Effect of shock waves upon the growth plate in rabbits

OBJECTIVE: To evaluate the effects of shock waves upon the growth plate in rabbits by varying the energy and number of applied waves. MATERIAL AND METHODS: Six groups of five rabbits aged 5 weeks (Total: 30) were studied. OSSATRON (HMT) was used to generate shock waves. Animals were submitted to applications upon the proximal growth plate of the left tibia; the intensity (14, 21,28kV) and number of waves varied (1,000 and 4,000). The right tibia was used as control. Animals were sacrificed after six weeks when measurements of tibia length were taken and the growth plate was microscopically studied. Statistical tests were used to compare measurements of the growth plate area and tibia length with those obtained in the control group, as well as between study groups. RESULTS: In the present study, no statistically significant change was found in the measurements of the growth plate area and tibia length following application of shock waves in either group. A difference in the tibia growth tended to occur between the groups submitted to 1,000 impulses and the groups submitted to 4,000 impulses. However, this difference was not statistically significant. Hematomas were seen in the local of application in groups submitted to higher-energy waves and spontaneously subsided, special care being not required. CONCLUSIONS: The application of shock waves upon the proximal tibia in immature rabbits as described did not have any effect upon the growth plate, as shown by the evaluation methods used in the present study.OBJETIVO: Avaliar os efeitos da aplicação de ondas de choque na placa de crescimento de coelhos, variando a energia e o número de ondas aplicadas. MATERIAL E MÉTODOS: Foram estudados 30 coelhos com idade de cinco semanas divididos em seis grupos. O aparelho gerador de ondas de choque foi o OSSATRON (HMT). Os animais foram submetidos a aplicações na placa de crescimento proximal da tíbia esquerda, variando a intensidade (14, 21,28kV) e o número de ondas (1000 e 4000). A tíbia direita foi usada como controle. Os animais foram sacrificados após seis semanas e sua avaliação foi feita por meio da mensuração do comprimento das tíbias e pela análise microscópica da placa de crescimento. Os resultados de mensuração da área da placa e do comprimento das tíbias foram comparados com o grupo controle e entre os grupos, utilizando-se estudos estatísticos. RESULTADOS: Neste estudo não ocorreram alterações estatisticamente significantes nas medidas da área da placa ou do comprimento da tíbia após a aplicação de ondas de choque em nenhum dos grupos. Foi observada tendência de ocorrer uma diferença de crescimento das tíbias entre os grupos submetidos a 1.000 impulsos e os grupos submetidos a 4.000 impulsos, mas esta diferença não foi considerada significante. Foi observada também a formação de hematoma no local da aplicação nos grupos que receberam ondas com maior energia, evoluindo com regressão espontânea sem necessidade de cuidados especiais. CONCLUSÕES: A aplicação de ondas de choque na região proximal da tíbia de coelhos imaturos, nas formas descritas, não teve nenhum efeito na placa de crescimento, de acordo com os métodos de avaliação usados neste estudo.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Ortopedia e TraumatologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PatologiaUNIFESP, EPM, Depto. de Ortopedia e TraumatologiaUNIFESP, EPM, Depto. de PatologiaSciEL

High-energy extracorporeal shockwave therapy in a patellar tendon animal model: a vascularization-focused study

OBJECTIVE: The aim of this study was to analyze the effect of high-energy extracorporeal shockwave therapy on tendon angiogenesis in the patellar tendons of rabbits. We sought to investigate whether different voltage and number pulses modify the angiogenesis pattern. INTRODUCTION: High-energy extracorporeal shockwave therapy is an option in the treatment of orthopedic diseases such as chronic tendonitis. Despite its potential clinical applicability, there have been few studies on this technique that examine both its clinical effectiveness and its effect on angiogenesis. METHODS: High-energy extracorporeal shockwave therapy was applied at the tibial insertion of the left patellar ligament in 30 rabbits that were separated into six groups that differed in terms of the voltage and number of pulses that were applied by high-energy extracorporeal shockwave therapy. The tibial insertion in the right legs of the animals was used as the control. After six weeks, we performed histological analysis on the region and quantified the number of blood vessels. RESULTS: No significant differences in the number of blood vessels between the left and right patellar tendons were found within groups. Additionally, no significant differences in the number of blood vessels in the left patellar tendons were found between groups. CONCLUSIONS: The application of high-energy extracorporeal shockwave therapy did not cause a change in vascularization in the patellar tendon in rabbits