Updated project metadata. This study investigated the effect of intraarticular gold micro particle implants for the treatment of pain and inflammation in KOA. The present open, exploratory, proof-of-concept study investigated whether intraarticular gold ions could act as a KOA treatment option through modulation of inflammatory mediators, pain sensitivity, and central pain mechanisms. The primary aim of this study were 1) to measure the effect on pain and function after intra-articular injection of 20 mg gold microparticles > 20 µm into the KOA joint using the patient’s synovial fluid (SF) as a carrier and 2) measure associated possible proteomic changes in the SF and serum.