RT Book, Section A1 Cush, John J. A2 Loscalzo, Joseph A2 Fauci, Anthony A2 Kasper, Dennis A2 Hauser, Stephen A2 Longo, Dan A2 Jameson, J. Larry SR Print(0) ID 1190523370 T1 Approach to Articular and Musculoskeletal Disorders T2 Harrison's Principles of Internal Medicine, 21e YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781264268504 LK accessmedicine.mhmedical.com/content.aspx?aid=1190523370 RD 2023/06/09 AB Musculoskeletal complaints account for >315 million outpatient visits per year and >20% of all outpatient visits in the United States. The Centers for Disease Control and Prevention estimate that 58.5 million (or 1 in 4 adults) of the U.S. population has physician-diagnosed arthritis. While many patients will have self-limited conditions requiring minimal evaluation, reassurance, and symptomatic therapy, specific musculoskeletal presentations or their persistence may herald a more serious condition that requires further evaluation or laboratory testing to establish a diagnosis. The goal of the musculoskeletal evaluation is to formulate a differential diagnosis that leads to an accurate diagnosis and timely therapy, while avoiding excessive diagnostic testing and unnecessary treatment (Table 370-1). There are several urgent conditions that must be diagnosed promptly to avoid damage and morbidity. These “red flag” diagnoses include septic arthritis, acute crystal-induced arthritis (e.g., gout), and fracture. Each may be suspected by an acute onset and monarticular or focal musculoskeletal pain.