Non-culture-based Methods to Aide in the Diagnosis of Implant-associated Infection After Fracture Surgery

Implant-associated infection after fracture surgery is an unfortunate reality for patients and physicians that has long-term, far-reaching implications for treatment, functional recovery, and health care costs. Classically, culture-based methods are used for diagnosis, though culture-negative infection is not an uncommon clinical scenario. On the other side, false-positive results can lead to unnecessary antibiotic treatment or surgical intervention. For all parties involved, timely, accurate, and noninvasive diagnostic methods are desirable. It is recognized that bacterial biofilms complicate culture-based diagnostic methods and circumvent the host's immune response and standard treatment modalities, such as antibiotic therapy. Infection may be diagnosed by indirect means, such as measure of host inflammatory response, or direct detection of pathogen presence. Until recently, the Orthopedic Trauma community has not had a standardized definition for fracture-related infection. This definition, along with recent changes in, or the development of, sonication, histopathology, biomarkers, detection of host immune response, and molecular methods for detecting bacterial presence represent progress in using non-culture-based methods to aide in the diagnosis of implant-associated infection after fracture surgery. This review will examine the current state of these emerging technologies. Building on the success over the past decade of our total joint arthroplasty colleagues in diagnosing periprosthetic joint infection, it is expected that these methodologies will improve our ability to diagnose fracture-related infection.