Osteoarthritis, also known as hypertrophic osteoarthritis, osteoarthrosis, and degenerative joint disease, is the most common form of arthritis. A chronic disease, it causes deterioration of the joint cartilage and formation of reactive new bone at the margins and subchondral areas of the joints. This degeneration results from a breakdown of chondrocytes, usually in the hips and knees.
Osteoarthritis is widespread, occurring equally in both sexes until age 55. After age 55, incidence is higher in women. Incidence is after age 40; its earliest symptoms generally begin in middle age and may progress with advancing age.
The degree of disability depends on the site and severity of involvement; it can range from minor limitation of the fingers to severe disability in persons with hip or knee involvement. The rate of progression varies, and joints may remain stable for years in an early stage of deterioration.
Primary osteoarthritis, a normal part of aging, results from many things, including metabolic, genetic, chemical, and mechanical factors. Secondary osteoarthritis usually follows an identifiable predisposing event—most commonly trauma, congenital deformity, or obesity—and leads to degenerative changes.
Signs and symptoms
The most common symptom of osteoarthritis is a deep, aching joint pain, particularly after exercise or weight bearing, usually relieved by rest. Other symptoms include:
stiffness in the morning and after exercise (relieved by rest)
aching during changes in weather (joint pain in rainy weather)
“grating” of the joint during motion
altered gait contractures
Involvement of the interphalangeal joints produces irreversible changes in the distal joints (Heberden’s nodes) and the proximal joints (Bouchard’s nodes). These nodes can be painless initially, with gradual progression to or sudden flare-ups of redness, swelling, tenderness, and impaired sensation and dexterity.
These symptoms increase with poor posture, obesity, and occupational stress.
Osteoarthritis of the interphalangeal joints produces irreversible changes in the distal joints (Heberden’s nodes) and proximal joints (Bouchard’s nodes). These nodes may be painless at first but eventually become red, swollen, and tender, causing numbness and loss of dexterity. (See Viewing osteoarthritis.)