Wound infections following posterior spinal instrumentation for paralytic scoliosis

Abstract

Objectives: To investigate in a prospective study the infection rate, the bacteriology and the outcome of wound infections following posterior spinal instrumentation in children and young adolescents during 1993-96. Methods: Fifty patients, who underwent spinal instrumentation because of paralytic scoliotic deformity, were followed by the surgeon, the clinical microbiologist and the infection control nurse. In those patients with clinical and laboratory findings suggesting wound infection, multiple swabs and tissue biopsies were obtained from deep within the infected wound and were cultured on appropriate media. Microorganisms were identified by conventional methods. Results: Ten of 50 patients (20%) developed early deep wound infections, most of them polymicrobial, 3-9 days after the operation. Coagulase-negative staphylococci (70.0%), Enterobacteriaceae (17.3%), anaerobes (5.4%) and Staphylococcus aureus (3.7%) were isolated from the wound specimens. S. epidermidis strains were the predominant isolates. All coagulase-negative staphylococci were multiresistant to β-lactams, aminoglycosides, fusidic acid and co-trimoxazole, while most of them were susceptible to rifampicin and quinolones. All wounds healed uneventfully with aggressive debridement and prolonged antimicrobial therapy. Conclusions: Postoperative wound infection is a significant complication of spinal instrumentation. Multiresistant coagulase-negative staphylococci are the predominant pathogens. Successful treatment includes wound debridement and prolonged antimicrobial therapy.