Salvage of instrumented lumbar fusions complicated by surgical wound infection

Study Design. This study retrospectively reviewed instrumented lumbar fusions complicated by surgical wound infection and managed by a protocol including antibiotic impregnated beads. Objective. To evaluate the potential for an acceptable clinical outcome in cases of instrumented lumbar fusion complicated by wound infection. Summary of Background Data. Initial studies of pedicle screw instrumentation suggested an increased infection rate versus noninstrumented fusion. The presence of a metallic implant also complicates wound management. Methods. Eight hundred fifty-eight instrumented fusions were reviewed with 22 (2.6%) deep wound infections identified. Analysis included preoperative risk factors, surgical procedure, postoperative course, and clinical outcome. Results. Nineteen patients (mean age, 55 years) were reviewed at a minimum of 1 year after surgery. Sixteen (83%) reported significant preoperative health problems. Forty-seven percent of the patients had three- and four-level fusions. Mean operative time was 342 minutes. Mean estimated blood loss was 1620 mL. Infection was diagnosed at an average of 16 days after surgery with wound drainage as the most common presenting feature. Patients underwent between two and 10 (mean, 4.7) irrigation procedures. Seven patients had other significant noninfectious complications. At follow-up evaluation, no patient had recurrence of infection. By comparison, to preoperative symptoms, 15 patients were improved, three were unchanged, and one deteriorated. Fusion was apparently solid in 14 patients, probable in four patients, and nonunion occurred in one patient. Conclusion. Although wound infection is a significant complication, this study suggests that aggressive surgical management can result in preservation of an adequate fusion rate and maintenance of an acceptable postoperative outcome.