Orthopaedic implant-associated infection (OIAI) is one of the most serious complications in orthopaedic surgery. The number of total hip arthroplasty cases was estimated to increase by 174 % in the US, from 208,600 surgeries in 2005 to 572,000 in 2030 [1]. The number of spine surgeries, such as lumbar interbody fusion, is also increasing, often in elderly patients with complications or compromised immunity [2]; the increase in OIAI is also a major concern [3,4]. OIAIs can be counteracted by enhancing the antimicrobial activity on the implant surface [5]. Silver (Ag) is well-known for its broad antimicrobial spectrum, strong antibacterial activity, and low toxicity. Several studies have reported the safety, low toxicity [6], Ag+ ion release potential [7], antibacterial activity [8], and osteoconductivity-improving [9] properties of silver-containing hydroxyapatite (Ag-HA) coatings developed using a novel thermal spraying approach [7]. Ag-HA-coated antimicrobial implants for total hip arthroplasty [10] and spinal surgery [11] were also developed to prevent OIAIs, and their clinical results were reported. However, the ability of Ag-HA coatings to resist late-onset orthopaedic implant-associated infection (LOIAI) remains unknown. This study aimed to evaluate the long-term Ag+ ion elution and antibacterial properties of Ag-HA coatings through in vitro and in vivo experiments.