Evaluation of possible infection
The presence of bacteria in an inflammatory wound exudate is proof of infection. Often this is most readily obtained by sterile aspiration of the wound, or preferably by surgical exploration. Microscopic examination (Gram’s stain) of the exudate, and appropriate microbiological cultures may provide evidence of bacterial presence. It has to be borne in mind, however, that there may be few planktonic bacteria in the wound and that most bacteria may be trapped in biofilms (see
Prior antibiotic treatment may interfere with microbiological studies. Occasionally, increasing inflammation is evident without recoverable bacteria, but infection must be assumed if the clinical indicators are strong.
Systemic signs of inflammation, often associated with infection, are provided by several laboratory studies (see below). By themselves, none of these proves, or excludes, infection. The diagnosis of such infections is dynamic and based on serial clinical and laboratory observations. It is the duty of any fracture surgeon to monitor each patient closely for this serious complication.