Authors compared the effectiveness of platelet-rich plasma (PRP) and hyaluronic acid (HA) intra-articular injections as mono-therapeutic options for primary knee osteoarthritis (KOA). They also ascertained if the clinical outcomes were related to changes in the ultrasonography structural appearance. Findings suggested the effectiveness of intra-articular injection of PRP that reduced pain and improved functional status in patients having KOA. Experts noted an association of the clinical outcomes of the intra-articular injections of PRP with improved synovial hypertrophy and vascularity scores and less effusion.