Les tendons sont des tissus qui réagissent aux stimuli mécaniques externes. Des stimulations mécaniques inadéquates imposées au tendon engendrent des lésions dans le tendon. Plusieurs études ont été réalisées pour comprendre la mécanobiologie des tendons. Celles-ci ne sont malheureusement pas complètes. Le but de ce projet de maîtrise était donc d'approfondir nos connaissances des mécanismes régissant l'évolution du tendon suite à certaines stimulations mécaniques. Précisément, l'objectif de cette maîtrise était de découpler les trois modes d'évolution (l'amélioration, la dégradation mécanique et la dégradation enzymatique de la matrice extracellulaire) pour deux types de chargement: une sous-stimulation et une sur-stimulation mécanique. Pour chacune de ces deux conditions de stimulation, nous avons étudié la variation de l'état du tendon pour trois types de condition de culture du tendon: (1) D-PBS avec inhibiteurs de protéases, (2) milieu de culture avec inhibiteurs de protéases et (3) milieu de culture sans inhibiteurs de protéases. Cela a permis de mettre en lumière les trois modes de d'évolution individuellement. En effet, l'évolution de l'état du tendon peut être approximée par l'équation suivante: évolution = DM - DE + A où DM = dégradation mécanique, DE = dégradation enzymatique et A = amélioration. Avant de pouvoir effectuer ces expériences, nous avons élaboré des protocoles de caractérisation et de stimulation mécanique minutieux. Ces protocoles devaient assurer un contrôle des conditions de culture (ex.: contamination, condition de culture stable,...), des stimulations et des caractérisations mécaniques (ex.: changement du milieu de culture, test de relaxation, test dynamique,...). De cette façon, nous nous assurions que les paramètres de notre expérience n'influençaient pas nos résultats. L'étude, a principalement montré que la contribution relative des trois mécanismes d'évolution diffère selon le type de stimulation imposée.

1. Einleitung Multipotente mesenchymale Stromazellen (MSC) stellen eine interessante Therapieoption in der regenerativen Medizin verschiedener Erkrankungen dar. Aufgrund ihrer Herkunft aus mesodermalem Gewebe ist ihr Einsatz in der Therapie von Sehnenerkrankungen als günstig anzusehen, wo sie bei Pferden bereits erfolgreich verwendet werden. Da dieser Erkrankungskomplex mit degenerativen Veränderungen der Achillessehne des Menschen vergleichbar ist, wäre eine Translation der gewonnenen Ergebnisse in die Humanmedizin wünschenswert. Die zugrunde liegenden Wirkmechanismen bei der Sehnenregeneration sind allerdings bis zum heutigen Tage noch nicht vollständig geklärt. Unter anderem wird eine tenogene Differenzierung der MSC mit nachfolgender Produktion von extrazellulärer Matrix (EZM) diskutiert. Als Nachweis hierfür wird die Genexpression von Matrixproteinen sowie Transkriptionsfaktoren angesehen. Die Isolation von MSC ist aus verschiedenen Geweben möglich; allerdings haben Untersuchungen deutliche Unterschiede in den in-vitro-Charakteristika zwischen den Zellquellen aufgezeigt. Trotz dieser unterschiedlichen Eigenschaften fasst die International Society for Cellular Therapy (ISCT) seit 2006 humane MSC als plastikadhärente Zellen mit tripotentem Differenzierungspotential sowie einem definierten Antigenprofil zusammen. Um eine Vergleichbarkeit equiner und humaner MSC und somit eine bessere Übertragbarkeit gewonnener Erkenntnisse aus der Pferdemedizin zu erreichen, steht aktuell die Untersuchung der geforderten Antigenexpression noch aus. 2. Ziele der Untersuchung In der vorliegenden Arbeit sollte daher erstmalig eine vollständige Charakterisierung des geforderten Antigenprofils equiner MSC aus fünf verschiedenen Quellen durchgeführt werden, um einen Vergleich mit humanen Zellen zu ermöglichen. Zudem sollte eine vergleichende Darstellung der Sehnenmarkerexpression durchgeführt werden, welche das Wissen um die in-vitro-Eigenschaften von MSC erweitern und in Folge zur Auswahl einer optimal für die Therapie von Sehnenerkrankungen geeigneten Zellquelle beitragen soll. 3. Materialien und Methoden In der ersten Studie wurden equine MSC aus Knochenmark, Fettgewebe, Nabelschnurblut, Nabelschnurgewebe und Sehnengewebe bis zur Passage 3 kultiviert und anschließend mittels Durchflusszytometrie auf das Vorkommen der Antigene CD 29, CD 44, CD 73, CD 90 und CD 105 sowie das Fehlen der Antigene CD 14, CD 34, CD 45, CD 79α und MHC II untersucht. In der zweiten Studie wurde eine Genexpressionsanalyse der Sehnenmarker Kollagen 1A2, Kollagen 3A1, Decorin, Tenascin-C und Skleraxis vergleichend mittels Echtzeitpolymerasekettenreaktion an den isolierten Zellen durchgeführt. In beiden Studien wurde eine Probenzahl von n= 6 für jede Zellquelle untersucht. 4. Ergebnisse Keine der untersuchten Zellquellen erfüllte die MSC-Definition der ISCT bezüglich des Antigenprofils. Insbesondere durch den fehlenden Nachweis CD 73 (< 3,07 %) in allen untersuchten Proben unterscheiden sich equine und humane MSC. Die einzigen stabil exprimierten Antigene sind die zusätzlich untersuchten Proteine CD 29 (37,5 % - 65,42 %) und CD 44 (32,2 % - 97,18 %). Das Vorkommen CD 105 konnte in MSC aus Fett- und Sehnengewebe belegt werden. Zusätzlich war ein Nachweis von CD 90 in MSC aus Fettgewebe möglich, welche somit die größte Ähnlichkeit mit der humanen Zellpopulation aufweisen. Die Studie zur Genexpressionsanalyse weist auf eine Basisexpression von Kollagen 1A2, 3A1 und Decorin in MSC aus verschiedenen Quellen hin, welche über der von nativem Sehnengewebe liegt. Auch hier weisen wiederum MSC aus Fettgewebe die höchste Expression auf. 5. Schlussfolgerungen Die vorliegende Arbeit leistet einen Beitrag zu einer vertiefenden in-vitroCharakterisierung equiner MSC. Das Antigenprofil equiner MSC ist nicht vollständig mit dem humaner identisch. Eine abschließende Beurteilung sollte durch Untersuchungen mit spezies-spezifischen Antikörpern erfolgen. Die Ergebnisse der Genexpressionsanalyse unterstützen die Theorie, dass MSC die Sehnenheilung durch Produktion von extrazellulärer Matrix beeinflussen. Der Einsatz von MSC aus Fettgewebe in der Therapie von Sehnenerkrankungen sollte forciert werden, da ihre hohe Sehnenmarkerexpression einen Hinweis auf eine Verbesserung der Sehnenregeneration darstellt.

The tibialis anterior (TA) muscle plays a vital role in human movement such as walking and running. Overuse of TA during these movements leads to an increased susceptibility of injuries e.g. chronic exertional compartment syndrome. TA activation has been shown to be affected by increases in exercise, age, and the external environment (i.e. incline and footwear). Because activation parameters of TA change with condition, it leads to the interpretation that force changes occur too. However,activation is only an approximate indicator of force output of a muscle. Therefore, the overall aim of this thesis was to investigate the parameters affecting accurate measure of TA force, leading to development of a subject-specific EMG-driven model, which takes into consideration specific methodological issues. The first study investigated the reasons why the tendon excursion and geometric method differ so vastly in terms of estimation of TA moment arm. Tendon length changes during the tendon excursion method, and location of the TA line of action and irregularities between talus and foot rotations during the geometric method, were found to affect the accuracy of TA moment arm measurement. A novel, more valid, method was proposed. The second study investigated the errors associated with methods used to account for plantar flexor antagonist co-contraction. A new approach was presented and shown to be, at worse, equivalent to current methods, but allows for accounting throughout the complete range of motion. The final study utilised the outputs from studies one and two to directly measure TA force in vivo. This was used to develop, and validate, an EMG-driven TA force model. Less error was found in the accuracy of estimating TA force when the contractile component length changes were modelled using the ankle, as opposed to the muscle. Overall, these findings increase our understanding of not only the mechanics associated with TA and the ankle, but also improves our ability to accurately monitor these.

Tendon injuries are ubiquitous in the sporting and occupational environment. Clinically they present a challenge to Orthopaedic surgeons as they account for up to half of all sports injuries and almost half of reported work related ailments. The capacity for tendons to heal subsequent to injury is restricted due to their poor blood supply. Moreover, healed tendon tissue may be inferior to the intact tendon, having diminished biochemical and biomechanical properties and this brings about an ever increasing need for optimized treatment methods for tendon repair. Mechanobiology is concerned with how mechanical forces influence physiological and pathological aspects of the living tissue. However, the complex and poorly controlled loading environment in living organisms prevent the establishment of direct relationships between mechanical stimuli and tissue response. By developing a novel in vitro loading system (IVLS), the work in this thesis investigates the potential of a new and exciting biophysical loading intervention, High Frequency Low Magnitude (HFLM) mechanical loading, for stimulation of tendon repair and remodelling. Following a pre-defined stimulation period, healthy rat tail tendon fascicles (RTTFs) were evaluated for tissue viability and metabolism, Glycosaminoglycan (GAG) content, collagen arrangement and tangent modulus, using staining and biochemical assays, together with microscopy techniques, and mechanical testing. HFLM mechanically loaded tendons showed a trend for a higher tangent modulus than fresh tissue, and significantly higher modulus than unloaded. Further, when varying mechanical loading parameters of frequencies and dosages over clinically relevant ranges, a frequency dependent response was observed with increased tangent modulus and GAG content with increasing frequency. An association between high tendon crimp pattern and elevated tendon modulus as a result of HFLM mechanical loading was also demonstrated. Concomitantly, an injury model was developed to evaluate the effects of in vitro static, low frequency cyclic and HFLM mechanical loading conditions on the biochemical and biomechanical properties of in vitro damaged tendons. HFLM mechanically loaded damaged tendons again demonstrated significantly higher modulus and metabolism than unloaded tissue, although these were reduced below those of fresh damaged tissue. The findings in this thesis together with the newly developed IVLS reveal the potential for an exciting and unique biophysical therapeutic loading intervention for treatment of tendon injuries, and provide a scientific platform for further investigation of the effects of HFLM mechanical loads, potentially leading to an application within the clinic for enhanced connective tissue repair and remodelling.

The purpose of the study was to investigate the static and dynamic architecture of supraspinatus throughout its volume in the normal and pathological state. The architecture was first investigated in cadaveric specimens free of any tendon pathology. Using a serial dissection and digitization method tailored for supraspinatus, the musculotendinous architecture was modeled in situ. The 3D model reconstructed in Autodesk MayaTM allowed for visualization and quantification of the fiber bundle architecture i.e. fiber bundle length (FBL), pennation angle (PA), muscle volume (MV) and tendon dimensions. Based on attachment sites and architectural parameters, the supraspinatus was found to have two architecturally distinct regions, anterior and posterior, each with three subdivisions. The findings from the cadaveric investigation served as a map and platform for the development of an ultrasound (US) protocol that allowed for the dynamic fiber bundle architecture to be quantified in vivo in normal subjects and subjects with a full-thickness supraspinatus tendon tear. The architecture was studied in the relaxed state and in three contracted states (60º abduction with either neutral rotation, 80º external rotation, or 80º internal rotation). The dynamic changes in the architecture within the distinct regions of the muscle were not uniform and varied as a function of joint position. Mean FBL in the anterior region shortened significantly with contraction (p<0.05) but not in the posterior. In the anterior region, mean PA was significantly smaller in the middle part compared to the deep (p<0.05). Comparison of the normal and pathological muscle found large differences in the percentage change of FBL and PA with contraction. The architectural parameter that showed the largest changes with tendon pathology was PA. In sum, the results showed that the static and dynamic fiber bundle architecture of supraspinatus is heterogeneous throughout the muscle volume and may influence tendon stresses. The architectural data collected in this study and the 3D muscle model can be used to develop future contractile models. The US protocol may serve as an assessment tool to predict the functional outcome of rehabilitative exercises and surgery.

Thesis questions: • Is the glutaminergic system altered in rotator cuff tendinopathy? • Is the glutaminergic system altered by common treatments? • Are glutaminergic changes related to pain symptoms? • What are the effects of glutamate and glutamate receptor modulation on tendon derived cells? Summary answers: • The glutaminergic system is altered in rotator cuff tendinopathy • Changes within this system are seen after common treatments • Specific glutaminergic changes are associated with the resolution of pain following shoulder surgery but do not predict the severity of pain symptoms • Glutamate has significant effects on tendon derived cells. What is known: It is known that extracellular glutamate concentrations are increased in both Achilles and patellar tendinopathy. It has also been previously shown that the glutamate receptors NMDAR1 and mGluR5 are upregulated in patellar tendinopathy. What this thesis adds: This thesis has shown for the first time that glutamate and NMDAR1 are increased in rotator cuff tendinopathy. Increases in cell proliferation, vascularity and HIF1α are seen after surgical rotator cuff repair and these features are not seen after glucocorticoid injection. There are significant differences between painful and pain-free rotator cuff tendons in terms of glutamate receptor expression (KA1, mGluR7 and mGluR2) and inflammatory cell numbers (CD45 and CD206). Exposure to 1.875mM glutamate for 72 hours results in reduced cell viability, decreased collagen (COL1A1 and COL3A1) and increased aggrecan gene expression; NMDAR antagonism with MK-801 attenuates the deleterious effect on cell viability but had no effect on the changes in matrix gene expression. Bias, confounding and other reasons for caution: The observational histological work was limited by the control tissue. Some control tissue was not age matched, while some of the pain-free control tendons were post-surgical intervention. Confounding factors include tendon structure, length of symptoms and previous treatments. Caution must be applied when discussing the in vivo implications of the in vitro work.

Adult Acquired Flatfoot Deformity (AAFD) is a progressive disease characterized by mechanical degeneration of the soft tissue structure in the arch of the foot that leads to changes in joint alignment. Surgical intervention commonly via tendon transfer and bony osteotomy is used to restore arch architecture, however there is a lack of quantitative assessments that measure the success of the surgical correction in vivo. Using plantar pressures via Tekscan® HR Mat and surveys (SF-36, FAOS), pre-operative and post-operative measures for six participants were defined, analyzed and compared. A paired t-test showed significant lateral shift for percent body weight during walking postoperativelyin the forefoot and midfoot regions. However, arch index measurement showed no significant change. The FAOS survey score also improved statistically postoperatively. The surgical correction was successful as deemed by some of these quantitative and qualitative measures.

This diploma thesis deals with the Achilles tendinopathy, and particularly with its etiopatogenetics. The theoretical part includes information about the Achilles tendon, tendinopathy of Achilles tendon and a summary of dysfunctions of the locomotor system. We assumed that the dysfunction of the locomotor system is the main etiopatogenetic factor of the Achilles tendinopathy, and that it results in changes of its position and loading. In the practical part we tried to reveal these dysfunctions by examination of seven patients, and to prove its main etiopatogenetic influence by a successfull therapy. The aim of the thesis was to point out the importance of the examination as well as the therapy of the locomotor systems function. Powered by TCPDF (www.tcpdf.org)

Title: Flexor tendon pulley lesion as a most frequent injury in sport climbing Specification of the problem: This thesis is focused on the most frequent injury of the hand in sport climbing. It describes the mechanism of the injury and possibilities of conservative and surgical treatment according to the given guidelines in dependence on its relevance. Objectives: The aim of this thesis is the literary review of accessible literary resources from the field of anatomy, kinesiology and biomechanics of the hand and flexor tendon pulley in connection with a sport activity. Furthermore it is aimed on an analysis why is the flexor tendon pulley injury the most frequent injury in sport climbing, and on methods how to treat this injury in the most effective way from the beginning till the return to the full performance based on therapeutic guidelines created by Dr. Schöffl nad Dr. Hochholzer. This thesis should serve as a therapeutic manual for the Czech sport climbers suffering from this type of injury, which is generally very often underestimated and not treated sufficiently. Methods: This diploma thesis has descriptively-analytical character and is structured as a literary review. Keywords: tendon pulley, hand, sport climbing, physiotherapy, conservative treatment

Resumo: Nesta pesquisa foram investigados aspectos anatômicos e biométricos da face flexora dos dígitos de 20 novilhas mestiças da raça Nelore, com idades entre 24 e 36 meses, criadas em sistema extensivo. O material foi proveniente de matadouro sob Fiscalização do Serviço de Inspeção Oficial e mantido sob congelamento a -18°C até o momento da dissecação. Após tricotomia e limpeza das regiões distais ao metacarpo e metatarso, as faces palmar e plantar dos dígitos foram dissecadas in natura e as estruturas anatômicas identificadas e medidas com auxílio de paquímetro universal. As mensurações foram feitas em milímetros (mm) e incluíram o comprimento, a largura e a espessura das estruturas anatômicas digitais. A técnica de dissecação in natura foi considerada útil para a execução deste estudo e as estruturas identificadas e mensuradas incluíram os ligamentos acessórios distais dos paradígitos, ligamentos anulares palmares e plantares, bainha digital tendínea, ligamentos anulares proximais e distais, ligamentos interdigitais distais, tendões flexores digitais superficiais e profundos e a manica flexoria. Os dados biométricos obtidos indicam diferenças (p≤0,05) entre membros, antímeros e dígitos, especialmente nas estruturas anatômicas localizadas distalmente. Devido à escassez de estudos biométricos sobre o assunto, os achados deste trabalho podem servir como valores de referência para a faixa etária de novilhas avaliadas e contribuir em pesquisas morfológicas futuras / Abstract: In the present work anatomic and biometric studies of the distal aspect in the flexor aspect of digits were carried out for 20 cross-breed heifer of Nelore breed aging around 24-36 months raised in an extensive regiment. The materials came from shamble under the Official Fiscalization of Inspect Service and were kept under freezing at -18°C until dissection. After the clipper and cleaning the distal areas, from metacarpus to metatarsus, the structures were dissected and measured by using a universal caliper rule (mm) on length (proximal-distal), widht (abaxial-axial) and thickness (dorso-palmar or dorso-plantar). The dissected structures included the paradigits distal accessories ligaments, palmar and plantar annular ligaments and tendon digital sheath, proximal and distal annular ligaments, interdigital distal ligament, superficial digital flexor tendon and deep digital flexor tendon and manica flexoria. The measured data indicate differences (p≤0,05) among the limb, right, left and respective digits mainly in the more distal analyzed structures. Due to scarcity of biometric studies about this topic, the data found in this work might be useful as a reference for the analyzed group, as well in the anatomic detailed structures which are essential to understanding many of the pathological process of locomotor apparatus in cattle / Orientador: José Wanderley Cattelan / Coorientador: Silvana Martinez Baraldi Artoni / Banca: Julio Carlos Canola / Banca: Claudia Acosta Duarte / Mestre