Aging and the etiopathogenesis and treatment of osteoarthritis.

Knee OA in the older adult is often the result of multiple factors, some of which are intrinsic to the joint tissues and related to aging and others, such as obesity, which are extrinsic and influence the rate of development and severity of the disease. Obesity and quadricep weakness are factors that may be modifiable. The focus in managing patients with knee OA should not only be centered on the improvement of pain but also improvement in function. A combination of simple analgesics and nonpharmacologic measures, including exercises to strengthen the knee extensors, should be employed. Patients also can benefit from aerobic exercises, such as a walking or swimming program and strategies for joint protection. When medications are needed, the least toxic drugs possible should be used given the increased susceptibility of older adults to unwanted side effects.