Neglected fracture-site infections may manifest themselves intermittently, with episodes of symptomatic inflammation (pain, redness, swelling and perhaps the development of a discharging sinus), separated by periods of reasonable comfort and function.
If the fracture is united and the patient is functional, the primary goal is to heal the infection. Recurrence is usually due to a persisting collection of biofilm bacteria, typically around fixation hardware, or to the presence of necrotic bone. A necrotic fragment (sequestrum) may lie adjacent to, or within, the previously fractured bone. If hardware is present, its removal is almost always essential. A sequestrum may be hidden under a retained plate, or be hard to find adjacent to an intramedullary nail.
If a sinus is present, it will often lead to the source of recurrent infection. Cross-sectional imaging (CT, or MRI) helps to detect and locate sequestra and necrotic bone. It will be more informative after any hardware has been removed.