Safety and Preliminary Clinical Outcomes of Silver Ion-Doped Calcium Phosphate-Coated Orthopedic Implants: A Prospective Pilot Study

Background: Implant-related infections remain a major cause of failure in orthopedic surgery, partly because biofilm formation on implant surfaces limits conventional infection-control strategies. This prospective pilot study evaluated the short-term safety and preliminary anti-infective performance of silver ion-doped calcium phosphate-coated orthopedic implants. Methods: Thirty patients undergoing surgery for lower-extremity fractures received 107 coated implants, including 91 external fixator pins in 14 patients, 10 proximal femoral nails, and 6 partial hip arthroplasty. The primary endpoint was pin-tract infection, while secondary endpoints included liver and kidney function, inflammatory markers, and serum silver concentrations. Results: Pin-tract infection occurred in 4 of 91 pins (4.39%), involving 2 of 14 patients (14.3%) during follow-up. In one patient, the infection resolved, whereas in the other it persisted until pin removal, corresponding to 1 of 14 patients (7.1%) at final outcome. No infections occurred after proximal femoral nailing, whereas two infections developed after partial hip arthroplasties and were successfully treated with implant-retaining debridement and antibiotics. Liver and kidney function remained stable, inflammatory markers decreased over time, and serum silver concentrations remained below the lower detection limit (<0.3506 µg/L). Conclusions: The coating demonstrated a favorable short-term safety profile without evidence of systemic silver toxicity. Its anti-infective effectiveness requires confirmation in larger controlled studies.