Degenerative disorders of the rotator cuff tendons account for nearly 75% of all shoulder pain, causing considerable pain and morbidity. Given the strong correlation between age and tendinopathy, and unprecedented population aging, these disorders will become increasingly prevalent. Improved understanding of tendon degeneration will guide the development of future diagnostic and treatments, and is therefore urgently needed. However, the aetiology and pathology of rotator cuff tendinopathy remain unclear. The complicated mechanical environment of the rotator cuff is hypothesised to influence the susceptibility of the tendons to degeneration and tearing. Studies have reported biological adaptations in torn cuff tendons indicative of increased compressive loading within the tendon. The material adaptations of healthy and degenerative cuff tendons are largely unreported but will provide further insight into the role of the mechanical environment in rotator cuff aetiology and pathology. This thesis examined the material adaptations of healthy and diseased tendons to explore the role of mechanical loading in rotator cuff pathology. The material adaptations of healthy animal tendons, and healthy and delaminated human cadaveric rotator cuff tendons, in response to different loading environments were characterised. The effects of age, tears, steroid injection and subacromial decompression surgery on the structural adaptations of human cuff tendons were also studied, as was the effect of tendon cell proliferation on the mechanical properties and degradation behaviour of collagen scaffolds. Loading environment significantly affected the structural adaptations of healthy tendons. Regions exposed to compressive and shear strains exhibited thinner fibres, shorter crimp lengths and thinner, less aligned fibrils compared with regions exposed to tensile strains alone. In healthy rotator cuff tendons, the inhomogeneous loading environment produced topographically inhomogeneous structural adaptations. The tendons of a delaminated rotator cuff exhibited less topographical variation in properties and thinner, less aligned fibrils compared with healthy cuff tendons. Torn cuff tendons exhibited thinner fibrils and shorter crimp lengths compared with control samples. These adaptations were identifiable early in the disease progression, and neither steroid injection nor subacromial decompression surgery significantly influenced these adaptations at seven weeks post‐treatment. Significant correlations between decreasing dimensions and increasing tear size were found when age was included as a confounding factor, reflecting the importance of age and tear size in determining the material properties of tendons. Tendon cell proliferation influenced the mechanical properties and degradation behaviour of the collagen scaffolds, emphasising the integral role of cells in the functional adaptation of biological materials. These results demonstrate the effect of mechanical environment on the material adaptations of tendons. They also indicate the importance of the complicated mechanical environment experienced by the rotator cuff tendons in predisposing the tendons to degeneration and tearing. The observed material adaptations of degenerative and torn tendons suggest that rotator cuff pathology is associated with increased levels of compressive and/or shear strains within the tendon. These changes begin early in the disease progression and neither steroid injection nor sub‐acromial decompression surgery are capable of reversing the changes in the timeframe investigated. These findings highlight the urgent clinical need for pre‐rupture diagnostic techniques for the detection of early pathological changes in the rotator cuff. They also emphasize the requirement for new intervention strategies that restore the healthy mechanical environment and reverse early pathological adaptations in order to prevent catastrophic failure of the tendons.

Chondroplasia, the development of cartilage-like characteristics in tendinous tissue, is a form of degeneration found in tendons including those of the rotator cuff. The molecular mechanism of its development is currently unknown. An examination of the features of the torn rotator cuff and the cartilage literature led to the identification of several potential drivers of chondroplasia including cell shape change/actin cytoskeleton and hypoxia. Lovastatin caused actin cytoskeleton disruption and promoted cartilage matrix deposition in the ATDC5 model. It was the most effective member of a panel of cytoskeletal inhibitors, increasing expression of the chondrocytic markers Sox5 and Sox9 and decreasing expression of COL1A1 and COL3A1 in primary human tenocytes. Its effects were dose dependent, reversible by mevalonate addition and long term treatment induced de novo expression of collagen II. Short term hypoxia upregulated VEGF-A and chondrocytic marker gene DEC1 expression but not other chondrocyte markers. Combination treatment with hypoxia did not enhance the effects of lovastatin. These data suggest that modulation of pathways that regulate the actin cytoskeleton and cell shape may alter tenocyte phenotype.

Title The most often problems in shoulder girdle of women basketball players and options of physiotherapeutic affect. Objectives The main goal of the thesis is in theoretical part to summarize potentional problems in shoulder girdle of basketball players, options and solutions of these problems. There is complex examination of shoulder girdle of dominant upper limb of women basketball players in an experimental part and figure out where is the main problem in this part. Methods There are two parts of the thesis, the first one is the theoretical background for second experimental part where complex functional physiotherapeutic examination of shoulder girdle with using of aspection, palpation and special tests for shoulder girdle were made. The most often problems in shoulder girdle of women basketball player has been determined by using the results of testing process. Results Testing of shoulder girdle of women basketball players showed how often blockage of ribs is. Blockage of fifth rib was present in 90% of the probands, frequent was also decentred position of shoulder and shoulder blade, hypertone of upper fixators of shoulder blade and pectoral muscles. Most of probands had restriction of passive motion to segment in thoracic spine and hypermobility of shoulder. Often was present weakness of...

Universidade de São Paulo, Faculdade de Medicina; 2015. Introdução: Diante de uma rotura traumática do manguito rotador, não há evidência direta que comprove que os reparos realizados precocemente são mais eficazes que aqueles realizados tardiamente. Para abordar essa questão, ensaios biomecânicos e de morfometria óssea foram realizados após roturas extensas do manguito rotador realizadas precocemente (lesões agudas) e tardiamente (lesões crônicas), mediante a utilização de um modelo experimental em ratos. Método: 30 ratos adultos da raça Wistar foram aleatoriamente divididos em três grupos (I, II e III) e submetidos à secção completa dos tendões do supraespinal e infraespinal nos ombros esquerdos. Após oito semanas, nos animais dos grupos I e II, os tendões rotos pertencentes aos ombros esquerdos foram cirurgicamente reparados, e os tendões equivalentes nos ombros direitos foram seccionados e imediatamente reparados. Quatro semanas após os reparos (para os ratos do grupo II) ou oito semanas após os reparos (para os ratos do grupo I), os animais foram submetidos à eutanásia. Os ratos do grupo III foram submetidos à eutanásia oito semanas após a cirurgia de secção tendínea sem que houvesse ocorrido o reparo dos tendões rotos. Os ombros direitos dos animais do grupo III permaneceram intactos e serviram como controles. Após a eutanásia, todos os ratos tiveram seus ombros dissecados e os espécimes foram encaminhados para a realização de testes biomecânicos e de microtomografia computadorizada. Resultados: Para todos os parâmetros biomecânicos analisados, foram encontradas interações significantes referentes aos fatores tempo de cicatrização e reparo, considerando os reparos precoces e tardios. Com relação ao tendão supraespinal para o período de oito semanas de cicatrização, a força máxima até a falha foi significantemente maior nos reparos precoces em comparação aos reparos tardios (31,81 ± 3,86N vs 19,36 ± 6,14N; p < 0,001), bem como a rigidez (17,22 ± 4,35N/mm vs 10,85 ± 4,25N/mm; p=0,034), a tensão máxima até a falha (4,49 ± 2,02N/mm2 vs 1,97 ± 0,61N/mm2; p < 0,001) e o módulo de elasticidade (13,72 ± 5,29N/mm2 vs 6,47 ± 2,42 N/mm2; p=0,033). Com relação ao tendão infraespinal com oito semanas de cicatrização, a força máxima até a falha foi significantemente maior nos reparos precoces em comparação aos reparos tardios (21,26 ± 3,94N vs 12,74 ± 2,87N; p=0,005), assim como a rigidez (12,86 ± 2,65N/mm vs 7,21 ± 3,30N/mm; p=0,014). O grupo com reparo tardio com oito semanas de cicatrização obteve resultados nos testes biomecânicos semelhantes aqueles obtidos nos testes do grupo com lesão sem reparo com oito semanas de cicatrização. A avaliação microtomográfica não apresentou diferenças significantes na microarquitetura óssea entre os reparos realizados precocemente e tardiamente. Conclusões: Os resultados desse estudo demonstram que as roturas extensas do manguito rotador reparadas precocemente produzem um tecido cicatricial na junção ósteo-tendínea com melhores propriedades biomecânicas que as roturas reparadas tardiamente. Porém, ao analisar a morfometria óssea da porção proximal do úmero, verificou-se que os efeitos são equivalentes, tanto para os reparos realizados tardiamente quanto para os reparos realizados precocemente / Introduction: In the event of a traumatic rotator cuff tear, there is no direct evidence that supports early over late surgical repair. To address this knowledge gap, biomechanical and bone morphometry outcomes were assessed following early (acute) and late (chronic) massive rotator cuff tear repairs in an experimental rat model. Methods: 30 adult Wistar rats were randomly divided into three groups (I, II and III), then subjected to combined supraspinatus and infraspinatus tendon tears of the left shoulder. Eight weeks following the injury, animals from groups I and II had the tendons of the injured shoulder surgically repaired. In addition, these animals were subjected to the same injury on the contralateral shoulder, which was immediately repaired. The rats were euthanized four weeks (group II) or eight weeks (group I) following the repairs. Group III was euthanized eight weeks following the injury, without surgical repair of the left shoulder, and the intact right shoulders of this group were used as controls. Tissues from all groups were harvested and subjected to biomechanical testing and bone morphometry analysis. Results: In all biomechanical parameters analyzed, a significant interaction was observed between healing and repair timing. For the supraspinatus tendon with eight weeks healing time, biomechanical properties were significant increased in the early repair group compared to the late repair group, including maximum load to failure (31,81 ± 3,86N vs 19,36 ± 6,14N; p < 0,001), stiffness (17,22 ± 4,35N/mm vs 10,85 ± 4,25N/mm; p=0,034), maximum stress to failure (4,49 ± 2,02N/mm2 vs 1,97 ± 0,61N/mm2; p < 0,001) and modulus of elasticity (13,72 ± 5,29N/mm2 vs 6,47 ± 2,42 N/mm2; p=0,033). For the infraspinatus tendon with eight weeks healing time, biomechanical properties were also significantly increased in the early repair group, including maximum load to failure (21,26 ± 3,94N vs 12,74 ± 2,87N; p=0,005) and stiffness (12,86 ± 2,65N/mm vs 7,21 ± 3,30N/mm; p=0,014). There were no significant differences between the late repair with eight weeks of healing time and the group without surgical repair for supraspinatus and infraspinatus tendons. Concerning bone morphometry of the humeral head, no significant differences were observed when comparing early and late repair groups. Conclusions: The results from this study indicate that early surgical repair of a massive rotator cuff tear leads to increased biomechanical properties of the tissue after healing. However, proximal humerus bone morphometry was unaffected by surgical repair timing

No description available.

Correct muscular activation of the body segments during an overhand throw is achieved when movement originates in the larger and more proximal legs and trunk and moves sequentially to the smaller, distal segments of the shoulder and arm. This sequence permits angular velocity to transfer progressively through the throw as part of an open kinetic chain. The athlete can summate angular velocity and segmental forces only if he is able to create a separation between the body segments during the movement pattern, and this separation is thus essential to effective segmental sequencing for activation of the trunk muscles to occur separately from distal segment motion. Limited mobility of the shoulder and scapula during the kinematic sequence will limit the ability of that segment to receive and contribute to the angular velocity of its proximal neighbors and to apply its own muscle torque to the throwing implement. This may result in compensatory motion of the proximal muscle groups to meet the demands placed on the body. To establish a link between compensatory activation of the trunk muscles and mobility in the rotator cuff and to apply this relationship to the pattern of the overhand throw, activity in the latissimus dorsi and external oblique/quadratus lumborum muscles was measured using surface electromyography in 40 college-age participants during arm flexion and lateral shoulder rotation. Muscle activation was recorded both before and after mobilization of relevant throwing muscles through targeted functional exercise. Results showed no significant change but suggested a general decrease in the level of peak muscle activation after participants engaged shoulder exercises. This is indicative of a downward trend in compensatory trunk activation during the initiation of shoulder motion. An increase in overall trunk muscle activity was also observed after exercise, which may imply a simultaneous engagement of the proximal throwing muscles in response to shoulder motion.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 4 uppsatser.

Universidade de São Paulo, Faculdade de Medicina; 2015. Introdução: Diante de uma rotura traumática do manguito rotador, não há evidência direta que comprove que os reparos realizados precocemente são mais eficazes que aqueles realizados tardiamente. Para abordar essa questão, ensaios biomecânicos e de morfometria óssea foram realizados após roturas extensas do manguito rotador realizadas precocemente (lesões agudas) e tardiamente (lesões crônicas), mediante a utilização de um modelo experimental em ratos. Método: 30 ratos adultos da raça Wistar foram aleatoriamente divididos em três grupos (I, II e III) e submetidos à secção completa dos tendões do supraespinal e infraespinal nos ombros esquerdos. Após oito semanas, nos animais dos grupos I e II, os tendões rotos pertencentes aos ombros esquerdos foram cirurgicamente reparados, e os tendões equivalentes nos ombros direitos foram seccionados e imediatamente reparados. Quatro semanas após os reparos (para os ratos do grupo II) ou oito semanas após os reparos (para os ratos do grupo I), os animais foram submetidos à eutanásia. Os ratos do grupo III foram submetidos à eutanásia oito semanas após a cirurgia de secção tendínea sem que houvesse ocorrido o reparo dos tendões rotos. Os ombros direitos dos animais do grupo III permaneceram intactos e serviram como controles. Após a eutanásia, todos os ratos tiveram seus ombros dissecados e os espécimes foram encaminhados para a realização de testes biomecânicos e de microtomografia computadorizada. Resultados: Para todos os parâmetros biomecânicos analisados, foram encontradas interações significantes referentes aos fatores tempo de cicatrização e reparo, considerando os reparos precoces e tardios. Com relação ao tendão supraespinal para o período de oito semanas de cicatrização, a força máxima até a falha foi significantemente maior nos reparos precoces em comparação aos reparos tardios (31,81 ± 3,86N vs 19,36 ± 6,14N; p < 0,001), bem como a rigidez (17,22 ± 4,35N/mm vs 10,85 ± 4,25N/mm; p=0,034), a tensão máxima até a falha (4,49 ± 2,02N/mm2 vs 1,97 ± 0,61N/mm2; p < 0,001) e o módulo de elasticidade (13,72 ± 5,29N/mm2 vs 6,47 ± 2,42 N/mm2; p=0,033). Com relação ao tendão infraespinal com oito semanas de cicatrização, a força máxima até a falha foi significantemente maior nos reparos precoces em comparação aos reparos tardios (21,26 ± 3,94N vs 12,74 ± 2,87N; p=0,005), assim como a rigidez (12,86 ± 2,65N/mm vs 7,21 ± 3,30N/mm; p=0,014). O grupo com reparo tardio com oito semanas de cicatrização obteve resultados nos testes biomecânicos semelhantes aqueles obtidos nos testes do grupo com lesão sem reparo com oito semanas de cicatrização. A avaliação microtomográfica não apresentou diferenças significantes na microarquitetura óssea entre os reparos realizados precocemente e tardiamente. Conclusões: Os resultados desse estudo demonstram que as roturas extensas do manguito rotador reparadas precocemente produzem um tecido cicatricial na junção ósteo-tendínea com melhores propriedades biomecânicas que as roturas reparadas tardiamente. Porém, ao analisar a morfometria óssea da porção proximal do úmero, verificou-se que os efeitos são equivalentes, tanto para os reparos realizados tardiamente quanto para os reparos realizados precocemente / Introduction: In the event of a traumatic rotator cuff tear, there is no direct evidence that supports early over late surgical repair. To address this knowledge gap, biomechanical and bone morphometry outcomes were assessed following early (acute) and late (chronic) massive rotator cuff tear repairs in an experimental rat model. Methods: 30 adult Wistar rats were randomly divided into three groups (I, II and III), then subjected to combined supraspinatus and infraspinatus tendon tears of the left shoulder. Eight weeks following the injury, animals from groups I and II had the tendons of the injured shoulder surgically repaired. In addition, these animals were subjected to the same injury on the contralateral shoulder, which was immediately repaired. The rats were euthanized four weeks (group II) or eight weeks (group I) following the repairs. Group III was euthanized eight weeks following the injury, without surgical repair of the left shoulder, and the intact right shoulders of this group were used as controls. Tissues from all groups were harvested and subjected to biomechanical testing and bone morphometry analysis. Results: In all biomechanical parameters analyzed, a significant interaction was observed between healing and repair timing. For the supraspinatus tendon with eight weeks healing time, biomechanical properties were significant increased in the early repair group compared to the late repair group, including maximum load to failure (31,81 ± 3,86N vs 19,36 ± 6,14N; p < 0,001), stiffness (17,22 ± 4,35N/mm vs 10,85 ± 4,25N/mm; p=0,034), maximum stress to failure (4,49 ± 2,02N/mm2 vs 1,97 ± 0,61N/mm2; p < 0,001) and modulus of elasticity (13,72 ± 5,29N/mm2 vs 6,47 ± 2,42 N/mm2; p=0,033). For the infraspinatus tendon with eight weeks healing time, biomechanical properties were also significantly increased in the early repair group, including maximum load to failure (21,26 ± 3,94N vs 12,74 ± 2,87N; p=0,005) and stiffness (12,86 ± 2,65N/mm vs 7,21 ± 3,30N/mm; p=0,014). There were no significant differences between the late repair with eight weeks of healing time and the group without surgical repair for supraspinatus and infraspinatus tendons. Concerning bone morphometry of the humeral head, no significant differences were observed when comparing early and late repair groups. Conclusions: The results from this study indicate that early surgical repair of a massive rotator cuff tear leads to increased biomechanical properties of the tissue after healing. However, proximal humerus bone morphometry was unaffected by surgical repair timing

RERUME: Les modèles personnalisés 3D sont de plus en plus demandés pour la planification chirurgicale et les recherches en biomécanique. L’objectif principal de cette thèse cotutelle était d’améliorer la méthode de reconstruction 3D à partir des images radiographies biplanes proposée par Lagacé, Ohl et al., afin que celle-ci puisse être plus facilement utilisée en clinique et qu’elle puisse permettre d’aider à la planification chirurgicale et/ou l’évaluation post-chirurgicale. Le système de radiographie biplane EOS à faible dose d’irradiation est le résultat d’une collaboration entre la société EOS imaging, l’institut biomécanique humaine Georges Charpak d’Arts et Métiers ParisTech, le laboratoire de recherche en imagerie et orthopédie (LIO) de l’école de technologie supérieure de Montréal, Georges Charpak, Jean Dubousset et Gabriel Kalifa (Dubousset et al. 2010). Le principe du détecteur de rayon X est basé sur les travaux développés par le Prof. Charpak, qui réduit significativement la dose de rayonnement comparé à la radiographie standard (Dubousset et al. 2010) Quatorze indices cliniques utilisés plus ou moins couramment en clinique pour le diagnostic et le suivi des pathologies de l’épaule et pour la planification chirurgicale et son évaluation post-opératoire ont été calculé. La justesse est acceptable (biais <1 mm sauf la distance sous acrominale) et une reproductibilité (2 fois écart-type inférieur à 5 mm ou 5° sauf 2 paramètres) qui est similaire à ce qui est présenté dans la littérature. L’approche proposée apporte sur une amélioration de la reconstruction dans un contexte où il serait intéressant qu’elle devienne utilisable en routine clinique. Bien que les améliorations soient encore nécessaires, cette contribution apporte une pierre à l’analyse de l’articulation intacte et pathologique et est prometteuse quant à la possibilité de son implantation dans la routine clinique pour évaluer les interventions chirurgicales en pré- et post-opératoire. / Three-dimensional subject-specific models are increasingly requested for surgical planning and research in biomechanics. The main objective of this cotutelle thesis was to improve the 3D reconstruction method using biplane radiography images proposed by Lagacé, Ohl et al., in order to facilitate its application in clinic, especially to assist surgical planning and/or post-surgical evaluation. The low-dose biplane radiography EOS was used and an improvement to the reconstruction method was proposed. Fourteen clinical indices used more or less routinely in clinical diagnosis for monitoring of shoulder disorders and for surgical planning and postoperative evaluation were calculated and evaluated. The accuracy is acceptable and reproducibility is similar to what is presented in the literature. The proposed approach brings an improvement of reconstruction in a context where it would be interesting for clinical routine use. Although improvements are required, this contribution brings a stone to the analysis of intact and pathological joint and is promising as to the possibility of its presence in the clinical routine for evaluating pre- and post-operative surgery.

No description available.