Mackowiak J, et al. - A retrospective analysis of an insurance claims database was designed to compare the medical costs associated with treatments for knee osteoarthritis (OA): intra-articular corticosteroids (ICS) and intra-articular hyaluronic acid (IHA) primarily, and ICS/IHA vs knee arthroplasty (TKA) secondarily. The total allowed medical costs, claims for pre-specified, treatment-related adverse outcomes and costs, and opioid and/or prescription analgesic use and costs were the main outcome measures. Of the 260,828 individuals who selected, 126,831 were taking monotherapy (IHA=3,703, ICS=117,588, TKA = 5,540). The results of this research indicated that individuals in the IHA cohort had lower total medical care costs, fewer adverse outcomes, and lower use/costs of opioids and prescription analgesics vs individuals in the ICS and TKA cohorts. When selecting therapies for patients with knee OA, decreasing total medical care costs and minimizing opioid/analgesic use should be a treatment goal.