Histopathological investigation of the effect of levofloxacin and cephalexin derivative antibiotics on bone healing in experimentally induced fractures in rat tibias

Abstract

This study compared the effects of systemic Levofloxacin and Cephalexin on bone healing in a rat tibial fracture model. The subjects were divided into six groups (n=7 each): healthy control, fracture control, healthy Levofloxacin, healthy Cephalexin, fractured Levofloxacin, and fractured Cephalexin. In total, 42 Sprague-Dawley rats were used. In the fractured groups, a transverse fracture was created in the right tibial diaphysis, and the bone fragments were stabilized with Kirschner wire. No surgical intervention was performed in the healthy control and healthy antibiotic groups. The antibiotic groups received systemic Levofloxacin (25 mg/kg) or Cephalexin (20 mg/kg) three times a week for 4 weeks, starting on the same day as the fractured subjects. At the end of the experimental process, all animals were euthanised. After the decalcification process, the obtained samples were evaluated histopathologically, and bone filling ratio percentages were analyzed using histomorphometric methods. In the statistical analysis, differences between groups were examined using oneway analysis of variance. In cases where the variances were not homogeneous, pairwise comparisons were performed using the Games-Howell post-hoc test. Bone formation ratios (%) showed significant differences between the groups (P < 0.05). In this study, bone formation rates were found to be 90.71 in the healthy control group, 67.86 in the fracture control group, 61 in the fracture cefelaxin group, 51.14 in the fracture levofloxacin group, 90.29 in the healthy cefelaxin group, and 90.43 in the healthy levofloxacin group. While there was no difference in bone formation among the healthy groups, it was determined that bone formation was reduced in the fractured groups. Among the fractured groups, bone formation in the group treated with Levofloxacin was found to be significantly lower compared to the groups treated with only fracture and Cephalexin (P < 0.05). Considering the results of this study, it is thought that levofloxacin, in particular, has a bone formation-suppressing effect.