Infection with Spinal Instrumentation: A 20-Year, Single-Institution Experience with Review of Pathogenesis, Diagnosis, Prevention, and Management

OBJECTIVE AND IMPORTANCE: Instrumentation has become an integral component in the management of various spinal pathologies. The rate of infection varies from 2% to 20% of all instrumented spinal procedures. Postoperative spinal implant infection places patients at risk for pseudo-arthrosis, correction loss, spondylodiscitis, and adverse neurological sequelae and increases health-care costs. MATERIALS AND METHODS: We performed a cohort study of 1065 patients who underwent instrumented spinal procedures in our institution between 1995 and 2014. Fifty-one patients (4.79%) contracted postoperative spinal infection. Isolated bacterial species, infection severity, diagnosis/treatment timing, surgical/medical strategy treatment, and patient's medical background were evaluated to assess their relationship with management outcome. RESULTS: Multiple risk factors for postoperative spinal infection were identified. Infections may be early or delayed. C-reactive protein and magnetic resonance imaging are important diagnostic tools. Prompt diagnosis and aggressive therapy (debridement and parenteral antibiotics) were responsible for implant preservation in 49 of 51 cases, whereas implant removal noted in two cases was attributed to delayed treatment and uncontrolled infection with implant loosening or late infection with spondylodesis. Infection in the setting of instrumentation is more difficult to diagnose and treat due to biofilm. CONCLUSION: Retention of the mechanically sound implants in early-onset infection permits fusion to occur, whereas delayed treatment and multiple comorbidities will most likely result in a lack of effectiveness in eradicating the infecting pathogens. An improved understanding of the role of biofilm and the development of newer spinal implants has provided insight into the pathogenesis and management of infected spinal implants. It is important to accurately identify and treat postoperative spinal infections. The treatment is multimodal and prolonged.