Histological assessment of the presence or absence of infection in fracture non-union.
BACKGROUND
Infection is a major cause of non-unions. Infection is not always evident clinically, nor on bacteriological analysis. If it is untreated, non-union treatment may fail.


OBJECTIVE
To establish whether histological analysis is of value as an adjunct to microbiology in establishing the diagnosis of infection.


METHODS
Sixty patients who had both bacteriological and histological analysis of their non-unions were studied. Infection was indicated by an acute inflammatory response. In 45 of the 60 fractures, microbiological and clinical diagnoses were in agreement; in this subset the histology results were compared to the established diagnoses.


RESULTS
The histological diagnosis for the 45 fractures in the group with a definite diagnosis gave four false negatives but no false positives. This represents a sensitivity of 87.1%, (95% CI, 70-96%) and a 100% specificity (95% CI, 77-100%). The overall accuracy was 91.1%. (95% CI, 79-98%) The predictive value of a positive test was 100% and of a negative test was 77.8%. In 25% of the series a definite diagnosis could not be made with purely clinical and microbiological information; with the additional histological information it was possible to determine the infection status of the non-union.


CONCLUSIONS
Histology is of particular use when the microbiology is negative or equivocal.
Simpson
A H R W
AH
Department of Orthopaedic Surgery and Trauma, Princess Margaret Rose Hospital, Frogston Road, Edinburgh ED10 7ED, UK. hamish.simpson@ed.ac.uk
Wood
M K
MK
Athanasou
N A
NA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000150:complications / Q000175:diagnosis / Q000473:pathology*; D001431:Bacteriological Techniques; D002648:Child; D002675:Child, Preschool; D005260:Female; D005599:Fractures, Ununited / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020556:Neutrophil Infiltration; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013530:Surgical Wound Infection / Q000150:complications / Q000175:diagnosis / Q000473:pathology*