Use of amoxicillin for the prevention postoperative complications in experimetal traumatology

Introduction: Nowaday using an antibiotic therapy in traumatology is very actual. When the healing of an open fracture is performed by using intarmedullary osteosynthesis, this includes the possibility of bacterial infection penetration. Bacteria produce a virulence-related polysaccharide exocellular slime (the glycocalyx), which preferentially adheres to the surfaces of implant. This biofilm resists antibiotic penetration and provides a degree of protection from antibodies and macrophages (A.Gristina, 1984). Often Staphylococcus spp. bacteria are the cause of osteomyelitis. To prevent the postoperative complications antibiotics of a broad spectrum: cephalosporins, aminoglycosides, clindamycin, fluoroquinolones, amoxicillin-clavulanic acid are used. Slatter, 2003). 15% amoxicillin has a broad action spectrum and has a long time of effect (48 h). The use of penicillins (amoxicillin) in rats is limited because rats are hypersensitive (anaphylaxis in repeated application) and amoxicillin can cause enterotoxemia. The aim of our research was to emphasize the opportunity of using amoxicillin in preventing the postoperative complications after intramedullary osteosynthesis. Methods: Female Wistar rats (N=27) were used in the experiment. In all the cases an open fracture of tibia middle third was made. After skin incision of the internal surface of the shin an approach to tibia was performed. Then tibia was fractured in the middle third. Healing of fracture was made by using K-wire (intramedullary osteosyntesis) with different covers: steel (n=9), calcium phosphatis (n=9), hydroxyapatite (n=9). To prevent infectious complications after surgery amoxicillin 15% (15 mg/kg intramuscular) was once injected. Control of animal condition and suture condition was done daily for 35 days. Furthermore X-ray examination of the fracture zone on the 14th and 35th days carried out. Results: There were no infectious complications in all experimental groups during the postoperative period. There were no cases of enterotoxemia. During the first week edema of the operating shin was observed. On the 8th day after surgery all rats moved freely and stepped on the operated paw. X-ray showed absence of osteomyelitis signs on the 14th and 35th days after surgery. Conclusions: This investigation shows that 1 injection of amoxicillin (15 mg/kg intramuscular) is advisable for the prevention of infectious postoperative complications in rats with open bone fracture. This drug is easy to be used and not expensive