Diagnosis of fracture-related infection in patients without clinicalconfirmatory criteria: an international retrospective cohort study

Background: fracture-related infection (FRI) remains a seriouscomplication in orthopedic trauma. To standardize daily clinical practice,a consensus definition was established, based on confirmatory and suggestivecriteria. In the presence of clinical confirmatory criteria, the diagnosisof an FRI is evident, and treatment can be started. However, if thesecriteria are absent, the decision to surgically collect deep tissue culturescan only be based on suggestive criteria. The primary study aim was tocharacterize the subpopulation of FRI patients presenting without clinicalconfirmatory criteria (fistula, sinus, wound breakdown, purulent wounddrainage or presence of pus during surgery). The secondary aims were todescribe the prevalence of the diagnostic criteria for FRI and present themicrobiological characteristics, both for the entire FRI population. Methods: a multicenter, retrospective cohort study was performed, reportingthe demographic, clinical and microbiological characteristics of 609patients (with 613 fractures) who were treated for FRI based on therecommendations of a multidisciplinary team. Patients were divided in threegroups, including the total population and two subgroups of patientspresenting with or without clinical confirmatory criteria. Results: clinical and microbiological confirmatory criteria were present in 77 %and 87 % of the included fractures, respectively. Ofpatients, 23 % presented without clinical confirmatory criteria, and they mostlydisplayed one (31 %) or two (23 %) suggestive clinical criteria(redness, swelling, warmth, pain, fever, new-onset joint effusion,persisting/increasing/new-onset wound drainage). The prevalence of anysuggestive clinical, radiological or laboratory criteria in this subgroupwas 85 %, 55 % and 97 %, respectively. Most infections weremonomicrobial (64 %) and caused by Staphylococcus aureus. Conclusion: clinicalconfirmatory criteria were absent in 23 % of the FRIs. In these cases, thedecision to operatively collect deep tissue cultures was based on clinical,radiological and laboratory suggestive criteria. The combined use of thesecriteria should guide physicians in the management pathway of FRI. Furtherresearch is needed to provide guidelines on the decision to proceed withsurgery when only these suggestive criteria are present.