Investigation of the effects of enoxsaparin sodium and hyperbaric oxygen therapy on healing in rats with achile tendon ruptured

Objective: Tendons can be easily injured acutely or chronically due to repetitive movements, degeneration and trauma. Tendon healing after injury occurs with the formation of fibrotic scar tissue. The structural and mechanical properties of this tissue are weaker than the normal tendon. Some biomaterials have been tried in different studies to make the tendon more robust after healing, skeletal structures have been formed from cells containing fibroblasts, growth factors and cytokines have also been applied exogenously. Tissue engineering through gene and cell therapy has also been used for this purpose. Many substances and factors affecting tendon healing have been examined in previous studies. Low molecular weight heparins (LMWH) are widely used to prevent deep vein thrombosis, which may develop after lower extremity surgery. Although some substances from the LMWH group have been examined as an animal experiment, there is no study on tendon healing of Enoxaparin sodium, which is the most widely used LMWH today. In this study, we aimed to investigate the effects of hyperbaric oxygen therapy and enoxparin sodium on the healing of Achilles tendon rupture, which is known to accelerate bone tissue healing in addition to tendon and soft tissues. Material and Methods: 36 adult female Wistar Albino rats were used in the study. All rats were divided into 4 groups of 9 each. Group 1 was provided with standard care conditions after the experimentally created achilotomy and primary suturing. Group 2 was given enoxaparin sodium subcutaneously at 1mg/kg/day per day for 21 days after achilotomy and primary suturing. Hyperbaric oxygen therapy (1 hour at 2.5 ATA pressure) was applied to Group 3 for 21 days after achilotomy and primary suturing. Group 4 was given both 1mg/kg/day enoxaparin sodium subcutaneously for 21 days after achilotomy and primary suturing, and hyperbaric oxygen therapy (1 hour at 2.5 ATA pressure). After 21 days, the process was completed and the rats were sacrificed. Achilles tendon samples taken were evaluated histopathologically. Results: While there was no significant difference between the groups in terms of acute inflammation (p=0.785) and chronic inflammation (p=0.827) scores, there was a significant difference in neovascularization (p=0.009), proliferation (p<0.001) and fibrosis (p=0.006) scores. Significant difference in neovascularization is observed only between hyperbaric oxygen and enoxaparin sodium+HBO groups (p=0.006), other groups are similar to each other when paired pairs are compared. Significant difference in proliferation occurs in the enoxaparin sodium+HBO group, this group differs significantly from all other groups. It occurs between enoxaparin sodium and enoxaparin sodium+HBO (p<0.001), Hyperbaric oxygen and Enoxaparin sodium+HBO (p=0.017) and control and enoxaparin sodium+HBO(p=0.034) groups, other groups duo are similar to each other when compared. Significant difference in fibrosis is observed between enoxaparin sodium and enoxaparin sodium+HBO (p=0.012) and control and enoxaparin sodium (p=0.046) groups. Other groups are similar when paired with each other. Conclusions: Considering the findings we obtained as a result of our study, the use of enoxaparin sodium and hyperbaric oxygen had a positive effect on the Achilles tendon healing process. Based on these results, we believe that the use of enoxaparin sodium and hyperbaric oxygen therapy after Achilles tendon rupture will be beneficial in the healing process and prevention of complications. Keywords: Achilles tendon rupture, hyperbaric oxygen, enoxaparin sodium, rat