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  • History suggests noninflammatory joint pain (ie, worse with activity, better with rest).

  • Examination suggests joint line tenderness and bony enlargement.

  • Radiographs demonstrate joint space narrowing, osteophytes, sclerosis, and bone cysts.


A. Prevalence & Impact

Osteoarthritis (OA) is a highly prevalent, disabling, and costly disease. More than a tenth of the adult population has symptomatic OA, and more than a quarter of those >70 years of age have self-reported arthritis. It was recently estimated that 14 million people in the United States have symptomatic knee OA. OA is also a known cause of disability, and having the diagnosis is associated with a decrease in quality-adjusted life-years. In the United States and other developed countries, the cost of OA has been estimated to account for approximately 1% to 2.5% of the gross national product. Most direct costs of OA are due to hospital stays (especially during or after joint replacement surgery) and rehabilitation care. Other direct costs are attributed to medications, provider visits, other health professional visits, and diagnostic procedures. Indirect costs are largely due to productivity losses from reduced employment rate, absenteeism, presenteeism (decrease in productivity even when at work), and early retirement. As such, OA has been designated as a serious disease by the US Food and Drug Administration (FDA) for the reasons summarized in Table 34–1.

Table 34–1.Reasons why osteoarthritis (OA) is a serious disease.

B. Risk Factors

Several factors can increase the likelihood of developing OA, and risk factors can be divided into systemic- and joint-level risk factors (Table 34–2). Increased age is a well-known risk factor for OA, particularly among women age 50 and older. Women, compared to men, are more ...

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