Table 1.

Confirmatory and suggestive criteria for diagnosing fracture-related infection (according to Ref. 8, CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HPF, high-power field; PMNs, polymorphonuclear cells; WBC, white blood cell count.).

Confirmatory criteria	Suggestive Criteria
Clinical signs •Sinus tract •Wound breakdown •Purulent drainage or the presence of pus	Clinical signs •Local/systemic (for example, local redness, swelling, fever) •New-onset joint effusion •fever ≥38,3 °C •Persistent, increasing or new-onset wound drainage
Microbiology •Phenotypically indistinguishable pathogens identified by culture from at least two separate deep tissue/implant specimens	Microbiology •Pathogenic microorganism identified from a single deep tissue/implant specimen
Histopathology •Presence of microorganisms in deep tissue specimens, confirmed by using specific staining techniques for bacteria and fungi •Presence of more than five PMNs per HPF in chronic/late-onset cases (for example, fracture non-union)	Radiological and/or nuclear imaging signs •Non-union, implant loosening, bone lysis, sequestra and periosteal bone formation
	Laboratory tests •Increased serum inflammatory markers (ESR, WBC, CRP)