie Iabuki Rabello Coelho / Banca: Hamilton da Rosa Pereira / Banca: Heitor José Rizzardo Ulson / Banca: Rames Mattar Júnior / Banca: Nilton Mazzer / Doutor

No description available.

A utilização do ultra som com a finalidade de acelerar o reparo tecidual é muito freqüente na prática clínica, embora as bases científicas para sua utilização não estejam bem estabelecidas. Este estudo analisou os efeitos do ultra som na cicatrização de tendões flexores de coelhos após tenorrafia. Foram utilizados 30 coelhos da raça Nova Zelândia, com peso médio de 2,7 Kg, divididos em dois grupos de 15 animais submetidos a tenotomia e tenorrafia com sutura tipo Kessler do tendão flexor profundo do terceiro dedo da pata dianteira direita. Após 24 horas foi iniciado em um dos grupos tratamento com ultra som, sendo o outro grupo utilizado para controle. A freqüência utilizada foi a de 3 MHz e a intensidade de 0,8 W/centímetro quadrado (SATA), por contato direto durante 7 dias consecutivos. Cada grupo foi dividido em subgrupos com 5 animais cada, e estes sacrificados em períodos distintos (8, 15 e 30 graus PO), e o tendão operado, dissecado e submetido à análise histológica pela microscopia de luz, analisando a reação inflamatória, grau de necrose, proliferação de fibroblastos, deposição de colágeno e formação de granuloma. Os resultados mostraram que o ultra som interferiu com o processo de reparo tecidual após a tenorrafia dos tendões flexores de coelhos / The use of ultrasound aiming to accelerate tissue healing is very frequent in clinical pratice, although the scientific basis to its use are not well established. This study analized the effects of ultrasound on the healing of rabbit’s flexor tendons after repair. It was used 30 New Zealand rabbits, with an average weight of 2.7 Kg, divided in two groups of 15 animal. They were submetted to tenotomy and repair with Kessler’s suture on deep flexor tendon of the middle right front claw. After 24 hour one of the groups started the ultrasound treatment, and the other was de control group. The ultrasound frequency used was 3 MHz and the intensity was 0.8 W/square cemtimeter (SATA), by direct contact during 7 consecutive days. Each group was divided in subgroups with 5 animals each, and these were killed in distincts periods (PO 8, 15 and 30), and the operated tendon was dissected and submitted to histologic analises by light microscopy, anlaysing the inflammatory reaction, necrosis degree, fibroblasts proliferation, colagen synthesis and granulom formation. The result showed that ultrasound interfere on the tissue healing process after repair on the rabbit’s flexor tendons

<p>Introduction: Diabetes mellitus is a major risk factor for tendon pain, injury, and pathology. Surprisingly, tendon problems persist in diabetic patients with superior blood glucose control (HbA1c<6.5), suggesting that alternative mechanisms contribute to this problem. Advanced glycation end products (AGEs) have been implicated in several diabetes-related complications, but their role in diabetic tendon pathology has not fully been explored. To expand our understanding of AGE-mediated tendon pathology, the following five studies were completed.</p><p>Study 1: Streptozotocin-induced diabetes alters transcription of multiple genes necessary for extracellular matrix remodeling in rat patellar tendon. RNA was isolated from the patellar tendon of non-diabetic (control, n=9), 1-week diabetic (acute, n=8), 10-weeks diabetic (chronic, n=7), and insulin treated 10-weeks diabetic (insulin, n=8) rats. Determination of mRNA transcripts was completed using droplet digital PCR (ddPCR). Our findings indicated that STZ-induced diabetes results in rapid and large changes in the expression of several genes that are key to extracellular matrix (ECM) remodeling, maintenance, and maturation.</p><p>Study 2: Advanced glycation end products suppress mitochondrial function and proliferative capacity of Achilles tendon-derived fibroblasts. Using an <i>in vitro</i> cell culture system, rat Achilles tendon fibroblasts were treated with glycolaldehyde-derived AGEs (0, 50, 100, and 200μg/ml) for 48 hours in normal glucose (5.5mM) and high glucose (25mM) conditions. Our findings demonstrate that tendon fibroblasts treated with AGEs display reduced ATP production, electron transport efficiency, and proliferative capacity. These impairments were coupled with alterations in mitochondrial DNA content and expression of genes associated with ECM remodeling, mitochondrial energy metabolism, and apoptosis.</p><p>Study 3: Descriptive transcriptome analysis of tendon derived fibroblasts following <i>in vitro</i> exposure to advanced glycation end products. Rat Achilles tendon fibroblasts were treated with glycolaldehyde-derived AGEs (200μg/ml) for 48 hours in normal glucose (5.5mM) conditions. Total RNA was isolated and the PolyA⁺library was sequenced. We demonstrate that tendon fibroblasts treated with 200μg/ml of AGEs differentially express 2,159 gene targets compared to fibroblasts treated with an equal amount of bovine serum albumin (BSA)-Control. Our findings suggest that AGEs disrupt the tendon fibroblast transcriptome on a large scale and that these pathways may contribute to the development and progression of diabetic tendinopathy.</p><p>Study 4: Evaluation of tendon healing in a mouse model of elevated serum advanced glycation end products following tendon injury. Mice received daily BSA-Control or AGE-BSA injections (200μg/ml) for two weeks prior to creation of a tendon injury in the central third of both patellar tendons. Animals assigned to an exercise group began a moderate treadmill protocol (13 meters/min, five days/week, five weeks) one week following injury and all animals continued to receive injections until termination. We demonstrated that based on our injection dose and schedule, that serum AGEs are significantly elevated to ~200μg/ml, levels that are typically seen in type II diabetic patients. Additionally, a main effect for AGEs was observed in genes related to cell proliferation (Mybl2), mitochondrial function (Bcs1l), and growth factors (Fgf2). However, moderate treadmill exercise did not alter gene markers, such as Ctgf and Fgf2, which are makers of a tendon healing response. Our findings suggest that AGEs modulate tendon gene expression following patellar tendon injury, with no effect of moderate treadmill exercise.</p><p>Study 5: Serum levels of advanced glycation end products and their relationship to patellar tendon properties in diabetes. Subjects (n=32) from a full spectrum of diabetes status, including no history of diabetes were recruited for a cross-sectional study. A fasted blood sample was collected and magnetic resonance imaging (MRI) of the knee was completed. Both current HbA1c and previous diagnosis was used to stratify collected data. Additionally, a full correlation matrix of all measured variables was created to establish relationships that could be used to predict tendon pathology in diabetes. Our findings demonstrate that diabetes is associated with smaller patellar tendon dimensions, which is in disagreement with the literature. Further, we show that changes to body weight normalized (BWN) tendon cross-sectional area (CSA) occur independent of circulating N^ε-(carboxymethyl)lysine (CML) levels. These new data suggest that alternative mechanisms contributing to tendon pathology in diabetes deserve attention.</p>

Tendons are frequently used for reconstructive surgery. This includes palmaris longus, plantaris, the long extensors of the toes and fingers as well as the flexors of the fingers. The surgeon must base his or her selection of the donor tendon for grafting on what is needed, for example tendon size, length, and width. The most desirable tendons in reconstructive surgery are the palmaris longus and plantaris tendons. These two muscles are also considered to be the easiest tendons to harvest, and therefore they remain the ideal choices for plantaris,or tendon grafts. Apart from what is mentioned in the literature, questions remain such as: which characteristics do the palmaris longus and plantaris muscles possess that make them suitable for use as flaps or grafts in reconstructive surgery and; how can knowledge of the characteristics of these muscles improve reconstructive surgery in South Africa? The palmaris longus and plantaris muscles are indeed subject to variation, whether in the general anatomy, form, attachment, actions and/or prevalence. A statistical significant difference was found between the male and female sample when considering the length of the palmaris longus muscle. When comparing the palmaris longus muscle to the plantaris muscles, it was found that there is a statistical significant difference between them as well. Therefore, although these muscles may look alike, when it comes to the surgical aspect it is suggested that the palmaris longus is used when a wider tendon is preferred and the plantaris muscle when a longer tendon is needed. The prevalence of the palmaris longus and plantaris muscles compared well with studies done on other population groups. No correlation was found between the sex of the cadaver and the prevalence of the palmaris longus and plantaris muscles. In addition it was established that there is no relationship between the prevalence of the palmaris longus and plantaris muscles in the same individual. A possible phylogenetic degenerative trend for the palmaris longus muscle was also examined. After studying various age groups, it was determined that such a trend could not be established for this sample. In conclusion, based on the morphology and prevalence of the palmaris longus and plantaris muscles in a South African population, they are ideal for the use of flaps and/or tendon graft in reconstructive surgery. But it is of utmost importance that the reconstructive surgeon, working on South African patients, remember that both these muscles are subject to variation and not only will it be beneficial to employ proper detection methods to determine the viability of either muscle before considering its suitability in reconstructive surgery but also a sound knowledge of the anatomy of these muscles must be known. AFRIKAANS : Tendons word dikwels gebruik vir rekonstruktiewe chirurgie. Dit sluit die M. palmaris longus en M. plantaris, die lang ekstensors van die tone en vingers, sowel as die fleksors van die vingers in. Die chirurg moet sy of haar keuse van die skenkertendon baseer op dit wat benodig word, byvoorbeeld tendongrootte, ~lengte en ~breedte. Die mees gesogte tendons in rekonstruktiewe chirurgie is dié van M. palmaris longus en M. plantaris. Hierdie twee spiere word ook geag as die maklikste spiere om te oes / bekom, en daarom bly hulle die ideale keuse vir weefselsnitte of tendon-oorplantings. Afgesien van wat in die literatuur beskryf word, bly die volgende vrae onbeantwoord: Watter eienskappe maak M. palmaris longus en M. plantaris geskik vir die gebruik as weefselsnitte of tendon-oorplantings in rekonstruktiewe chirurgie en, hoe kan kennis van hierdie eienskappe van dié spiere, rekonstruktiewe chirurgie in Suid-Afrika verbeter? M. palmaris longus en M. plantaris is inderdaad onderworpe aan variasie van die algemene anatomie, vorm, aanhegtings, aksies en / of aanwesigheid en/of afwesigheid. 'n Statistiese beduidende verskil is gevind tussen die manlike en vroulike steekproef ten opsigte van die lengte van M. palmaris longus. M. palmaris longus is met M. plantaris ook vergelyk en daar was gevind dat daar 'n statisties beduidende verskil tussen hierdie spiere is. Alhoewel hierdie spiere dieselfde lyk, is dit belangrik om in ag te neem dat as dit by die chirurgiese aspekte kom, word daar voorgestel dat M. palmaris longus eerder gebruik moet word wanneer 'n wyer tendon verkies word en M. plantaris gekies moet word wanneer ‘n langer tendon benodig word. Daar is goeie ooreenkoms tussen die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris wanneer hul met studies, wat op die ander bevolkingsgroepe gedoen was, vergelyk word. Geen ooreenkomste was tussen die geslag van die kadawer en die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris gevind nie. Daarbenewens was dit vasgestel dat daar geen verhouding tussen die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris in dieselfde individu is nie. 'n Moontlike filogenetiese degeneratiewe tendens vir M. palmaris longus is ook ondersoek. Na die bestudering van verskillende ouderdomsgroepe, is daar bepaal dat so 'n tendens nie bevestig kon word vir hierdie steekproef nie. Ter afsluiting, die morfologie en die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris, in 'n Suid-Afrikaanse bevolking, is ideaal vir die gebruik van weefselsnitte of tendon-oorplantings in rekonstruktiewe chirurgie. Maar dit is van uiterste belang dat die rekonstruktiewe chirurg, wie met Suid-Afrikaanse pasiënte werk, onthou dat beide hierdie spiere onderworpe is aan variasie. Dit sal dus voordelig wees om behoorlike opsporingsmetodes te gebruik om die vatbaarheid van hierdie spiere in rekonstruktiewe chirurgie vas te stel, maar hy of sy het ook kennis van die anatomie van hierdie spiere, nodig. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Anatomy / unrestricted

archives@tulane.edu / The patellar tendon transmits loads from the quadriceps to the tibia promoting locomotion. The main etiological factor behind patellar tendinopathies is thought to be excessive loading and unloading during athletic activity (Pearson & Hussain, 2014). The extracellular matrix (ECM) composition and fibroblast-like tenocytes dictate tendon’s uniaxial mechanical properties (Kannus, 2000). Following injury, a flood of inflammatory cells and spike in certain gene expressions work together to remove damaged tissue, trigger fibroblast proliferation, and deposit a provisional collagen matrix (Thomopoulos et al., 2015). Despite these processes, healed tendons demonstrate significant functional deficits (Mienaltowski et al., 2016). Moreover decrease in cell migration and fiber alignment with age further hampers healing outcomes(Dunkman et al., 2013). Efforts to restore tendon function are impeded by a lack of understanding of the early healing process, which may be age- and sex-dependent (Fryhofer et al., 2016; Mienaltowski et al., 2016). The tendon healing process can be further understood using an agent-based model (ABM). ABMs simulate individual agents and the interactions between them and their environment. This approach has the advantage of building complexity from the ground up, mimicking the underlying tendon physiology (Conte & Paolucci, 2014). Therefore, the objectives of this study were to 1) formulate a literature based ABM of murine patellar tendon healing with varying initial conditions to recapitulate changes observed with aging, and 2) Conduct simulations to determine whether ABM recapitulated salient features of healing, and to make predictions about healing outcomes. / 1 / Jordan Robinson

Patellar Tendinopathy (PT), commonly called "Jumper's Knee", is a condition resulting from repetitive loading of the patellar tendon that presents as anterior knee pain, which is commonly seen in basketball players due to the maneuvers in the sport. Diagnosis of PT often involves a clinical exam followed by ultrasound images for confirmation of the diagnosis to look for key factors of PT. Clinical assessment of ultrasound images of tendons is subjective and requires a high level of experience for reliable interpretation. Thus, there is a need for objective, quantitative methods to assess tendon abnormalities associated with pathology. Ultrasound image texture analysis has emerged as a reliable technique to augment the utility of conventional US imaging, and has recently been shown to distinguish healthy from abnormal tendon and myofascial tissues. The objective of the present study was to conduct image texture analysis to evaluate patellar tendons of collegiate basketball athletes over two seasons. Under an IRB-approved protocol with informed consent, a total of 33 Division 1 collegiate basketball athletes (16 male, 17 female, age 19.9 +/- 1.4 years) underwent clinical evaluation and ultrasound imaging. Four imaging sessions were collected over the course of two years (pre- and post-season). Participants were imaged using a GE LOGIQ S8 (General Electric, USA) ultrasound machine equipped with ML6-15 linear probe. At each imaging session, power Doppler images were collected in the longitudinal and transverse axis, at the proximal, central, and distal regions of the patellar tendon of both knees. Image texture analysis was performed using a custom MATLAB (Mathworks, USA) program to obtain first order (mean, median, variance, skewness, kurtosis, entropy), second order (contrast, energy, and homogeneity), and blob analysis (blob count, BC, and blob area, BA, for 5%, 25%, 50%, 75%, and 95% thresholding values) texture parameters in each image, based upon borders manually drawn by a single researcher. Statistical analysis was conducted to compare imaging sessions (JMP Pro 16, SAS). P-values <0.05 were considered statistically significant. Quantitative texture parameters are able to distinguish characteristics in patellar tendon ultrasound images to distinguish between anatomic region, gender, dominance and pre- to post- season. The 25% and 75% thresholding percentiles effectively showed characteristics of collagen fibers in the patellar tendon. The abnormal diagnosis does not greatly effect texture parameters, which needs to be investigated with more incorporation of grading criteria distinctions and a larger sample size. / Master of Science / Patellar Tendinopathy (PT) is a knee injury that commonly occurs in basketball players. The recovery for PT is often long and the player can still have knee pain when returning to the sport. Diagnosis of PT requires a high level of expertise to consider the patients history, conduct a physical exam and take ultrasound images to look for factors that indicate patellar tendon is damaged. The difficulty of diagnosing PT calls for an objective method to allow for accuracy in assessing patellar tendons. In order to create a more objective measure of ultrasound images, quantitative texture parameters are explored to understand what the brightness values of each pixel and the proximity of pixels together can convey about the image. The objective of this study is to understand what characteristics of the subject (anatomic region, knee dominance, gender, and time point) texture parameters are able to distinguish in patellar tendon ultrasound images.

The purpose of this thesis was to understand the implications of ultrasound in the assessment of flexor tendon shear to establish its role in carpal tunnel syndrome. An in vitro and in vivo approach was used to examine ultrasound “shear” between the tendon and adjacent tenosynovium. Ultrasound shear is defined by the relative displacement between the tendon and tenosynovium, and has been considered a surrogate measure of tendon shear. However, the mechanical implications of relative displacement are not well understood. In Chapters 2 and 3, an in vitro approach was used to compare ultrasound to direct measurements of tendon displacement and tendon shear. Chapter 2 demonstrated the validity of colour Doppler ultrasonography in the evaluation of tendon displacement. Chapter 3 assessed the relationship between ultrasound shear and mechanical tendon shear using frictional work. We dispelled the notion that ultrasound shear represents tendon shear by showing it only captures the viscoelastic stretch of the tenosynovium in tendon shear; missing surface friction from neighbouring anatomical structures in the carpal tunnel. However, measuring viscoelastic resistance in tendon motion is important for the development of pathological fibrosis and thickening of the tenosynovium, a characteristic finding in carpal tunnel syndrome. In Chapter 4 we further established the clinical utility of ultrasound in vivo by showing ultrasound shear discriminated carpal tunnel syndrome symptomatic individuals from the healthy population. Ultrasound measures progressed with symptoms suggesting an etiological progression of fibrosis and thickening with carpal tunnel syndrome. This thesis concluded that ultrasound only partially represents tendon shear with the viscoelastic component, but underscored the clinical implications. Ultrasound provides a non-invasive assessment of viscoelastic resistance that will be highly valuable for our understanding of the role of wrist and hand motion in the etiology of injury with potential applications in the diagnosis of carpal tunnel syndrome. / Thesis / Master of Science in Kinesiology

In 1998, the United States National Committee on Biomechanics (USNCB) established an evolving discipline called Functional Tissue Engineering (FTE). In establishing this discipline, the goals of the USNCB were to advance FTE by increasing awareness among tissue engineers about the importance of restoring function when engineering tissue constructs. Another goal was to encourage tissue engineers to incorporate these functional criteria in the design, manufacturing and optimization of tissue engineered constructs. Based on this motivation, an investigation of the structure and mechanical properties of the rabbit patellar tendon will be executed, with the ultimate goal of creating a multiscale soft tissue model based on internal state variable (ISV) theory. Many continuum scale models, mostly phenomenological and microstrucutral, have been created to contribute to the understanding of the complex functional properties of the tendon, such as its anisotropy, inhomogeneity, nonlinearity, and viscoelasticity. However, none of these models have represented the mechanical behavior of the tendon in the presence of internal structural change on a multiscale level. The development of a multiscale ISV model will allow the capture of the irreversible, path history dependent aspects of the material behavior. The objective of this study is to contribute to the multiscale ISV model development by quantifying the structure- property relations. In particular, the fibril distribution at the microstructural level and the resultant multiaxial stress states (longitudinal and transverse compression and longitudinal tension) will be examined).