Posttraumatic bacterial infections in extremities before and after osteosynthesis in small animals

Abstract

Posttraumatic osteomyelitis is one of the most serious complications after fracture treatment. Even though first-generation cephalosporins are always recommended as the first choice of antibiotic prophylaxis in orthopaedic surgery, they cannot eradicate all bacteria, which can enter into the fractured bone during orthopaedic procedures. The purpose of this study was to identify bacteria cultured from surgical wounds during osteosynthesis in order to select properly suitable antibiotic prophylaxis in our clinical practice. Our study was performed on 60 patients with long bone fractures operated at the Department of Surgery and Orthopaedics, Small Animal Clinic, University of Veterinary and Pharmaceutical Sciences, Brno. The patients without an antibiotic treatment 24 hours prior to surgery were included in the study. Samples for bacterial culture were collected before and after internal fixation of the fracture. Several factors possibly influencing the risk of infection were evaluated. Patients with severe degree of soft tissue damage and with open fractures were at higher risk of infection before osteosynthesis, whereas the patients younger than one year, with positive cultures before surgery, with plate and screw fixations, with primary bone healing, with abnormal radiographic findings and intramuscularly anesthetized patients were at a significantly higher risk of bacterial infection after the fracture fixation. A high percentage of the bacterial isolates was Pseudomonas aeruginosa resistent to cephalosporins. Although we use cephalosporins prophylactically in all patients undergoing orthopaedic surgery in our clinic, the incidence of postoperative infections was very low. Therefore, it is obvious that the use of cephalosporins as preoperative prophylaxis is sufficient in most cases. In the patients at high risk of osteomyelitis development (polytraumatized or immunosuppressed patients, patients receiving prosthetic joint or large metallic implants), or in the patients where the infection is already present, it is important to know hospital-specific pathogens to select adequate complementary antibiotics (in our case we use cephalosporines together with quinolones such as enrofloxain). This emphasizes the need of epidemiologic studies, specific for each clinic.