This model was developed to determine the prevalence and incidence of knee osteoarthritis (OA) and total knee arthroplasty (TKA) in the USA in 2015 and the potential impact that the intra-articular hyaluronic injection (IA-HA) Euflexxa may have on quality adjusted life years (QALY) in patients with knee OA. Number estimates were obtained from the American Academy of Orthopedic Surgeons (AAOS) and published literature and were distributed by Kellgren-Lawrence (K-L) grade. The IA-HA treatment option Euflexxa was compared to appropriate care, which was defined as all other non-IA-HA treatments.