RESUMO
Osteoarthritis of the knee affects many Americans. With the aging of the population and increasing comorbidities (eg, obesity, diabetes, hypertension, heart disease), the use of oral or topical NSAIDs is often contraindicated. Injectable treatment options are advantageous because of the ability to decrease or avoid the unwanted systematic adverse effects of NSAIDs. Injectable treatment options for osteoarthritis of the knee go back to the 1950s, beginning with corticosteroids, which remain widely used despite concerns that they may have adverse effects on articular chondrocytes and short duration of efficacy. The recent (FDA approval in 2017) introduction of a sustained-release corticosteroid (triamcinolone acetonide extended-release) offers significantly longer benefit than standard cortisone products and with substantially lower concentration levels of chondrocyte exposure to the steroid. Hyaluronic acid was added to the options for intra-articular injection in osteoarthritis of the knee in the late 1990s and remains widely used despite some controversy over its efficacy. Although guidelines for the use of hyaluronic acid for management of osteoarthritis of the knee have varied widely, careful analysis of the data and patient's perceived efficacy indicate its continued and important role in managing osteoarthritis of the knee. Finally, the past 15 years have seen an explosion in the use of biologics including platelet-rich plasma and pluripotential (often termed stem) cells. The science behind their use and efficacy is evolving and continued study is warranted.
