In the diagnosis of early infections, x-ray imaging plays a negligible role. Radiographic findings of infection are usually not evident until at least 2 weeks after the onset of infection, even though bone involvement has already occurred.
Imaging becomes important in the later stages of infection. It is helpful to examine serial x-rays for progressive changes that could suggest infection.
Radiographic signs are neither sensitive nor specific for infection; e.g., radiographic evidence of implant loosening may be present as a result of instability, infection, or both.