Silver-coated megaprostheses in patients at high risk for infection: evaluation of clinical results and silver ion levels in body fluids in a series of 22 patients

Introduction Deep infection is one of the most frequent and harmful complications in megaprostheses. Silver coating was recently introduced for orthopaedic and other internal implants to reduce infection rate due to silver antibacterial effect. Methods From 2010 in infected or high-risk patients, we began to use a modified MegaC System megaprosthesis with an innovative surface modification producing a peripheral silver-added layer of titanium alloy (PorAg). From June 2010 to December 2013, 22 PorAg implants were implanted (10 proximal femur, 8 distal femur, 1 total femur, 3 knee arthrodesis) after infection following previous prosthesis (9) or fracture (6) or in patients at risk for local or general conditions (7). Results Average follow-up was 19 months (1–41). No occurrence or recurrence of infection was detected so far. Urine and blood levels of silver were monitored. At 1 year from surgery, levels of 0.1–1.5 lg/l were detected in urine and levels of 0.24–3.9 lg/l in blood. Higher levels were usually detected in the first months after surgery. No local or systemic side effects related to silver were detectable. Discussion The use of silver coating for internal orthopaedic and vascular implants is spreading due to the promising results followed the first experimental and clinical experiences. In our study, a very satisfying early result was found for infection control with no septic complications in a high risk group of patients, mostly affected by previous infections. The absence of side-effects and the circulating silver levels detected confirm in our experience the safety of silvercoated prostheses. Conclusions Silver coating for mega-prostheses may constitute today an important aid in the treatment of patients at high risk of septic complication. If their effectiveness is confirmed in reducing the incidence of postoperative infections, the higher cost of implants is compensated not only from better quality of patients’ life, but also by reduction overall costs for Healthcare System. Longer follow-up is needed both to confirm long-term results and to monitor silver levels in body fluids on the long term.