Praxis Medical Insights

Diagnostic Criteria

The FRI Consensus Group defines fracture-related infection (FRI) by specific diagnostic criteria, which categorizes features as either confirmatory or suggestive of infection, including the presence of a sinus tract, wound breakdown, or purulent drainage around the fracture site 1, 2
Confirmatory criteria for FRI diagnosis include clinical signs such as presence of a sinus tract communicating with the bone or implant, wound breakdown exposing the bone or implant, and purulent drainage or presence of pus around the fracture site 1, 3, 4, 5
Microbiological evidence, such as phenotypically indistinguishable pathogens identified from at least 2 separate deep tissue/implant specimens, is also a confirmatory criterion for FRI diagnosis 1, 2, 5
Histopathological evidence, including the presence of microorganisms in deep tissue specimens confirmed using specific staining techniques, is another confirmatory criterion for FRI diagnosis 1, 5, 6

Suggestive criteria for FRI diagnosis include clinical signs such as local or systemic signs like pain, redness, swelling, or fever, new-onset joint effusion, and persistent or increasing wound drainage 1, 2, 3, 4, 5
Laboratory signs, such as increased serum inflammatory markers, are also suggestive of FRI 1, 6, 7

Imaging findings like implant loosening, bone lysis, and periosteal bone formation are suggestive but not confirmatory of FRI 1, 6
Individual serum inflammatory markers are only suggestive and not conclusive for FRI diagnosis 1, 6

Relying solely on time-based classifications may lead to misdiagnosis of FRI 1, 2
Inflammatory markers may paradoxically increase within the first few weeks of diagnosis despite clinical improvement 7
Overreliance on individual laboratory markers without clinical correlation can lead to misdiagnosis of FRI 1, 6