Chronic infections following posterior fusion are relatively uncommon. They develop in a previous asymptomatic patient at a distant time from the surgery. Chronic infections arise from direct inoculation or hematogenous seeding. To eradicate a chronic infection, the pathogens, biofilm, non-viable tissues, adherence on surfaces, and instrumentation must be removed. The appropriate antibiotherapy is used in a short (4 weeks) or long protocol (9 weeks). Some patients may need repeated surgeries (leaving the instrumentation in situ) to avoid progressive deformity or symptomatic pseudoarthrosis in cases of implant removal.