ABSTRACT
BACKGROUND: Tendon injury is one of the most frequent injuries in sports activities. TENS is a physical agent used in the treatment of pain but its influence on the tendon's healing process is unclear. OBJECTIVE: To evaluate the influence of TENS on the healing of partial rupture of the Achilles tendon in rats. METHOD: Sixty Wistar rats were submitted to a partial rupture of the Achilles tendon by direct trauma and randomized into six groups (TENS or Sham stimulation) and the time of evaluation (7, 14, and 21 days post-injury). Burst TENS was applied for 30 minutes, 6 days, 100 Hz frequency, 2 Hz burst frequency, 200 µs pulse duration, and 300 ms pulse train duration. Microscopic analyses were performed to quantify the blood vessels and mast cells, birefringence to quantify collagen fiber alignment, and immunohistochemistry to quantify types I and III collagen fibers. RESULTS: A significant interaction was observed for collagen type I (p=0.020) where the TENS group presented lower percentage in 14 days after the lesion (p=0.33). The main group effect showed that the TENS group presented worse collagen fiber alignment (p=0.001) and lower percentage of collagen III (p=0.001) and the main time effect (p=0.001) showed decreased percentage of collagen III at 7 days (p=0.001) and 14 days (p=0.001) after lesion when compared to 21 days. CONCLUSIONS: Burst TENS inhibited collagen I and III production and impaired its alignment during healing of partial rupture of the Achilles tendon in rats.
Subject(s)
Animals , Rats , Achilles Tendon/physiology , Tendon Injuries/physiopathology , Transcutaneous Electric Nerve Stimulation , Collagen/deficiency , Transcutaneous Electric Nerve Stimulation/methods , Rats, WistarABSTRACT
The Achilles tendon is formed by the union of the soleus and gastrocnemius tendons, its function is to perform plantar flexion. The prevalence of its injury is unknown, but has a multifactorial etiology and occurs most frequently in male than female by a 3:1 ratio, mostly between the fourth and fifth decades of life. The mechanisms of injury include increased weight bearing with the knee in extension, sudden and violent dorsiflexion, and direct trauma. With ultrasound tendon ruptures, complete or partial, Achilles tendinopathy and postoperative changes unrelated to inflammatory process are detected. Ultrasound is a safe imaging technique, low-cost and can be performed in real time, with good rates of sensitivity and specificity compared to other techniques...
El tendón de Aquiles está formado por la unión de los tendones de los músculos sóleo y gastrocnemio, cuya función es realizar flexión plantar. La prevalencia de su lesión es desconocida, su etiología es multifactorial, y se presenta con mayor frecuencia en el género masculino que en el femenino en una proporción de 3:1, entre la cuarta y quinta décadas de la vida. Los mecanismos de lesión incluyen incremento en el soporte de peso con la rodilla en extensión, dorsiflexión súbita y violenta y trauma directo. Con la US se detectan rupturas del tendón de Aquiles completas o parciales, tendinopatía y cambios postoperatorios no relacionados a proceso inflamatorio; la US es un método inocuo, de bajo costo y se realiza en tiempo real; tiene buena sensibilidad y especificidad...
Subject(s)
Humans , Achilles Tendon/physiology , Achilles Tendon/physiopathology , Achilles TendonABSTRACT
OBJETIVO: Analisar in vitro, a resposta mecânica de tendões calcâneo bovino, submetidos ao alongamento estático e avaliar a influência do alongamento no evento lesivo.MÉTODOS: Seis grupos de espécimes de tendões calcâneos bovinos (n=10) foram submetidos a alongamento estático: três intervalos (15, 30, 45 segundos) e percentuais de alongamento inicial (2,5 e 3,5%). O grupo controle (n=10) não realizou alongamento prévio. Ao termino do ensaio de alongamento, os espécimes foram submetidos ao ensaio de ruptura.RESULTADOS: Os valores de relaxamento de força apresentaram estabilização a partir do trigésimo segundo (p<0.0001) nos dois níveis de deformação estudados. Foi observado maior relaxamento de força (p<0.0026) e menor tensão de ruptura (p = 0.0123) para o grupo submetido a maior taxa de alongamento percentual (3,5%). Não houve diferença nos parâmetros de ruptura entre os grupos alongamento e controle. As variáveis tempo e percentual de alongamento não apresentaram interação.CONCLUSÃO: Considerando-se o relaxamento de estresse, o intervalo de 30 segundos parece ser o mais efetivo no alongamento de tendões, fato a ser considerado no estabelecimento de novos protocolos clínicos de alongamento. Trabalho experimental.
OBJECTIVE: Analyze in vitro the mechanical response of bovine calcaneus tendons subjected to static stretching in three different intervals (15, 30, 45 s).METHODS: Six groups of bovine calcaneus tendons (n=10) were formed according to the static stretching protocol: three different intervals (15, 30, 45 s) and initial stretching percentage (2.5% and 3.5%). The control group (n=10) did not perform prior stretching. At the end of the stretching tests, the specimens were subjected to stress rupture tests.RESULTS: The values for force relaxation presented stability after the 30th second (p<0.0001) at both levels of deformation. Greater force relaxation (p<0.0026) and the least tensile strength (p=0.0123) was observed in the group that was subjected to the highest stretch percentage (3.5%). No difference was observed between the rupture parameters of the stretch and control groups. The variables, stretch duration and percentage did not demonstrate interaction.CONCLUSION: In relation to force relaxation, the 30 second interval seems to be the most effective when stretching tendons. This fact should be considered when establishing new clinical stretching protocols. Laboratory investigation.
Subject(s)
Animals , Male , Cattle , Biomechanical Phenomena/physiology , Collagen/physiology , Muscle Stretching Exercises/standards , Reaction Time , Rupture , Achilles Tendon/physiology , Dissection , Clinical Trial , Data Interpretation, StatisticalABSTRACT
Las lesiones de los tendones plantean siempre grandes problemas clínicos y terapéuticos, por su importancia funcional y su peculiar cicatrización. El apoyo fisiátrico, específicamente el tratamiento con ultrasonido, ha demostrado ser eficiente en la regeneración del tendón calcáneo. Este trabajo tuvo como objetivo analizar morfológicamente los efectos del uso de ultrasonido continuo en la regeneración post quirúrgica del tendón calcáneo de rata. Se utilizaron 15 ratas albinas, Sprager Dawle. Luego de 48 horas post tenorrafia se comenzó con una sesión diaria de ultrasonido terapéutico con una intensidad de 1W/cm², frecuencia de 3 MHZ, cabezal de 0,5 cm de ERA, por 30 segundos durante 10 días. Las ratas fueron sacrificadas 48 horas después de terminar las aplicaciones de ultrasonido para la extracción y disección del tendón calcáneo del miembro posterior derecho, mientras que el tendón del miembro posterior izquierdo sirvió de control normal. Para fines de comparación morfológica se trabajó con un grupo de ratas control del tratamiento, en el que se provocó la lesión sin aplicar ultrasonido. Las muestras fueron fijadas en formalina tamponada y teñidas con H.E. Los tendones del grupo experimental se encontraron en un estado de regeneración avanzada, cuyos fibroblastos presentaron características morfológicas propias de una célula activa en la síntesis y secreción de matriz extracelular, con un promedio de fibroblastos similar al obtenido en el tendón normal. A su vez, el tendón del grupo sin tratamiento presentó un estado de regeneración tardío. Las fibras colágenas estaban invadidas por tejido conjuntivo y vasos sanguíneos, con un promedio de fibroblastos que triplica al promedio encontrado en el control normal, lo que determinó que el tendón sin aplicación de ultrasonido se encontrara aún en proceso inflamatorio. Este estudio confirma que el uso de ultrasonido continuo genera una rápida proliferación celular en el tendón lesionado de rata, y en consecuencia, a...
Tendon injuries always account for major clinical and therapeutic problems, due to their functional significance and unique healing. Physiatrics support, specifically ultrasound treatment, has been shown to be effective in the regeneration of the calcaneal tendon.The objective of this study was to morphologically analyze the effect of the use of continuous ultrasound in the post surgery regeneration of the calcaneal tendon of the rat. Ten albino, Sprager Dawley rats were used. Following 48 hours of post tenorrhaphy, a daily session of therapeutic ultrasound was initiated, with an intensity of 1W/cm², frequency of 3 MHZ, header at 0.5 cm ERA, per 30 seconds for 10 days. The rats were sacrificed 48 hours after completion of the ultrasound treatments, for the extraction and dissection of the calcaneal tendon of the right posterior member, while the left posterior member was used for normal control. For purposes of morphological comparison a group of control rats for the treatment was used, in which the injury was caused without applying the ultrasound. Samples were fixed in buffered formalin and stained with H.E. The tendons of the experimental group were found to be in an advanced stage of regeneration which fibroblasts presented morphological characteristics of an active cell in the synthesis and secretion of the extracellular matrix, with an average of fibroblasts similar to that obtained in the normal tendon. At the same time, the tendon of the control group in the treatment, presented a later regeneration stage. The collagen fibers were infiltrated by conjunctive tissue and blood vessels, with an average of fibroblasts that tripled the average found in the normal control, which determined that the tendon without the ultrasound treatment was still in an inflammatory process. This study confirms that the use of continuous ultrasound generated a rapid cellular proliferation in the injured tendon of the rat, and consequently accelerates its regeneration.