Two consecutive deep sinus tract cultures predict the pathogen of osteomyelitis.
OBJECTIVE
The value of non-bone microbiological cultures in the diagnosis of osteomyelitis with sinus tract is not clear. We aimed to establish the concordance between deep sinus tract cultures and bone cultures in cases of osteomyelitis with a cutaneous fistula.


METHODS
This was a non-randomized, prospective diagnostic trial at the Orthopedic Service of the University Hospital of Geneva. Each patient with osteomyelitis with a cutaneous sinus tract had four microbiological samples taken: two consecutive sinus tract cultures with bone contact at different times (samples A-1 and A-2), surgical bone biopsy performed through the sinus tract (sample B), and a surgical bone biopsy performed through an uninfected area outside the sinus tract (sample C), the latter considered as the 'gold standard'.


RESULTS
One hundred and forty-one patients with 154 episodes of osteomyelitis were included in the study. When both sinus tract cultures yielded the same microorganism (86.4%), the concordance between both samples A and sample C was 96%. In the case of identical sinus tract culture infections, sensitivity was 91%, specificity 86%, and accuracy 90%. The accuracy in monomicrobial infections (50%) was higher than in polymicrobial infections (94.3% vs. 78.9%, respectively; p=0.02).


CONCLUSIONS
In cases of monomicrobial osteomyelitis with sinus tract, two concordant tract cultures with bone contact accurately predict the pathogen.
Bernard
Louis
L
Orthopedic Surgery Service, University Hospital of Geneva, 24, Rue Micheli-du-Crest, 1211 Geneva 14, Switzerland.
Uçkay
Ilker
I
Vuagnat
Albert
A
Assal
Mathieu
M
Stern
Richard
R
Rohner
Peter
P
Hoffmeyer
Pierre
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification*; D001842:Bone and Bones / Q000382:microbiology / Q000473:pathology; D018929:Cell Culture Techniques; D017577:Cutaneous Fistula / Q000382:microbiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000175:diagnosis / Q000382:microbiology* / Q000473:pathology; D010256:Paranasal Sinuses / Q000382:microbiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult