Osteoarthritis is one of the most common types of arthritis, affecting the cartilage in the joints.

Page last updated: 02 March 2010

Over 1.6 million1 Australians are estimated to have been diagnosed with osteoarthritis, with the condition being more common among women than men.

Osteoarthritis is the arthritis of middle age. It is characterised by degenerative changes and sometimes hypertrophic changes (enlarged cells) in the bone and cartilage of one or more joints. There is also a progressive wearing down of adjacent joint surfaces with consequent distortion of joint position, usually without bony stiffening. The condition is also called degenerative arthritis, degenerative joint disease and hypertrophic arthritis.

The most common symptoms of osteoarthritis include:

  • painful joints, that usually worsen with exercise or repetitive use
  • swelling of the affected joint
  • creaking, and pain and stiffness that restrict movement
  • weakened muscles surrounding the affected joint and
  • joint deformity
Osteoarthritis is more prevalent with increasing age, although the average age of onset is about 45 years. Genetic factors and female gender are also predisposing factors.

The major risk factors for osteoarthritis are obesity, physical inactivity, joint trauma and injury, repetitive joint use and misalignment. Due to the modifiable nature of many of the risk factors, the effects and symptoms of osteoarthritis, in many cases, can be managed effectively and reduced considerably2.

People who are overweight have a higher risk of developing osteoarthritis, especially in weight-bearing joints like the knees. Increased weight puts significantly more pressure on joints, causing cartilage (the cushioning layer between bones in a joint) to break down faster than usual.

Jobs that involve repetitious physical activity, overworking of the joints and the fatiguing of muscles that protect joints tend to increase the risk of osteoarthritis in those joints.

See prevention, treatment and self-management of arthritis for management strategies, which focus on improving functioning and quality of life and alleviating pain.

1 Page 16, 2007-08 National health survey: summary of results report by the ABS, May 2009
2 Page 66, Arthritis and osteoporosis in Australia 2008, AIHW, December 2008

Page last reviewed: 23 August 2010