A maioria dos casos de pé torto congênito tratados pelo método de Ponseti requer a secção do tendão calcâneo para correção do equino residual. Evidências clínicas sugerem que há completa cicatrização entre os cotos tendíneos, mas este processo reparativo ainda não foi suficientemente estudado. Esta investigação teve como objetivo avaliar o processo de reparação que ocorre após a secção percutânea do tendão calcâneo para a correção do equino residual no pé torto congênito idiopático tratado pelo método de Ponseti. Por meio de estudo prospectivo, foram analisadas 37 tenotomias em 26 pacientes com pé torto congênito idiopático tratados pelo método de Ponseti, com seguimento mínimo de um ano após a secção. A tenotomia foi realizada percutaneamente com agulha biselada de grosso calibre, sob sedação e anestesia local. O exame ultrassonográfico foi feito logo após a secção tendínea para assegurar que ela tenha sido completa e mensurar o afastamento entre os cotos. A reparação foi estudada por meio da ultrassonografia realizada três semanas, seis meses e um ano após a tenotomia. A ultrassonografia, realizada imediatamente após o procedimento, mostrou que, em alguns casos, feixes tendíneos residuais persistiam entre os cotos, mas foram completamente seccionados, em seguida, sob controle ultrassonográfico. Houve afastamento médio de 5,65 mm ± 2,26 (2,3 a 11,0 mm) entre os cotos tendíneos logo após a secção. Em um caso ocorreu sangramento maior que o habitual, que foi controlado com pressão local e não provocou interferência no tratamento. Após três semanas, a ultrassonografia mostrou regeneração tendínea com preenchimento do espaçamento entre os cotos por tecido hipoecoico com ecotextura irregular e com restituição da continuidade entre os cotos demonstrada dinamicamente pela transmissão de movimentos do músculo tríceps sural para o calcanhar. Seis meses após a tenotomia, o exame ultrassonográfico evidenciou que o tecido de reparação apresentava ecotextura de aspecto fibrilar e, quando comparado ao tendão normal, havia leve ou moderada hipoecogenicidade e espessamento cicatricial. Um ano após a tenotomia, o exame ultrassonográfico mostrou estrutura fibrilar na região de reparação, com ecogenicidade semelhante ao tendão normal, mas ainda apresentando espessamento tendíneo cicatricial. Em termos gerais, ocorreu rápida cicatrização após a secção percutânea do tendão calcâneo, que restabeleceu a continuidade entre os cotos. Ao final do período de observação, o tecido de reparação tendínea apresentou aspecto ultrassonográfico semelhante ao lado normal, exceto por leve espessamento, o que sugere um mecanismo de reparação predominantemente intrínseco. / Most cases of congenital clubfoot treated by the Ponseti technique require percutaneous Achilles tenotomy in order to correct the residual equinus. Clinical evidences suggest that complete healing occurs between the cut tendon stumps, but there have not yet been any detailed studies investigating this reparative process. This study was performed to assess the Achilles tendon repair after percutaneous sectioning to correct the residual equinus of clubfoot treated by the Ponseti method. A prospective study analyzed 37 tenotomies in 26 patients with clubfoot treated by the Ponseti technique, with a minimum follow-up of one year after the section. The tenotomy was performed percutaneously with a large-bore needle bevel with patient sedation and local anesthesia. Ultrasonographic scanning was performed after section to ascertain that the tenotomy had been completed and to measure the stump separation. In the follow-up period, the reparative process was followed ultrasonographically at three weeks, six months and one year post-tenotomy. The ultrasonography performed immediately after the procedure showed that in some cases, residual strands between the tendon ends persisted, and these were completely sectioned under ultrasound control. A mean retraction of 5.65 mm ± 2.26 (range, 2.3 to 11.0 mm) between tendon stumps after section was observed. Unusual bleeding occurred in one case and was controlled by digital pressure, with no interference with the final treatment. After three weeks, ultrasonography showed tendon repair with the tendon gap filled with irregular hypoechoic tissue, and also with transmission of muscle motion to the heel. Six months after tenotomy, there was structural filling with a fibrillar aspect, mild or moderate hypoechogenicity, and tendon scar thickening when compared to a normal tendon. One year after tenotomy, ultrasound showed a fibrillar structure and the echogenicity at the repair site that was similar to a normal tendon, but with persistent mild tendon scarring thickness. It was observed that there was a fast reparative process after Achilles tendon percutaneous sectioning that reestablished continuity between stumps. The reparative tissue evolved to tendon tissue with a normal ultrasonographic appearance except for mild thickening, suggesting a predominantly intrinsic repair mechanism

Abstract Type I collagen is the main connective tissue protein in vertebrates. The cross-linking and correct organisation of the molecules is crucial for the proper function of the tissue. Traditionally collagen cross-linking has been studied using chemical cross-link analyses. However, this does not distinguish between the collagen types or the location of the cross-link within the molecule. The focus in this work was to study the carboxyterminal telopeptide domain of type I collagen for the differently cross-linked forms. An immunochemical approach was used and a new immunoassay, SP4, was developed for the detection of immaturely cross-linked peptide forms. The differently cross-linked structures were purified and characterised from human bone by using SP4 together with the earlier developed ICTP assay for trivalently cross-linked C-terminal telopeptide form. It was found that the majority of the trivalent cross-links in the C-terminal telopeptide were presently unknown structures, other than pyridinoline. A non-cross-linked form of C-terminal telopeptide of α1-chain of type I collagen was also discovered in bone. The epitope of the ICTP assay was characterised and found to reside in the phenylalanine rich region of the ICTP peptide. MMP-9, but not cathepsin K, mediated breakdown of the collagenous matrix was found to produce a peptide detectable by the ICTP assay. Healthy human Achilles tendon comprises mainly of type I collagen. In ruptured Achilles tendons, an increased type III collagen content was found. Since the synthesis of type III collagen was not increased, it is postulated that the type III collagen must have accumulated over a long period of time indicative of a long-lasting microtraumatic process in the tendon before the total rupture occurred. The ICTP content was increased and the ratio of SP4 to ICTP decreased in calcified stenotic aortic valves suggesting a change in the molecular organisation and cross-linking towards the type found in human bone. The total collagen content was dramatically decreased in the calcified valves. Both in the Achilles tendons and in the aortic valves, the ICTP content was found to decrease with age with a concomitant increase in the variants of the C-terminal telopeptide structures detectable with the SP4 assay, pointing to a change in the molecular organisation of the collagenous matrix in these tissues.

Abstract The Achilles tendon is the largest tendon in the human body and is affected by many diseases and is vulnerable to many forms of damage due to the heavy loads it must bear. Rupture of the Achilles tendon has become more common in recent times, with an almost four-fold increase in prevalence from 1979–1990 to 1991–2000 and a peak incidence of 19 ruptures per 100 000 of population in 1999 in our epidemiological assessment. The incidences of major complications, re-rupture and deep infection, increased along with primary ruptures, peaking in 1999. The results after successful primary repair are good in over 90% of cases, as we have shown in a randomized study and in a review of the literature, and the result after re-rupture is still good in about 70% of cases, but achieving good performance after deep infection is a highly random matter. Our retrospective survey did not identify any good results, but the deep infection cases in our randomized study showed good performance due to prompt action taken for their treatment. The best method for treating a ruptured Achilles tendon has been under debate for almost 100 years, with surgery and conservative methods advocated to equal extents. We have advocated surgical treatment as the primary choice and conservative treatment is given for selected high risk patients, for example patients with diabetes, skin problems, systemic use of corticosteroids or severe other illness. The type of surgery technique is not a straightforward choice, either, and various forms of open surgery and percutaneous techniques exist. We compared an end-to-end simple suture with the same suture augmented with one central gastrocnemius turn-over flap in a randomized series of 60 patients and found no differences with respect to subjective complaints, calf muscle strength or tendon elongation with time. The end-to-end technique is simpler and is therefore justified as the primary method of choice for the surgical repair of fresh complete Achilles tendon ruptures. The tissue composition has been shown to alter not only with time but also after repeated tearing of the tendon collagen fibres. A normal tendon is mainly composed of type I collagen, but the rupture areas express more type III collagen, which is thinner and withstands loads less effectively. Type III collagen accumulates slowly in the tendon, since its production does not increase very much, a situation that is indicative of microtrauma. Crosslinking of the fibres is important for collagen matrix properties, and we found that there is a change in the quality of crosslinking with age and that this may have role in the observed changes in tendon stiffness, as also noted in other studies. We also studied the appearance of tenascin-C at the rupture site in the Achilles tendon and at two other sites in the same tendon, but found no difference in its expression. It has been proposed that tenascin-C may take part in the tendon’s reaction to loading, but its exact function remains unknown.

The main goal of the project was to compare how the Achilles tendon is affected while running with traditional shoes, minimalistic shoes and barefoot. Displacement and strain were calculated both for different shoes and for different foot strike patterns. The calculations were done with a speckle tracking algorithm and displacement was calculated for three different depths in the tendon: deep layer, mid layer and superficial layer. The goal was also to conduct this analysis after a review of the algorithm used. The review of the algorithm focused on the size of the region of interest, kernel size and frequency. Literature study showed that it is more common to use a smaller kernel size, but the same shape. The region of interest was chosen depending on the size of the tendon. Displacement and strain in the Achilles tendon was calculated for seven subjects and the result did not show any difference in amount of mean deformation due to different shoe types or foot strike patterns. It was a small sample group but the result indicated a difference in peak displacement between deep and superficial layer depending on different shoe types and foot strike patterns. The difference in peak displacement between deep and superficial layer was lowest when running barefoot, larger when running with minimalistic shoes and greatest when running with traditional shoes. This result was only achieved when running with rear foot strike pattern. When running with fore foot strike pattern the difference in peak displacement between layers did not change with different conditions. In all conditions the difference in peak displacement between the layers was greater when running with rear foot strike pattern than when running with front foot strike pattern. The deep layer displaced more than the superficial layer (p<0.01) for all conditions and foot strike patterns.

Much is known about running economy while running on level ground surfaces. However, with the dynamic of elevation changes during running, more research is needed to understand how various grades that will favor respective mechanics. PURPOSE: In this study, we focused on determining whether certain running mechanics and anatomy would predict a runner's oxygen uptake between downhill versus uphill running. METHODS: Twenty-one experienced runners completed six 5-min running trials (1 shoe x 3 grades x 2 visits) in a Saucony marathon racing shoe model (Type A) on level (3.83 m/s), uphill (+4% grade at 3.35 m/s), and downhill ( ˆ’4% grade at 4.46 m/s) conditions. These treadmill speeds at each grade were predicted as metabolic equivalents through all grades. We measured submaximal oxygen uptake and carbon dioxide production during the entire trial duration with the last 3 min of each trial being averaged. A best-fitting line was generated through oxygen uptake versus grade to classify whether runners were more economical in uphill or downhill conditions relative to other subjects. The slope of this line indicated whether runners were more economical at uphill or downhill running, where a positive slope represented a more economical uphill versus downhill runner. Various running mechanics were measured using Vicon Nexus and a Bertec treadmill. A linear regression determined any correlations between peak vertical force, stride rate, plantar velocity, and ground time against uphill/downhill running ability. RESULTS: Peak vertical force was the only factor associated with the slope of oxygen uptake versus grade (running grade ability; p < 0.01). The slope of oxygen uptake versus grade averaged 0.076 ± 0.278 ((ml/kg/min) / % grade). CONCLUSION: Runners that naturally prefer a higher peak vertical force when running on level ground led to a lower running grade ability (lower oxygen uptake during downhill versus uphill running).

No description available.

Ruptura do tendão calcâneo é uma das lesões tendíneas mais frequentes. Embora a maioria dos trabalhos sugira que o exercício seja benéfico na cicatrização tendínea, não há consenso sobre o efeito do antiinflamatório neste contexto. Trabalhos experimentais tentam reproduzir lesão aguda deste tendão, em diferentes espécies animais. Neste estudo, descrevemos uma técnica de tenotomia completa do tendão calcâneo direito em ratos e, em seguida, avaliamos os efeitos do uso do antiinflamatório e do exercício aeróbico, isoladamente e em combinação, sobre a proliferação celular e o perfil biomecânico do tendão calcâneo, durante o processo de cicatrização após tenotomia. Estudo experimental com 156 ratos machos adultos, da raça Wistar, com idade média de 3 meses e peso médio de 300g. Após anestesia com tiopental e com auxílio da microscopia de luz, foi realizada incisão longitudinal posterior de cinco milímetros, em direção proximal, a partir da tuberosidade posterior do calcâneo da pata direita do rato. Foi feito corte transversal do tendão calcâneo, a sete milímetros da tuberosidade do calcâneo, com preservação do tendão plantar. Utilizamos as técnicas de Hematoxilina e Eosina, Picrosirius-red e Resorcina-fucsina de Weigert para avaliação da cicatrização tendínea e das fibras dos sistemas colágeno e elástico. Após a tenotomia, metade dos animais receberam tenoxicam intramuscular por 7 dias e no 8o dia iniciou-se protocolo de exercício em esteira na metade de cada grupo. Os ratos foram divididos aleatoriamente em 4 grupos de tratamento: A sem antiinflamatório E sem exercício (controle); B com antiinflamatório E com exercício; C sem antiinflamatório E com exercício; D com antiinflamatório E sem exercício. Os animais foram eutanasiados com 1, 2, 4 e 8 semanas após a tenotomia, para avaliação histológica pelo PCNA, e biomecânica através do teste de resistência à tração e da medida do ciclo locomotor. Foram realizados análise de variância, teste de Kruskal-Wallis e o método de Bonferroni, no programa R Project, versão 2.11.1. O tempo cirúrgico médio foi de 1 minuto e 24 segundos, sem complicações observadas até a 8a semana pós-operatória. Observamos proliferação celular e fibrilogênese com duas semanas, e diminuição da celularidade e das fibras elásticas na 8a semana, além de mudanças na organização estrutural do sistema colágeno. Encontramos pico da imunomarcação com PCNA na 2a semana em todos os grupos, exceto no grupo A, cujo pico aconteceu com 1 semana da tenotomia. Evidenciamos resistência à tração significativamente maior (p=0,02) nos ratos submetidos ao exercício, 8 semanas após ruptura. Nos grupos com antiinflamatório, observamos um ciclo locomotor mais estável durante todo o tempo avaliado. Consideramos a técnica cirúrgica experimental de tenotomia completa do tendão calcâneo, realizada com auxílio da microscopia de luz e preservação do tendão plantar, simples, rápida, com sinais de cicatrização tendínea normal e de fácil reprodução em ratos. O exercício aeróbico, iniciado precocemente após tenotomia completa do tendão calcâneo, é significativamente benéfico na sua recuperação biomecânica e o uso combinado com antiinflamatório confere maior estabilidade na marcha, o que pode proteger contra rerruptura tendínea em ratos / Achilles tendon rupture is one of the most frequent tendon injuries. Although most studies have shown the benefits of exercise on tendon regeneration, controversy still exists concerning non-steroidal antinflammatory drug (NSAID) effects in this context. Several experimental models have been used for the study of Achilles tendon injury. In this study, we describe the surgical technique of right Achilles tenotomy in rats and subsequently evaluate the effects of NSAID and aerobic exercise, in an isolated fashion and combined, on cell proliferation and biomechanical aspects of the Achilles tendon after tenotomy. Experimental study with 156 male Wistar rats with an average age of 3 months and with average weight of 300g. Surgical procedures were performed under light microscopy, after anesthesia with thiopental. A five millimeters posterior longitudinal incision was created, proximally directed, starting five millimeters proximal to the posterior calcaneal tuberosity. A complete tenotomy of the Achilles tendon was performed, seven millimeters away from the calcaneal tuberosity. The plantaris tendon was preserved. We used Hematoxilin and Eosin, Picrosirius-red and Weigerts Resorcin-fucsin to observe general tendon healing, especially regarding collagen and elastic fibers. After tenotomy, half of the rats received an intramuscular injection of tenoxican for 7 days and exercise was initiated on the 8th day for half the animals of each group. Rats were randomly divided into four treatment groups: A) no NSAID and no exercise; B) NSAID plus exercise; C) no NSAID, with exercise; D) NSAID and no exercise. Animals were sacrificed at 1, 2, 4 and 8 weeks after the tenotomy and cell proliferation was evaluated by immunohistochemistry for PCNA, biomechanical evaluation was performed with ultimate load and gait cycle analysis was also carried out. We used the test of analysis of variance, the Kruskal-Wallis test and also, Bonferroni method, in the R Project program 2.11.1. The mean operative time was one minute and 24 seconds, without complications observed until the 8th postoperative week. Histological studies showed cellular proliferation and fibrilogenesis at two weeks, with decreased amounts of cellularity and elastic fibers at the 8th week, besides changes in structural organization of collagen fibers. The highest intensity of PCNA immunostaining was found at 2 weeks in all groups except for group A (control) that had the highest intensity at 1 week. Animals submitted to exercise had significantly higher (P = 0.02) ultimate loads at 8 weeks after injury. The animals that received NSAID presented with a more stable gait cycle. The surgical technique described for complete Achilles tenotomy, under light microscopy and sparing the plantaris tendon, is simple and quick, shows signs of normal healing process, and it is easily reproducible in rats. Aerobic exercise, initiated early after a complete Achilles tendon tenotomy, was beneficial to the biomechanical aspects of the tendon during regeneration and the combined use of NSAID improved the gaits characteristics, which could be protective against reruptures

Ruptura do tendão calcâneo é uma das lesões tendíneas mais frequentes. Embora a maioria dos trabalhos sugira que o exercício seja benéfico na cicatrização tendínea, não há consenso sobre o efeito do antiinflamatório neste contexto. Trabalhos experimentais tentam reproduzir lesão aguda deste tendão, em diferentes espécies animais. Neste estudo, descrevemos uma técnica de tenotomia completa do tendão calcâneo direito em ratos e, em seguida, avaliamos os efeitos do uso do antiinflamatório e do exercício aeróbico, isoladamente e em combinação, sobre a proliferação celular e o perfil biomecânico do tendão calcâneo, durante o processo de cicatrização após tenotomia. Estudo experimental com 156 ratos machos adultos, da raça Wistar, com idade média de 3 meses e peso médio de 300g. Após anestesia com tiopental e com auxílio da microscopia de luz, foi realizada incisão longitudinal posterior de cinco milímetros, em direção proximal, a partir da tuberosidade posterior do calcâneo da pata direita do rato. Foi feito corte transversal do tendão calcâneo, a sete milímetros da tuberosidade do calcâneo, com preservação do tendão plantar. Utilizamos as técnicas de Hematoxilina e Eosina, Picrosirius-red e Resorcina-fucsina de Weigert para avaliação da cicatrização tendínea e das fibras dos sistemas colágeno e elástico. Após a tenotomia, metade dos animais receberam tenoxicam intramuscular por 7 dias e no 8o dia iniciou-se protocolo de exercício em esteira na metade de cada grupo. Os ratos foram divididos aleatoriamente em 4 grupos de tratamento: A sem antiinflamatório E sem exercício (controle); B com antiinflamatório E com exercício; C sem antiinflamatório E com exercício; D com antiinflamatório E sem exercício. Os animais foram eutanasiados com 1, 2, 4 e 8 semanas após a tenotomia, para avaliação histológica pelo PCNA, e biomecânica através do teste de resistência à tração e da medida do ciclo locomotor. Foram realizados análise de variância, teste de Kruskal-Wallis e o método de Bonferroni, no programa R Project, versão 2.11.1. O tempo cirúrgico médio foi de 1 minuto e 24 segundos, sem complicações observadas até a 8a semana pós-operatória. Observamos proliferação celular e fibrilogênese com duas semanas, e diminuição da celularidade e das fibras elásticas na 8a semana, além de mudanças na organização estrutural do sistema colágeno. Encontramos pico da imunomarcação com PCNA na 2a semana em todos os grupos, exceto no grupo A, cujo pico aconteceu com 1 semana da tenotomia. Evidenciamos resistência à tração significativamente maior (p=0,02) nos ratos submetidos ao exercício, 8 semanas após ruptura. Nos grupos com antiinflamatório, observamos um ciclo locomotor mais estável durante todo o tempo avaliado. Consideramos a técnica cirúrgica experimental de tenotomia completa do tendão calcâneo, realizada com auxílio da microscopia de luz e preservação do tendão plantar, simples, rápida, com sinais de cicatrização tendínea normal e de fácil reprodução em ratos. O exercício aeróbico, iniciado precocemente após tenotomia completa do tendão calcâneo, é significativamente benéfico na sua recuperação biomecânica e o uso combinado com antiinflamatório confere maior estabilidade na marcha, o que pode proteger contra rerruptura tendínea em ratos / Achilles tendon rupture is one of the most frequent tendon injuries. Although most studies have shown the benefits of exercise on tendon regeneration, controversy still exists concerning non-steroidal antinflammatory drug (NSAID) effects in this context. Several experimental models have been used for the study of Achilles tendon injury. In this study, we describe the surgical technique of right Achilles tenotomy in rats and subsequently evaluate the effects of NSAID and aerobic exercise, in an isolated fashion and combined, on cell proliferation and biomechanical aspects of the Achilles tendon after tenotomy. Experimental study with 156 male Wistar rats with an average age of 3 months and with average weight of 300g. Surgical procedures were performed under light microscopy, after anesthesia with thiopental. A five millimeters posterior longitudinal incision was created, proximally directed, starting five millimeters proximal to the posterior calcaneal tuberosity. A complete tenotomy of the Achilles tendon was performed, seven millimeters away from the calcaneal tuberosity. The plantaris tendon was preserved. We used Hematoxilin and Eosin, Picrosirius-red and Weigerts Resorcin-fucsin to observe general tendon healing, especially regarding collagen and elastic fibers. After tenotomy, half of the rats received an intramuscular injection of tenoxican for 7 days and exercise was initiated on the 8th day for half the animals of each group. Rats were randomly divided into four treatment groups: A) no NSAID and no exercise; B) NSAID plus exercise; C) no NSAID, with exercise; D) NSAID and no exercise. Animals were sacrificed at 1, 2, 4 and 8 weeks after the tenotomy and cell proliferation was evaluated by immunohistochemistry for PCNA, biomechanical evaluation was performed with ultimate load and gait cycle analysis was also carried out. We used the test of analysis of variance, the Kruskal-Wallis test and also, Bonferroni method, in the R Project program 2.11.1. The mean operative time was one minute and 24 seconds, without complications observed until the 8th postoperative week. Histological studies showed cellular proliferation and fibrilogenesis at two weeks, with decreased amounts of cellularity and elastic fibers at the 8th week, besides changes in structural organization of collagen fibers. The highest intensity of PCNA immunostaining was found at 2 weeks in all groups except for group A (control) that had the highest intensity at 1 week. Animals submitted to exercise had significantly higher (P = 0.02) ultimate loads at 8 weeks after injury. The animals that received NSAID presented with a more stable gait cycle. The surgical technique described for complete Achilles tenotomy, under light microscopy and sparing the plantaris tendon, is simple and quick, shows signs of normal healing process, and it is easily reproducible in rats. Aerobic exercise, initiated early after a complete Achilles tendon tenotomy, was beneficial to the biomechanical aspects of the tendon during regeneration and the combined use of NSAID improved the gaits characteristics, which could be protective against reruptures

Este estudo avaliou a efetividade de uma nova membrana bioabsorvível com propriedades mecânicas e químicas mais adequadas para o uso em tendões. A avaliação foi realizada em coelhos submetidos a reconstrução da porção gastrocnêmia do tendão calcâneo. Foi feita uma avaliação prévia das propriedades mecânicas da membrana com uso de dinamômetro digital que demonstrou capacidade de deformação elástica mínima de 100%. Todos os coelhos foram submetidos a tenotomia e reparo da porção gastrocnêmia do tendão direito, após isso foram randomicamente separados em grupos envelopado com membrana e controle. A extração foi realizada nos seguintes períodos: sete, 14 e 28 dias. A avaliação foi realizada através da macroscopia, histologia, mensuração objetiva do colágeno à luz polarizada pelo image-J®, mensuração de glicosaminoglicanos sulfatados e expressão gênica de proteoglicanos. Na avaliação macroscópica o grupo com membrana apresentou menos aderência e melhor direcionamento das fibras e tecido mais homogêneo em 14 e 28 dias, p=0,02 e 0,03 respectivamente. Na histologia a Classificação de Watkins modificada apresentou as seguintes médias: 14,67±0,42 membrana e 12,67±0,56 sem membrana, p=0,03 em 14 dias, e 19,88±0,83 membrana e 17,25±0,62 sem membrana, p=0,02 em 28 dias. Na mensuração do colágeno as médias dos valores de cinza(mvc) o colágeno tipo III foram de 17,97±1,83 membrana e 12,63±1,07 sem membrana p=0,03 em 14 dias. Para o colágeno tipo I as médias foram de 2,41±0,33mvc membrana e 1,31±0,18mvc sem membrana p=0,01 em 14 dias e 7,30±0,63mvc membrana e 2,92±0,32mvc sem membrana p < 0,0001 em 28 dias. A média dos GAGs foi avaliada em três porções do tendão, proximal, central e distal, em ug/mg de tecido seco. Em sete dias apresentou diferença significativa apenas na porção distal 0,80±0,04 com e 0,38±0,04 sem membrana para condroitin-sulfato em 14 dias não apresentou diferenças entre os grupos. O dermatan-sulfato apresentou diferença estatisticamente significante em 7 dias apenas na porção central 0,42±0,09 com membrana e 1,29±0,67 sem membrana p=0,02. Em 14 dias não foram observadas diferenças entre os grupos. Houve grande variabilidade na expressão gênica no teste das amostras com beta-Actina e GAPDH levando a resultados inconclusivos ou não variação entre os grupos que pode sugerir não variabilidade na expressão gênica dos GAGs no período de 28 dias. Os dados fornecidos por esse trabalho mostram que a envelopagem com a membrana bioabsorvível promoveu aceleração dos processos cicatriciais da porção gastrocnêmia do tendão calcâneo de coelhos / This study assessed the effectiveness of a new absorbable membrane, that presents mechanical and chemical features more suitable to tendons, in rabbit tendons. Before the animal model assessments a mechanical study of the membrane was carried out demonstrating that the minimal capability for elastic deformation of the membrane was more than 100%. All rabbits underwent to tenotomy and reconstruction of the right gastrocnius tendons, thereafter they were randomly divided in tendon wrapped by the membrane and control groups. Extraction was performed in the following periods of time: seven, 14 and 28 days. Assessments used macroscopy, histology, objective collagen assessment by using polarized light and Image-J® program in mean of gray values(mgv), sulphated glycosaminoglycans, genetic expression of proteoglycans. In the macroscopic 14 and 21-day assessments the membrane group presented less adherences p=0.02 and p=0.03 respectively. The modified Watkins classification: 14,67±0,42 membrane and 12,67±0,56 without membrane p=0,03 for 14 days; 19,88±0,83 membrane and 17,25±0,62 without membrane p=0,02 for 28 days. The type III collagen were 17,97±1,83 membrane and 12,63±1,07 without membrane p=0,029 for 14 days. For type I collagen were 2,41±0,33 membrane and 1,31±0,18 without membrane p=0,01 for 14 days and 7,30±0,63 memebrane and 2,92±0,32 without membrane p < 0,0001 for 28 days. The glycosaminoglycans were measured in 3 tendon portions, distal, central and proximal, by using ug/mg of dry tissue. In seven days just the distal part presented statistical differences 0,80±0,04 membrane and 0,38±0,04 without membrane, for 14 days no differences were found for Chondroitin-Sulphate. For Dermatan-Sulphate the central part of the tendon 0,42±0,09 and 1,29±0,67 p=0,02, for 14 days no differences were found. There was high variability for beta-actin and GAPDH for the samples in 28 days with inconclusive results that may mean no variability in gene expression of GAGs at this time period. Results as mentioned above demonstrated that the wrapped tendons by the new membrane presented acceleration in the healing processes for gastrocnemius tendons of New Zealand Rabbits

O objetivo deste estudo foi avaliar o efeito dos tempos de aplicação 3, 4 e 5 minutos por ERA do ultrassom terapêutico (UST) na organização das fibras de colágeno em lesão do tendão do calcâneo de ratos. Foram utilizados quarenta ratos machos Wistar, dos quais 32 sofreram tenotomia total do tendão do calcâneo e foram divididos em 5 grupos: GC, sem tenotomia e tratamento; GT, com tenotomia e sem tratamento; UST3, UST4 e UST5 submetidos à tenotomia e tratados com UST nos tempos de 3, 4 e 5 minutos por área de radiação efetiva respectivamente. Os animais foram submetidos à primeira aplicação do UST foi 24 horas após a cirurgia de tenotomia. A irradiação ultrassônica foi aplicada com os seguintes parâmetros: 1 MHz, modo pulsado com 20% do ciclo de trabalho (2 ms de emissão / 8 ms de intervalo), frequência de 100 Hz, 0,5 W / cm² de intensidade e ERA de 0,5 cm². A aplicação foi realizada 1x/dia. Os animais foram sacrificados após a 10ª sessão de tratamento, no 12º dia pós-operatório. Os tendões foram retirados cirurgicamente para análise da organização das fibras colágenas através do método de birrefringência (retardo óptico - OR). As fibras colágenas mostraram melhor agregação e organização no grupo UST3, UST4 e UST5 quando comparado ao GT (p<0.05) e o UST5 apresentou melhor resposta na comparação intergrupos. Conclui-se que o UST, aplicado no tempo de 5 minutos por área de radiação efetiva, apresentou a melhor dose-resposta quanto à organização das fibras colágenas no reparo tecidual de tendões de ratos / The aim of this study was to evaluate the effect of application times 3, 4 and 5 minutes ERA of therapeutic ultrasound in the organization of the collagen fibers in rat calcaneal tendon injury. Forty male Wistar rats were used, of which 32 underwent complete tenotomy of the calcaneal tendon and were divided into 5 groups: GC without tenotomy and treatment; GT tenotomy with and without treatment; UST3, UST4 UST5 and submitted to tenotomy treated with therapeutic ultrasound at times 3, 4 and 5 minutes per effective radiating area respectively. The animals were submitted to the first application of therapy US tenotomy 24 hours after surgery. Ultrasonic irradiation was applied with the following parameters: 1 MHz, pulsed mode at 20% duty cycle (2ms transmission / 8 ms interval), frequency 100 Hz, 0.5 W / cm² intensity and ERA 0.5 cm². The application was performed 1x / day. The animals were sacrificed after the 10th treatment session, on the 12th postoperative day. The tendons were surgically removed for analysis of the organization of the collagen fibers through birefringence method (optical delay - OR). The collagen fibers showed better aggregation and organization in group UST3, UST4 and UST5 when compared to the GT (p <0.05) and UST5 showed better response in the intergroup comparison. We conclude that the UST, applied in time of 5 minutes for effective radiation area, presented the best dose-response as the organization of the collagen fibers in tissue repair of rat tendons