Comparative effectiveness of antimicrobial implant surface coatings in preventing orthopaedic implant-associated infections: a network meta-analysis

PURPOSE: Implant-associated infections (IAIs) remain a major challenge in orthopaedic surgery, causing substantial morbidity, mortality, and healthcare costs. Antimicrobial implant coatings have emerged as a promising preventive strategy, but their comparative clinical benefit remains unclear. This study aimed to evaluate the effectiveness of antimicrobial coatings in preventing IAIs and to compare their clinical performance to uncoated implants. METHODS: A systematic review and network meta-analysis was conducted in accordance with PRISMA guidelines. Medline, Embase, Scopus, and Web of Science were systematically searched for comparative studies evaluating antimicrobial implant coatings for the prevention of orthopaedic IAIs. The primary outcome was the incidence of postoperative IAIs, while secondary outcomes included complications, site-specific infections, causative organisms, use of antibiotic prophylaxis, operative time, time to infection, and implant survival. Random-effects network meta-analysis, subgroup analyses, and assessment of publication bias were performed to synthesize and compare treatment effects across coating types. RESULTS: Twenty-six studies encompassing 3,592 patients were included, of whom 1,576 received coated and 2,016 uncoated implants. Coating technologies included Defensive Antibacterial Coating (DAC) hydrogel, gentamicin, iodine, silver, antibiotic-loaded calcium sulfate, and gold-silver-palladium alloy. Overall, infection rates were lower in coated implants (26.9% vs. 73.1%). Network meta-analysis demonstrated that DAC-hydrogel (OR = 0.10, 95% CI: 0.03–0.28, p < 0.001), gentamicin (OR = 0.27, 95% CI: 0.09–0.80, p = 0.018), iodine (OR = 0.34, 95% CI: 0.12–0.95, p = 0.039), and silver (OR = 0.67, 95% CI: 0.48–0.95, p = 0.026) significantly reduced infection risk. Coated implants were also associated with fewer postoperative complications (OR = 0.28, 95% CI: 0.09–0.85, p = 0.025), delayed infection onset (IRR = 0.24, 95% CI: 0.06–0.95, p = 0.042), and no increase in operative time. CONCLUSION: There is enough statistical evidence to suggest that antimicrobial implant coatings may reduce implant-associated infections and postoperative complications without increasing operative time. High-dose local antibiotic carriers, such as DAC-hydrogel and gentamicin, are associated with the largest reductions in infection risk, supporting their potential protective role in high-risk procedures.