Previous studies have shown that sonication fluid cultures from removed orthopedic devices improved the microbiological diagnosis of orthopedic implant-associated infections; however, few of these investigations have applied sonication to the removed fracture fixation devices to evaluate its utility for the diagnosis of osteosynthesis-associated infection (OAI). We compared sonication fluid to conventional tissue cultures from 180 subjects with different sizes of plates and screws (n ؍ 156), spinal implants (n ؍ 26), and intramedullary nails (n ؍ 3), of whom 125 and 55 subjects had OAI and noninfected osteosynthesis (NIO), respectively. The sensitivity for detecting OAI was 90.4% for sonication fluid culture and 56.8% for periprosthetic tissue cultures (P < 0.05), and the specificities were 90.9% and 96.4%, respectively. Sonication fluid culture detected more pathogens than peri-implant tissue culture (113 versus 71; P < 0.001), while polymicrobial infections were diagnosed by sonication fluid cultures and tissue cultures in 20.8% and 8% (P < 0.001), respectively. Microbiological diagnosis was achieved exclusively by sonication fluid cultures for 47 (90.4%) subjects, and among them, 18 (38.3%) had previously received antibiotics, whereas in five (9.6%) infected subjects, tissue culture was positive and the sonication fluid culture was negative. Among 39 (31.2%) OAI cases receiving antibiotics, the identification of the organisms occurred in 38.5% and 82.1% of the tissue and sonication fluid cultures, respectively (P < 0.049). We demonstrated that sonication fluid culture from removed osteosyntheses has the potential for improving the microbiological diagnosis of OAI.
Due to the increasing occurrence of trauma and injuries, particularly those associated with road traffic accidents (1), surgical implantation of orthopedic devices for fracture fixations (or osteosynthesis), including intramedullary nails, different size plates, screws, and external fixation pins, have increased. Indeed, the acute management of bone fractures in trauma patients has evolved steadily, and there is an expanded indication for osteosynthesis, with the aim of early stabilization of the fractures. Depending upon the physiological condition of the patient, especially those with unstable polytrauma and significant lower extremity injuries, surgeons must choose the less aggressive external fixation first step for fracture stabilization (2). Once the adequate local wound debridement is ensured, which includes the removal of all dead and infected tissues and the stabilization of the systemic clinical condition of the patient, secondary major osteosynthesis is then performed with either plates and screws or intramedullary nails (3).Following orthopedic surgery, secondary soft tissue and implant-associated bone infections are still the most important negative aspects and limiting factors of success, leading to significant morbidity, including delayed bone union or nonunion, multiple additional debridement, or even amputation. Wound contamin...