The effects of local tranexamic acid on vertebrae fusion: Experimental study in rats

Aim of treatments in spine deformities, fractures, intervertebral disc disorders, spondylolisthesis, to obtain a biomechanically stable spine. The most effective method for achieving this stabilization is spine fusion. Although the pathophysiology of the fusion is better understood with the available facilities, pseudoarthrosis complication can still be encountered. Management of perioperative bleeding is an important issue that should be taken seriously especially in complex and high-risk multilevel spine fusion operations. Previous studies have shown that reduce blood loss in spine surgeries, intravenous (IV) and local TA are effective compared to the control group in parameters such as total blood loss, haemoglobin decline, and need for blood transfusion. The effects of local tranexamic acid, which is frequently used in fusion surgery, on fusion quality are not known. In this study, we aimed to investigate the effect of local tranexamic acid in different doses on experimental fusion model of rat in palpation, radiological and histopathological.In our study, 28 Winstor Albino rats were used. We performed all rats' intertransverse fusion with iliac crest autograft. The groups were selected by using closed envelope method immediately after the surgical procedure. In our study consisting of 4 groups, only fusion was applied to the control group (n = 7). 1 mg / kg tTA was applied to D1 group, 10 mg / kg tTA was applied to D10 group, and 100 mg / kg tTA was administered to D100 group. At the end of the 8th week, the rats were first taken direct graphies by mammography under general anaesthesia. Two animals from the control group died after radiographic examination. The study was continued with 26 rats. The remaining rats were sacrificed. Four independent investigators graded radiological evaluation of the fusion, as intra-interobserver twice with one-month intervals. 3 independent - blind investigators performed manual palpation fusion mass and an independent - blind investigator performed histopathological examination. Statistical analysis of the data was performed.In our study, palpation, radiological and histopathological results were better in the control group compared to the other groups. When the treated groups were evaluated within themselves, it was found that the D1 group was the best according to the palpation results and the fusion decreased with respect to palpation as the dose was increased (p <0.005). When the radiological examinations were evaluated between the treated groups, there was no difference between the D1, D10 and D100 groups. Histopathological examination revealed mature bone marrow in all rats and showed that fusion occurred and bone healing continued. Union of D1 group was better than the other D10 and D100 groups but no difference was found in the other variables.In this study, we found that local tranexamic acid have a negative effect on fusion. Also the use of different doses has a macroscopically negative effect and do not make any difference in radiological and histological.