Worrying Presence of Asymptomatic Bacterial Colonisation on Implanted Orthopedic Devices

Background Bacterial infection after hardware implantation in orthopedic and trauma surgery is devastating, resulting in increased hospital costs and stays, multiple revision surgeries, and prolonged use of antibiotics. The present study aims to determine whether a symbiotic relationship between the human organism and bacteria in hardware implantation may be present, without clinically evident infection. Materials and methods We studied explanted devices for microbiological analysis, using the sonication technique, from patients who underwent surgical removal of musculoskeletal hardware for mechanical reasons. None of the patients included in the study had clinical or biochemical signs of infection. Results Forty-nine patients were enrolled. Cultures tested positive for bacteria in 42.8% of the 49 patients (21 of 49). In 13 patients, Gram-positive bacteria were isolated, while Gram-negative bacteria were isolated from nine patients. The most frequent bacterial species found was Pseudomonas aeruginosa, with six positive cultures (28.5%). Coagulase-negative staphylococci were isolated from ten implants (47%). Conclusion A pacific coexistence between humans and bacteria is possible following the implantation of metallic devices for trauma or orthopedic ailments. It is still unclear how strong or unstable this equilibrium is.