A Comparative Study of Bacteriological Culture Results Using Swab and Tissue in Open Fractures: A Pilot Study

The role of perioperative cultures to identify infection in open fractures has been doubtful. The method of sampling for cultures in open fractures includes swab or tissue collection. However, the efficacy of either of these two techniques has not been compared in the setting of an acute open fracture. We conducted a study to compare the bacteriological culture results between the two techniques.

A pilot study was done at our institution, where all type 2, 3A, and 3B open fractures admitted in the emergency and operated for debridement and stabilization were included in the study. Intraoperatively, after debridement of the wound, swab and tissue specimens were collected and sent to the same laboratory. The results of the cultures were then collected for comparison after the necessary incubation period. Follow-up of outpatient records was also done to see its clinical significance.

A total of 30 samples of swab and tissue cultures collected post-debridement of acute open fractures in the operation theater were studied. Only 13 samples grew an organism either in swab/tissue culture or both. Nine tissue samples and eight swab samples showed growth. In four cases, both swab and tissue showed growth, but the same organism grew in only one instance. The other three cases showing growth in both tissue and swab had different organisms. Statistically, the kappa coefficient was found to be 0.26 and the agreement between swab and tissue culture was found fair. However, the kappa did not account for the species of the organisms. Tissue samples showed more number of specific organism growing in them, compared to swab culture samples.

The ideal technique of taking samples for culture in acute open fractures is uncertain. Tissue culture may be better in isolating specific organisms in an acute open fracture wound. However, it is uncertain if the same organism may cause infection.