Diagnostic Value of FDG-PET in Spinal Hardware Infection

Spinal hardware infections may be difficult to diagnose when structural imaging does not demonstrate loosening or mechanical failure. We report a 63-year-old woman with a remote L5-S1 posterior fusion performed more than 20 years earlier who developed recurrent methicillin-resistant Staphylococcus aureus (MRSA) abscesses in her lower back and chronic draining sinus tracts despite repeated courses of antibiotic therapy. Serial computed tomography (CT) scans demonstrated intact, fused hardware without evidence of loosening. Ongoing infection prompted further evaluation with fluorodeoxyglucose positron emission tomography (FDG-PET), which revealed increased metabolic activity surrounding the spinal instrumentation, consistent with hardware infection. The patient underwent hardware removal followed by 4 weeks of targeted antimicrobial therapy, after which the draining sinus tracts resolved completely. This case highlights the diagnostic value of FDG-PET in suspected spinal hardware infection when conventional imaging is nondiagnostic.