The effects of cephalexin on fracture healing in a rat femur fracture model

Abstract

Objectives

The aim of this study was to examine the effects of cephalexin on the fracture union histomorphometrically, radiologically, biomechanically, immunohistochemically, and histopathologically in a rat femur fracture model and to evaluate the effects of the antibiotics to be used in the prophylaxis of fracture infection on the union of the fracture.

Materials and methods

A total of 48 male Wistar rats were divided into four groups as two-week control (C2) and cephalexin (CEP2) and four-week control (C4) and cephalexin (CEP4). After establishment of standard fracture model on right femurs, 60 mg/kg/day of cephalexin was applied to CEP2 and CEP4 by oral gavage. Radiological, biomechanical, histopathological, immunohistochemical, and histomorphometric examinations were performed on amputated femurs.

Results

Callus volume of CEP4 group significantly increased compared to CEP2 group (p=0.005), while no significant difference was found in the bone mineral density and callus/bone volume among the groups (p>0.05). There was no significant difference in flexural strength between the C4 and CEP4 groups (p=0.093). Histological healing scores increased from Week 2 to Week 4 (p=0.002) and inflammation scores decreased in both control and cephalexin groups (p=0.010 and p=0.008); however, no significant difference was found in healing and inflammation scores (p>0.05). The CD34+ immunoreactivity in the CEP2 group was significantly higher than the C2 group (p=0.029). Collagen type III level was significantly lower in the CEP2 and CEP4 groups compared to the corresponding control groups (p=0.008 and p=0.016, respectively).

Conclusion

Cephalexin did not exert any radiological, histopathological, histomorphometric, biomechanical, and immunohistochemical adverse effects on the femoral fracture healing model in rats; however, it showed positive effects on CD34 and Collagen type III levels. Based on these findings, antibiotherapy with cephalexin may be considered as a safe treatment for fracture union.