Introdução. Rupturas agudas do tendão de Aquiles afetam as propriedades mecânicas tendíneas. Estudos vêm preconizando o uso de mobilização precoce (tratamento acelerado) para evitar grandes prejuízos tendíneos. Entretanto, estudos que avaliem as propriedades mecânicas do tendão de Aquiles de humanos após ruptura total, submetidos à mobilização precoce, não foram encontrados na literatura específica da área. Objetivo: comparar as propriedades mecânicas e morfológicas do tendão de Aquiles entre pacientes submetidos a tratamento conservador e pacientes submetidos a tratamento acelerado (mobilização precoce) após a sutura do tendão de Aquiles. Materiais e Métodos: A amostra foi dividida intencionalmente em três grupos: controle (CTR; n=9), grupo conservador (CON; n=9; Pós-Cirúrgico: 28,3±3,6 meses) e grupo acelerado (ACE; n=9; Pós-Cirúrgico: 29,8±4,8 meses). Um dinamômetro isocinético foi utilizado para avaliação do torque dos grupos musculares flexores plantares e flexores dorsais do tornozelo. Foram obtidos os valores de área de secção transversa (AST) e comprimento do tendão (CT) de Aquiles. Para a avaliação da relação stress-strain os sujeitos realizaram duas contrações voluntárias máximas em rampa para flexão plantar no ângulo de 0º com duração de 10 segundos cada. Durante as duas contrações voluntárias máximas o deslocamento da JMT do músculo gastrocnêmio medial com o tendão de Aquiles foi verificado por meio de ultrassonografia utilizando uma sonda com arranjo linear. Simultaneamente a este procedimento, foi adquirido o sinal eletromiográfico do músculo tibial anterior, utilizado para a correção da força do tendão de Aquiles. As imagens necessárias para o cálculo do strain, bem como os sinais EMG e de torque foram sincronizados. Os valores máximos de stress, strain, força, deformação, módulo de Young, CT e AST foram comparados. Resultados: Não foram encontradas diferenças significativas nas propriedades mecânicas e morfológicas entre membros do grupo CTR. Não houve diferença significativa entre os membros saudáveis dos grupos CON e ACE e os do grupo CTR. Dessa forma, os membros saudáveis dos grupos CON e ACE foram utilizados como controle do membro lesão em ambos os grupos. Tanto no grupo CON, quanto no grupo ACE, o stress, a força e o módulo de Young apresentaram menores valores no membro lesionado, enquanto que o strain obtido em 10MPa e a AST foram maiores neste membro comparado ao contralateral saudável. Não houve diferença significativa no CT entre os membros, independente do grupo. Não foram encontradas diferenças significativas nas propriedades mecânicas, bem como na morfologia do tendão de Aquiles na comparação entre os membros lesionados dos grupos CON e ACE. Discussão: Esta maior complacência tendínea encontrada nos tendões lesados, independente do grupo, pode estar associada tanto as adaptações decorrentes da lesão que não recuperaram a níveis de normalidade, bem como a mudança nos hábitos de vida após a lesão. Além disso, o protocolo acelerado de reabilitação não foi capaz de reduzir as perdas advindas da ruptura tendínea. Tal resultado pode estar associado à especificidade do protocolo utilizado, que foi desenhado para ganho de flexibilidade no tornozelo e não para força muscular. Conclusão: Em um período mínimo de 21 meses de pós-operatório o tendão de Aquiles ainda apresenta efeitos deletérios da ruptura total nas propriedades estruturais e mecânicas do tendão. O protocolo de reabilitação utilizado não foi eficaz para a redução de tais efeitos. / Introduction. Acute Achilles tendon rupture affects the mechanical properties of the tendon. Despite the tendinous adaptations generated by decreased use, few studies have used early weight bearing (accelerated treatment) to avoid the large losses in the musculoskeletal tissues. In addition, studies that evaluated the mechanical properties of human Achilles tendon after acute rupture, subjected to early weight bearing were not found. Purpose: to compare the mechanical and morphological properties of the Achilles tendon between patients undergoing conservative and accelerated treatment, after Achilles tendon suture. Materials and Methods: subjects were intentionally allocated into three groups: control (CTR; n=9), conservative treatment (CON; n=9; Postsurgical time: 28.3±3.6 months) and accelerated treatment (ACC; n=9; Postsurgical time: 29.8±4.8 months). An isokinetic dynamometer was used to evaluate the torque production of ankle dorsi- and plantar-flexor muscles. The values of Achilles tendon cross sectional area (CSA) and length were obtained. To evaluate the stress-strain relation, patients were asked to produce two isometric maximal voluntary contractions during a ramp protocol (angle: neutral position; duration: 10 seconds) of the plantar flexor muscles. During the maximal contractions the displacement of the myotendinous junction of the gastrocnemius medialis muscle was evaluated by ultrasound with a linear array probe. Simultaneously, the electromyography (EMG) signal of the tibialis anterior was recorded, and used to correct the Achilles tendon force. The ultrasound images, EMG signals and torque were synchronized. The maximal values of stress, strain, force, displacement, Young’s modulus, tendon length and CSA were compared. Results: there were no significant differences in the morphological and mechanical properties between limbs in the CTR group. Moreover, there were no significant differences in the morphological and mechanical properties between healthy limbs amongst groups. Thus, the healthy limbs of the CON and ACC groups were used as control of the injured limb. In CON and ACC groups the stress, force and Young’s modulus had lower values in the injured limb compared to the contralateral healthy limb, while the strain obtained at 10MPa and the CSA were higher in the injured limb. There were no significant differences in the tendon length between groups and limbs. Moreover, there were no significant differences in the morphological and mechanical properties between injured limbs (CON and ACC). Discussion: The highest tendinous compliance found on the injured tendons, independent of the group might be associated to both the adaptations due to injury that did not return to normal healthy levels and to possible changes in the daily life activities after injury. In addition, the accelerated treatment was unable to reduce the losses due to tendon rupture. These results might be associated to the specificity of the rehabilitation protocol used that was designed for the gain of flexibility and not for strength gains. Conclusion: Twenty-one months post-surgery were unable to recover the deleterious effects of acute Achilles tendon rupture on the structural and mechanical tendon properties. The accelerated rehabilitation protocol was ineffective to reduce these deleterious effects.

Introdução. Rupturas agudas do tendão de Aquiles afetam as propriedades mecânicas tendíneas. Estudos vêm preconizando o uso de mobilização precoce (tratamento acelerado) para evitar grandes prejuízos tendíneos. Entretanto, estudos que avaliem as propriedades mecânicas do tendão de Aquiles de humanos após ruptura total, submetidos à mobilização precoce, não foram encontrados na literatura específica da área. Objetivo: comparar as propriedades mecânicas e morfológicas do tendão de Aquiles entre pacientes submetidos a tratamento conservador e pacientes submetidos a tratamento acelerado (mobilização precoce) após a sutura do tendão de Aquiles. Materiais e Métodos: A amostra foi dividida intencionalmente em três grupos: controle (CTR; n=9), grupo conservador (CON; n=9; Pós-Cirúrgico: 28,3±3,6 meses) e grupo acelerado (ACE; n=9; Pós-Cirúrgico: 29,8±4,8 meses). Um dinamômetro isocinético foi utilizado para avaliação do torque dos grupos musculares flexores plantares e flexores dorsais do tornozelo. Foram obtidos os valores de área de secção transversa (AST) e comprimento do tendão (CT) de Aquiles. Para a avaliação da relação stress-strain os sujeitos realizaram duas contrações voluntárias máximas em rampa para flexão plantar no ângulo de 0º com duração de 10 segundos cada. Durante as duas contrações voluntárias máximas o deslocamento da JMT do músculo gastrocnêmio medial com o tendão de Aquiles foi verificado por meio de ultrassonografia utilizando uma sonda com arranjo linear. Simultaneamente a este procedimento, foi adquirido o sinal eletromiográfico do músculo tibial anterior, utilizado para a correção da força do tendão de Aquiles. As imagens necessárias para o cálculo do strain, bem como os sinais EMG e de torque foram sincronizados. Os valores máximos de stress, strain, força, deformação, módulo de Young, CT e AST foram comparados. Resultados: Não foram encontradas diferenças significativas nas propriedades mecânicas e morfológicas entre membros do grupo CTR. Não houve diferença significativa entre os membros saudáveis dos grupos CON e ACE e os do grupo CTR. Dessa forma, os membros saudáveis dos grupos CON e ACE foram utilizados como controle do membro lesão em ambos os grupos. Tanto no grupo CON, quanto no grupo ACE, o stress, a força e o módulo de Young apresentaram menores valores no membro lesionado, enquanto que o strain obtido em 10MPa e a AST foram maiores neste membro comparado ao contralateral saudável. Não houve diferença significativa no CT entre os membros, independente do grupo. Não foram encontradas diferenças significativas nas propriedades mecânicas, bem como na morfologia do tendão de Aquiles na comparação entre os membros lesionados dos grupos CON e ACE. Discussão: Esta maior complacência tendínea encontrada nos tendões lesados, independente do grupo, pode estar associada tanto as adaptações decorrentes da lesão que não recuperaram a níveis de normalidade, bem como a mudança nos hábitos de vida após a lesão. Além disso, o protocolo acelerado de reabilitação não foi capaz de reduzir as perdas advindas da ruptura tendínea. Tal resultado pode estar associado à especificidade do protocolo utilizado, que foi desenhado para ganho de flexibilidade no tornozelo e não para força muscular. Conclusão: Em um período mínimo de 21 meses de pós-operatório o tendão de Aquiles ainda apresenta efeitos deletérios da ruptura total nas propriedades estruturais e mecânicas do tendão. O protocolo de reabilitação utilizado não foi eficaz para a redução de tais efeitos. / Introduction. Acute Achilles tendon rupture affects the mechanical properties of the tendon. Despite the tendinous adaptations generated by decreased use, few studies have used early weight bearing (accelerated treatment) to avoid the large losses in the musculoskeletal tissues. In addition, studies that evaluated the mechanical properties of human Achilles tendon after acute rupture, subjected to early weight bearing were not found. Purpose: to compare the mechanical and morphological properties of the Achilles tendon between patients undergoing conservative and accelerated treatment, after Achilles tendon suture. Materials and Methods: subjects were intentionally allocated into three groups: control (CTR; n=9), conservative treatment (CON; n=9; Postsurgical time: 28.3±3.6 months) and accelerated treatment (ACC; n=9; Postsurgical time: 29.8±4.8 months). An isokinetic dynamometer was used to evaluate the torque production of ankle dorsi- and plantar-flexor muscles. The values of Achilles tendon cross sectional area (CSA) and length were obtained. To evaluate the stress-strain relation, patients were asked to produce two isometric maximal voluntary contractions during a ramp protocol (angle: neutral position; duration: 10 seconds) of the plantar flexor muscles. During the maximal contractions the displacement of the myotendinous junction of the gastrocnemius medialis muscle was evaluated by ultrasound with a linear array probe. Simultaneously, the electromyography (EMG) signal of the tibialis anterior was recorded, and used to correct the Achilles tendon force. The ultrasound images, EMG signals and torque were synchronized. The maximal values of stress, strain, force, displacement, Young’s modulus, tendon length and CSA were compared. Results: there were no significant differences in the morphological and mechanical properties between limbs in the CTR group. Moreover, there were no significant differences in the morphological and mechanical properties between healthy limbs amongst groups. Thus, the healthy limbs of the CON and ACC groups were used as control of the injured limb. In CON and ACC groups the stress, force and Young’s modulus had lower values in the injured limb compared to the contralateral healthy limb, while the strain obtained at 10MPa and the CSA were higher in the injured limb. There were no significant differences in the tendon length between groups and limbs. Moreover, there were no significant differences in the morphological and mechanical properties between injured limbs (CON and ACC). Discussion: The highest tendinous compliance found on the injured tendons, independent of the group might be associated to both the adaptations due to injury that did not return to normal healthy levels and to possible changes in the daily life activities after injury. In addition, the accelerated treatment was unable to reduce the losses due to tendon rupture. These results might be associated to the specificity of the rehabilitation protocol used that was designed for the gain of flexibility and not for strength gains. Conclusion: Twenty-one months post-surgery were unable to recover the deleterious effects of acute Achilles tendon rupture on the structural and mechanical tendon properties. The accelerated rehabilitation protocol was ineffective to reduce these deleterious effects.

Orientador: Edson Rosa Pimentel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T20:28:03Z (GMT). No. of bitstreams: 1 Oliveira_LeticiaPradode_M.pdf: 4812379 bytes, checksum: ed278304758adcd22ac4272f33a145ac (MD5) Previous issue date: 2013 / Resumo: As estatinas, inibidores da 3-hidroxi-3-metilglutaril-coenzima A redutase, são fármacos utilizados para o tratamento de hipercolesterolemia - níveis elevados de colesterol no sangue. Embora sejam considerados medicamentos seguros e eficazes, possuem inúmeros efeitos adversos como, por exemplo, miopatias e hepatopatias. Além disso, há relatos de lesões em tendões associadas ao uso destes medicamentos e os mecanismos responsáveis por este efeito adverso não estão bem esclarecidos. Portanto, este estudo teve como objetivo avaliar as possíveis alterações morfológicas, bioquímicas e funcionais no tendão calcanear de ratos após tratamento crônico com estatinas. Os ratos foram divididos nos seguintes grupos: tratados com a atorvastatina (A-20 e A-80), sinvastatina (S-20 e S-80), carboximetilcelulose utilizado como o veículo (V) e um grupo que não recebeu tratamento (ST). As doses de atorvastatina e sinvastatina foram calculadas utilizando extrapolação alométrica com base nas doses de 20mg/dia e 80 mg/dia, recomendadas para os seres humanos. Os ratos foram sacrificados após dois meses de tratamento e os tendões foram coletados para análises morfológicas, bioquímicas e funcionais. Para as análises morfológicas em microscopia de luz os cortes de tendões foram corados com Hematoxilina-eosina e Azul de Toluidina. Foram realizadas medidas de birrefringência através da microscopia de polarização. Para análises bioquímicas, os tendões foram processados e analisados de acordo com as seguintes técnicas: eletroforese em gel de agarose para análise de glicosaminoglicanos sulfatados; zimografia para detecção de metaloproteinases (MMPs) dos tipos -2 e -9; Western Blotting para colágeno I, dosagem de proteínas não-colagênicas, glicosaminoglicanos e hidroxiprolina. Os tendões também foram submetidos a testes biomecânicos. Todos os resultados foram analisados utilizando ANOVA-one-way, seguida pelo teste de Tukey, com exceção dos dados de birrefringência, que foram analizados pelo teste de Mann-Whitney. A concentração de proteínas não-colagênicas em todos os grupos tratados com estatinas foi menor em relação ao grupo V. Houve um aumento significativo de pro-MMP-2 no grupo A-80 e MMP-2 ativa em S-20 comparado ao grupo ST. Foi observado também um aumento significativo de pro-MMP-9 nos grupos A-80 e S-20 e um aumento de MMP-9 ativa no grupo A-20 em relação ao grupo ST. O grupo A-20 apresentou menor quantidade de colágeno I quando comparado ao grupo ST e no grupo S-20 foi observada uma maior concentração de hidroxiprolina em relação aos grupos ST e V. A dosagem de glicosaminoglicanos mostrou um aumento significativo no grupo A-20 e o grupo S-80 apresentou menor concentração deste componente em relação ao grupo ST e V respectivamente. As medidas de birrefringência dos grupos A-20, A-80 e S-80 revelaram um menor grau de organização das fibras de colágeno nestes grupos em relação ao grupo V. Durante os ensaios biomecânicos os tendões dos grupos A-20, A-80 e S-20 foram menos resistentes à ruptura quando comparados com o grupo ST. Nossos resultados sugerem claramente que o tratamento com estatinas provoca notáveis alterações no tendão calcanear de ratos. Além de promover o desequilíbrio entre a síntese e degradação de componentes da matriz extracelular e a desorganização das fibras de colágeno, as estatinas também trouxeram prejuízos às propriedades biomecânicas dos tendões, fatores que associados, podem tornar os tendões mais predispostos a rupturas e possivelmente induzir micro lesões / Abstract: Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. These drugs are used to treat hypercholesterolemia - high cholesterol levels in the blood. Although considered safe and effective drugs, they have numerous adverse effects such as myopathy and liver toxicity. In addition, there are reports of tendon lesions associated with statins and the mechanisms responsible for this adverse effect are not clear. Therefore, this study aimed to evaluate possible morphological, biochemical and functional alterations in Achilles tendon of rats after chronic treatment with statins. The rats were divided into the following groups: treated with simvastatin (S-20 and S-80), atorvastatin (A-20 and A-80), carboxymethylcellulose used as the vehicle (V) and a group that received no treatment (NT). Doses of statins were calculated using allometric scaling with reference to 80mg/day and 20mg/day doses recommended for humans. The rats were euthanized after two months of treatment and the tendons were collected for morphological, biochemical and functional analysis. For morphological analysis by light microscopy, sections of tendons were stained with hematoxylin-eosin and toluidine blue. Birefringence measurements were performed by polarizing microscopy. For biochemical analysis, the tendons were processed and analyzed according to the following techniques: Agarose gel electrophoresis for the analysis of sulphated glycosaminoglycans; zymography for detecting metalloproteinases (MMPs) -2 and -9; Western Blotting for collagen I, dosage of non-collagenous proteins, glycosaminoglycans and hydroxyproline. The tendons were also submitted to biomechanical tests. All of the results were analyzed by ANOVA-one-way followed by Tukey test, except the birefringence data that were analyzed by Mann-Whitney test. The concentration of non-collagenous proteins in all groups treated with statins was lower than in V group. There was a significant increase in pro-MMP-2 in A-80 group and active MMP-2 in S-20 compared to the ST group. We observed a significant increase in pro-MMP-9 in A-80 and S-20 groups. The A-20 group showed a significant increase in the levels of active MMP-9 in relation to the ST group. The A-20 group showed less collagen I when compared to the ST group and in the S-20 group was observed a higher concentration of hydroxyproline in relation to the both ST and V groups. The dosage of glycosaminoglycans showed a significant increase in A-20 group and S-80 group showed lower concentration of this component in relation to the ST and V groups respectively. The birefringence measurements of the A-20, A-80 and S-80 groups showed a lower degree of organization of the collagen fibers in these groups than in the V group. During the biomechanical tests the tendons of the A-20, A-80 and S-20 groups were less resistant to rupture when compared to the ST group. Our results clearly suggest that treatment with statins causes remarkable changes in the Achilles tendon. Besides promoting the imbalance between the synthesis and degradation of extracellular matrix components and disorganization of collagen fibers, statins also brought losses to the biomechanical properties of tendons. These factors associated can make the tendons more prone to ruptures and possibly induce micro injuries / Mestrado / Histologia / Mestra em Biologia Celular e Estrutural

The Achilles tendon is the largest tendon in the human body, which elastically stores and releases energy to facilitate walking and running. Tendons can suffer from a range of pathologies, most notably that of complete rupture, which affects athletes, physically active workers and the aged. There is a growing demand for in vivo methods of objectively measuring tendon health for aiding diagnosis, monitoring therapy and for assessment of new treatments. Knowledge of the changes in mechanical properties during the healing process is also limited and new methods to accurately and consistently estimate these could provide insights into the healing process and guide future research efforts. This thesis presents the development and use of 2D ultrasound elastography, a quantitative strain estimation imaging technique, as a tool to measure changes in the tensile mechanical properties of the Achilles tendon. This technique performs frame-to-frame block matching of image texture to track motion in an ultrasound signal sequence and create a strain estimation field from the spatial derivative of the motion. Elastography in the image-lateral direction of sagittal plane scans is of particular interest as this is in line with the longitudinal axis of the tendon, but presents extra accuracy issues from out of plane motion and lower image spatial resolution. Tendon rupture also presents unique problems to image acquisition and analysis- patient pain and safety are important considerations and disruption of the ultrasound texture can make 2D motion tracking more difficult. A new 2D elastography block matching algorithm, named `AutoQual', was developed to enable accurate tracking of motion in the image-lateral direction and reduce the impact of artefacts and errors common with damaged Achilles tendons image sequences. It was shown to outperform a multiscale block matching method when tested using ultrasound sequences from in vivo and gelatine phantom experiments. The input parameters of this algorithm were then optimised using the phantom data for benchmarking. The AutoQual algorithm was then used to analyse ultrasound sequences from a 24-week longitudinal study of 21 subjects with ruptured Achilles tendons to assess lateral, axial and principal strains during controlled passive motion of the foot or axial palpation of the ultrasound probe. Lateral and principal strains from controlled dorsiflexion were shown to be more repeatable and more sensitive to change than axial strains with manual palpation. This experience with lateral strain imaging from ruptured Achilles tendons gave an increased knowledge of the strain imaging artefacts and features that can occur. These are described in detail in order that they may be further mitigated in quantitative analysis by optimising acquisition protocols, further amendment of the block tracking algorithm, or exclusion of erroneous areas when selecting regions of interest. Regularisation is a potential solution to some common artefacts such as discontinuities from poor tracking in shadow regions. Regularisation of the lateral displacement fields is investigated using 2D bicubic smoothing splines. The regularisation parameters used are shown to have minimal effect on quantitative analysis and can aid visual clarity or reduce artefacts within certain settings. However, regularisation was also shown to cause large errors when parameters were set more aggressively. Finally, it is identified that cumulative lateral strain measurement of the Achilles and other tendons is feasible but that future work is needed to further improve the quality of force and cross sectional area measurements in order to infer mechanical properties accurately. Repeatable high force motion protocols also need to be developed to measure healthy tendons and to ensure comparable results between different patients and research groups.

M.Tech.

Treatment of acute Achilles tendon ruptures has long been controversial. Several treatment options exist for patient with variable harms and benefits to each. Recognizing that decision of treatment option is preference-sensitive, this thesis focused on updating the current literature on Achilles tendon rupture management to facilitate the creation of a patient decision aid. A network meta-analysis of all treatment options for acute Achilles tendon ruptures was performed. Results demonstrated that minimally invasive surgery options were associated with lower complications and lower complications requiring surgery. Return to sport was similar amongst all treatment groups. With guidance from the Ottawa Decision Support Framework and the International Patient Decision Aid Standards, a three-tiered protocol for development, alpha testing and field-testing a novel patient decision aid is outlined next. The patient decision aid will be reviewed and revised iteratively by multi-disciplinary steering group. This protocol will act as a framework for further orthopaedic patient decision aid development.

Background: Achilles tendinopathy is a common debilitating running related injury. Achilles tendon loading force has been hypothesized as a contributor to Achilles tendinopathy. Loading force through the Achilles tendon during running is impacted by many factors such as footwear and foot strike pattern. Achilles tendon biomechanical (Achilles tendon cross-sectional area, thickness, echogenicity, stiffness, and T2*) responses to loading forces are variable and measurable in vivo. These responses impact the physiologic function of the tendon. Aims: 1) To evaluate baseline Achilles tendon biomechanical characteristics associated with a runner's habitual foot strike pattern. 2) To evaluate single running bout Achilles tendon biomechanical changes to varied forces in runners while maintaining their habitual foot strike pattern. This will be accomplished using minimalist and cushioned running shoes. Methods: 29 recreational runners were recruited. Runners completed two separate 5.3 km running sessions wearing alternating shoe types (cushioned and minimalist) at a pace of 3.15 m/s. Prior to running each day, participants had 32 retroreflective markers placed upon them for motion analysis collection. Additionally, participants had their Achilles tendon imaged via ultrasound pre and post run. On a separate day 24 of the participants underwent an ultrashort echo time (UTE) MRI imaging session of their Achilles tendon. Results: Achilles tendon stiffness was 20% greater in non-rear foot strike runners when compared with rear foot strike runners (p = 0.0166). Achilles tendon CSA, thickness, echogenicity, and T2* were not different between running groups (p > 0.05). Both foot strike pattern groups experienced significant Achilles tendon CSA and thickness decreases from pre to post run in minimalist and cushioned shoes (p < 0.05). Both running groups in cushioned shoes and the non-heel strike runners in minimalist shoes experienced significant increases in Achilles tendon echogenicity from pre to post run. Only non-rear foot strike runners had a significant increase in Achilles tendon stiffness while running in cushioned shoes (p = 0.03). Conclusions: The Achilles tendons of non-rear foot strike runners were significantly stiffer than those of rear foot strike runners. This Achilles tendon characteristic may be attributable to differences in Achilles tendon loading force while running but needs further research. Both groups of runners experienced multiple single running bout Achilles tendon changes as measured via ultrasound. Although loading forces varied within groups in different shoes and between foot strike pattern groups, all Achilles tendon changes were similar regardless of loading forces from pre to post run.

Background: Achilles tendinopathy is a common and debilitating condition among female ballet dancers due to the large repetitive loading forces placed on their Achilles tendons during rehearsals and performances. Tendon health problems in females are exacerbated by a lack of understanding about how energy availability influences tendons. Ballet dancers, as aesthetic athletes, are vulnerable to low energy availability and can enter a spectrum disorder, relative energy deficiency in sport, that consists of low energy availability (with or without disordered eating), menstrual cycle dysfunction, and low bone mineral density (BMD). Aims: 1) To investigate the relationship between insufficient caloric intake and Achilles tendon health in pre-professional ballet dancers. 2) To evaluate if symptoms of relative energy deficiency in sport such as low BMD and menstrual irregularity can be matched with Achilles tendon structural damage in pre-professional ballet dancers. 3) To analyze if there is a relationship between BMD and nutrition in pre-professional ballet dancers. Methods: 30 pre-professional ballet dancers were recruited. Over the course of a 16-week training and performance period, the dancers underwent four ultrasound imaging sessions and two MRI sessions investigating their Achilles tendons. They also underwent one full body DXA scan and completed four ASA24 dietary recall surveys. The dancers additionally filled out questionnaires describing their menstrual history and current Achilles tendon health. At the end of the study, dancers were organized into calorie sufficiency groups (sufficient or insufficient). Results: Within both calorie groups, the Achilles tendon was significantly thicker at the end of the study as compared to the start of the study (p=.046). Within both calorie groups, echogenicity was significantly higher at the first two ultrasound imaging sessions than it was at the last two (p<.05). Additionally, the calorie sufficient group's tendons had a significantly higher echogenicity than the calorie insufficient group at the first two ultrasound imaging sessions (p<.05). There were significantly more dancers in the calorie insufficient group that experienced changes to their menstrual cycle (p=.007). Conclusion: Participants in the calorie sufficient group had significantly more hyperechoic tendons than those in the calorie insufficient group at the start of the study, and all participants saw a significant drop in tendon echogenicity halfway through the study. The results of this study suggest that a better understanding of how average caloric intake affects tendon health in dancers is necessary in order to help treat and prevent AT injuries in this dance population.

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)

O desenvolvimento de novos recursos terapêuticos capazes de acelerar o processo de reparo tem proporcionado avanços significativos no tratamento de lesões tendinosas. O objetivo do presente estudo foi analisar a influência da radiação LASER HeNe em cicatrização de tendões. Foi desenvolvido um modelo experimental de lesão de tendão de Aquiles através de um procedimento minimamente invasivo em coelhos adultos. Foram utilizados 40 animais distribuídos em quatro grupos de 10 animais (I, II III IV). No grupo I a lesão do tendão foi unilateral (pata direita) e o tendão lesado não recebeu estímulos com LASER. No grupo II a lesão foi unilateral (pata direita) e o tendão lesado recebeu estímulos com LASER. No grupo III a lesão do tendão foi bilateral e apenas a pata direita foi estimulada com LASER. No grupo IV foi realizada \"Sham Operation\" bilateralmente e apenas o tendão da pata direita recebeu estímulo com LASER. Todos os animais foram tratados com dose a 5 J/cm2 de forma pontual com contato direto durante 8 dias consecutivos, diariamente. Após este período os animais foram sacrificados e os tendões de Aquiles submetidos a ensaios mecânicos de tração em máquina de ensaio mecânico. Foram ensaiados 71 tendões, sendo 09 descartados. Embora não tenhamos observado diferença estatística significante nas comparações feitas entre os grupos, podemos notar que existiu uma tendência apontando que os tendões estimulados com LASER apresentaram resistência menor que os grupos controles. Estes resultados sugerem que o LASER diminuiu a resistência dentro das condições estudadas. Relevância Clínica: O presente trabalho mostra o conceito de que a irradiação LASER pode diminuir a resistência mecânica da cicatrização tendinosa em fases precoces do processo. / The development of new therapeutic resources addressing accelerating the repairing process has proportioned a meaningful advance in the treatment of tendon lesions. The purpose of the present study was to analyse the influence of He-Ne LASER radiation on tendon healing. An experimental model of Achilles tendon lesion was developed through a minimally invasive procedure in adults rabbits. We used 40 animals divided in groups of 10 animals each. In group I the tendon lesion was unilateral (right-paw) and the injured tendon did not receive LASER stimulation. In group II the lesion was unilateral (right-paw) and only, the injured side received LASER stimulation. In group III the tendon lesion was bilateral and only the right-paw was stimulated by LASER. In group IV bilateral sham operation was performed and only the right - paw received LASER stimulation. All the animals were treated with 5 J/cm2 dosis in a punctual way with direct contact for 8 successive days. After this period the animals were killed and the Achilles tendons were submitted to mechanical tests in traction on a mechanical testing machine. Seventy-one tendons were tested and 9 were discarded. No statiscally significant difference was observed in the comparison done between groups, however we could notice a tendency suggesting that the tendons stimulated by LASER presented a lesser mechanical resistance. These results suggest that LASER probably reduces the resistance in the studied conditions. Clinic Relevance: The present study supports the concept that LASER irradiation may induce an attenuation of the mechanical properties of the healing tendon in a very early phasis of the proccess.