First Clinical Experience With Thermal-Sprayed Silver Oxide–Containing Hydroxyapatite Coating Implant

Abstract Background Prosthetic joint infection is a serious complication of implant therapy. To prevent prosthetic joint infection, we previously reported the features of silver oxide–containing hydroxyapatite (Ag-HA), which was prepared by mixing silver (a metal with antimicrobial activity) with HA. In this study, we evaluated the potential issues of total hip arthroplasty (THA) with an Ag-HA–coated implant. Methods We prepared an implant for THA that was coated with Ag-HA. In this study, the implant contained silver at a maximum quantity of 2.9 mg/implant. In this prospective interventional study, we performed THA with this implant in 20 patients and investigated the effects of silver. Results Blood silver levels peaked at 2 weeks after THA and gradually decreased thereafter. The highest blood silver level recorded during the postoperative follow-up was 6.0 ng/mL, which was within the normal range. The Harris Hip Scores increased in all cases, and activities of daily living improved markedly after THA with Ag-HA–coated implants. Implant failure was absent on radiography. No adverse reaction to silver was noted, and argyria was not observed in any case. No patients have developed infection after surgery. Conclusion This is the first clinical study of Ag-HA–coated implants in THA. Our Ag-HA–coated implants markedly improved patients' activities of daily living without causing any adverse reactions attributable to silver in the human body. Ag-HA is expected to reduce postoperative infections and prevent decreased quality of life in patients undergoing prosthetic arthroplasty, thus leading to more favorable outcomes.