Hyaluronic acid and synovial fluid in preventing adhesion formation after tenorrhaphy: An in vivo study on rabbit Achilles tendon / Ácido hialurônico e líquido sinovial na prevenção da formação de aderências após tenorrafia: Um estudo in vivo sobre o tendão de Aquiles de coelho

Peritendinous adhesions are a significant problem in tendon surgery. One of the most preferred methods for preventing adhesion formation is anti-adhesive applications. This study aimed to investigate the efficacy of natural synovial fluid as an alternative viscoelastic agent for preventing adhesion in the healing period compared to hyaluronic acid. Thirty adult New Zealand rabbits were used in the study to form three experimental models. In all groups, a rupture was induced in the Achilles tendons. Following tenorrhaphy, hyaluronic acid was applied in one group and synovial fluid in the other group for anti-adhesive purposes. In the control group, no viscoelastic application was made. Bandage was applied to the operated extremities for three weeks post-operatively. At the end of five weeks, euthanasia was performed on the animals using pentobarbital sodium. Surgical sites in all groups were macroscopically examined for healing status as well as the presence and extent of adhesions. Biomechanical tests and histopathological examinations were then performed on the tendons in all groups. Findings established once again the positive contribution of hyaluronic acid to preventing adhesion formation as well as to healing and tensile strength in tendon surgery. Although, we found that it is possible to use synovial fluid, which is a natural source of hyaluronic acid, as a viscoelastic material, it is not superior to commercial hyaluronic acid preparation.(AU)

Asderências peritendinares são um problema significativo na cirurgia tendínea. Um dos métodos mais empregados para evitar a formação de adesão são as aplicações anti-adesivas. Este estudo tem como objetivo investigar a eficácia do líquido sinovial natural como um agente viscoelástico alternativo para prevenir a adesão no período de cicatrização comparado ao ácido hialurônico. Trinta coelhos adultos da Nova Zelândia foram utilizados no estudo para formar três modelos experimentais. Em todos os grupos, uma ruptura foi induzida nos tendões de Aquiles. Após tenorrafia, o ácido hialurônico foi aplicado em um grupo e o líquido sinovial no outro grupo para fins anti-adesivos. No grupo controle, não foi feita qualquer aplicação viscoelástica. A bandagem foi aplicada às extremidades operadas por três semanas pós-operatório. No final de cinco semanas, a eutanásia foi realizada nos animais utilizando pentobarbital sódico. Os locais cirúrgicos em todos os grupos foram examinados macroscopicamente quanto ao estado de cura, bem como a presença e extensão das aderências. Testes biomecânicos e exames histopatológicos foram realizados nos tendões em todos os grupos. Os achados estabeleceram mais uma vez a contribuição positiva do ácido hialurônico para prevenir a formação de aderências, bem como para a cicatrização e resistência à tração na cirurgia do tendão. Embora se tenha constatado que é possível utilizar fluido sinovial, que é uma fonte natural de ácido hialurónico, como material viscoelástico, não é superior à preparação de ácido hialurónico comercial.(AU)

Effect of ozone and methylprednisolone treatment following crush type sciatic nerve injury

PURPOSE:To assess and compare the histopathological effects of ozone therapy and/or methylprednisolone (MPS) treatment on regeneration after crush type sciatic nerve injury.METHODS:Forty Sprague-Dawley male rats were randomly allocated into four groups. Four groups received the following regimens intraperitoneally every day for 14 days after formation of crush type injury on sciatic nerve: Group I: ozone (20mcg/ml); Group II: methylprednisolone (2mg/kg); Group III: ozone (20 mcg/ml) and methylprednisolone (2mg/kg); Group IV: isotonic saline (0.9%). The histomorphological evaluation was made after biopsies were obtained from the sites of injury.RESULTS:Significant differences were noted between groups in terms of degeneration (p=0.019), nerve sheath cell atrophy (p=0.012), intraneural inflammatory cellular infiltration (p=0.002), perineural granulation tissue formation (p=0.019), perineural vascular proliferation (p=0.004), perineural inflammatory cellular infiltration (p<0.001) and inflammation in peripheral tissue (p=0.006). Degeneration was remarkably low in Group III, while no change in nerve sheath cell was noted in Group II.CONCLUSION:The combined use of methylprednisolone and ozone treatment can have beneficial effects for regeneration after crush type nerve injury.(AU)