Biofilm Infection of Orthopedic Implants: Diagnosis, Treatment, and Prevention

Biofilm infection of orthopedic implants is one of the most challenging problems in modern orthopedics and traumatology, as it combines microbial persistence, limited efficacy of systemic antibacterial therapy, chronic inflammation, impaired osseointegration, implant instability, and functional consequences of treatment. Microorganisms attach to the surfaces of endoprostheses, plates, screws, intramedullary rods, spinal systems, and other fixation devices, forming biofilms that are more tolerant to antibiotics and immune responses than free-living bacteria. This review purposed to summarize current data on the pathogenesis, microbiological spectrum, clinical forms, diagnosis, treatment, prevention, and antibiofilm coating strategies for orthopedic implants. A narrative literature search was performed in four bibliographic databases — PubMed, Scopus, Web of Science, and Google Scholar — and six publisher platforms: Elsevier, Springer Nature, Wiley, Oxford Academic, MDPI, and Frontiers. Eleven keyword groups were used in English and Ukrainian, publications from 2014 to 2026 were prioritized, and 37 sources were included after two-stage screening of titles/abstracts and full texts. The analysis showed that periprosthetic joint infection (PJI) and fracture-related infection (FRI) share the same biofilm mechanism but differ clinically because in FRI, the implant is also required to maintain fracture stability. Key diagnostic elements include deep tissue sampling, sonication of removed implants, histology, and standardized PJI/FRI criteria, whereas superficial swabs are insufficient for final therapeutic decision-making. Effective treatment requires surgical source control, stable fixation or implant revision, dead-space management, soft tissue coverage, and systemic and local antimicrobial therapy. The review identified 12 main groups of antibiofilm or antimicrobial coating strategies, including antibiotic-releasing systems, anti-biotic-loaded hydrogels, gentamicin-coated nails, metal-ion coatings, calcium phosphate-/hydroxyapatite-based systems, antimicrobial peptides, chitosan, nanostructured surfaces, and smart pH- or enzyme-responsive coatings. Multifunctional coatings based on bioactive glass, calcium phosphate, hydroxyapatite, silver, antibiotics, hydrogels, or combined systems are especially promising because they can inhibit early bacterial adhesion, reduce biofilm formation, and support osseointegration. However, most available evidence remains preclinical or clinically limited, and further validation is required before routine use in orthopedic traumatology.